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Intel
®
852GM/852GMV Chipset
Graphics and Memory Controller
Hub (GMCH)
Datasheet
June 2004
Order Number: 252407-004
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2 Intel
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852GM/852GMV Chipset GMCH Data sheet
Information in this document is provided in connection with Intel products. No license, express or implied, by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Intel’s Terms and Conditions of Sale for such products, Intel assumes no liability
whatsoever, and Intel disclaims any express or implied warranty, relating to sale and/or use of Intel products including liability or warranties relating to
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Actual system-level properties, such as skin temperature, are a function of various factors, including component placement, component power
characteristics, system power and thermal management techniques, software application usage and general system design. Intel is not responsible for its
customers’ system designs, nor is Intel responsible for ensuring that its customers’ products comply with all applicable laws and regulations. Intel provides
this and other thermal design information for informational purposes only. System design is the sole responsibility of Intel’s customers, and Intel’s
customers should not rely on any Intel-provided information as either an endorsement or recommendation of any particular system design characteristics.
Intel may make changes to specifications and product descriptions at any time, without notice.
Designers must not rely on the absence or characteristics of any features or instructions marked "reserved" or "undefined." Intel reserves these for future
definition and shall have no responsibility whatsoever for conflicts or incompatibilities arising from future changes to them.
The Intel 852GM/852GMV Chipset Graphics and Memory Controller Hub (GMCH) may contain design defects or errors known as errata which may cause
the product to deviate from published specifications. Current characterized errata are available on request.
Contact your local Intel sales office or your distributor to obtain the latest specifications and before placing your product order.
I
2
C is a 2-wire communications bus/protocol developed by Philips*. SMBus is a subset of the I
2
C bus/protocol and was developed by Intel.
Implementations of the I
2
C bus/protocol may require licenses from various entities, including Philips Electronics N.V. and North American Philips
Corporation.
Alert on LAN* is a result of the Intel and IBM* Advanced Manageability Alliance and a trademark of IBM.
Copies of documents which have an ordering number and are referenced in this document, or other Intel literature, may be obtained from:
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or call 1-800-548-4725
Intel, Celeron, the Intel logo, Pentium, and Intel SpeedStep are registered trademarks or trademarks of Intel Corporation and its subsidiaries in the United
States and other countries.
*Other brands and names may be claimed as the property of others.
Copyright © Intel Corporation 2003-2004
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Intel
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852GM/852GMV Chipset GMCH Data sheet 3
Contents
1.
Introduction .................................................................................................................................19
1.1.
Terminology ...................................................................................................................19
1.2.
Reference Documents ...................................................................................................20
1.3.
System Architecture Overview.......................................................................................21
1.3.1.
Intel 852GM GMCH System Architecture.........................................................21
1.3.2.
Intel 852GMV GMCH System Architecture ......................................................21
1.4.
Processor Host Interface ...............................................................................................23
1.4.1.
Intel 852GM GMCH Processor Host Interface .................................................23
1.4.2.
Intel 852GMV GMCH Processor Host Interface...............................................24
1.5.
Intel 852GM/852GMV GMCH Host Bus Error Checking ...............................................24
1.6.
Intel 852GM/852GMV GMCH System Memory Interface..............................................24
1.7.
Intel 852GM/852GMV GMCH Internal Graphics ...........................................................25
1.7.1.
Intel 852GM/852GMV GMCH Analog Display Port..........................................25
1.7.2.
Intel 852GM/852GMV GMCH Integrated LVDS Port .......................................25
1.7.3.
Intel 852GM/852GMV GMCH Integrated DVO Port.........................................26
1.8.
Hub Interface .................................................................................................................26
1.9.
Address Decode Policies...............................................................................................26
1.10.
Intel 852GM/852GMV GMCH Clocking .........................................................................26
1.11.
System Interrupts...........................................................................................................27
2.
Signal Description.......................................................................................................................29
2.1.
Host Interface Signals....................................................................................................30
2.2.
DDR SDRAM Interface ..................................................................................................33
2.3.
Hub Interface Signals.....................................................................................................34
2.4.
Clocks ............................................................................................................................35
2.5.
Internal Graphics Display Signals..................................................................................37
2.5.1.
Dedicated LFP LVDS Interface ........................................................................37
2.5.2.
Digital Video Port C (DVOC) ............................................................................38
2.5.3.
Analog Display..................................................................................................39
2.5.4.
General Purpose Input/Output Signals.............................................................40
2.6.
Voltage References, PLL Power....................................................................................42
3.
Register Description ...................................................................................................................45
3.1.
Conceptual Overview of the Platform Configuration Structure ......................................45
3.2.
Nomenclature for Access Attributes ..............................................................................46
3.3.
Standard PCI Bus Configuration Mechanism ................................................................47
3.4.
Routing Configuration Accesses....................................................................................47
3.4.1.
PCI Bus #0 Configuration Mechanism .............................................................47
3.4.2.
Primary PCI and Downstream Configuration Mechanism................................47
3.5.
Register Definitions........................................................................................................48
3.6.
I/O Mapped Registers ....................................................................................................49
3.6.1.
CONFIG_ADDRESS – Configuration Address Register..................................49
3.6.2.
CONFIG_DATA – Configuration Data Register ...............................................51
3.7.
VGA I/O Mapped Registers ...........................................................................................52
3.8.
Intel 852GM/852GMV GMCH Host-Hub Interface Bridge Device Registers
(Device #0, Function #0) ...............................................................................................53
3.8.1.
VID – Vendor Identification...............................................................................54
3.8.2.
DID – Device Identification ...............................................................................54
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852GM/852GMV Chipset GMCH Data sheet
3.8.3.
PCICMD – PCI Command Register................................................................. 55
3.8.4.
PCI Status Register.......................................................................................... 56
3.8.5.
RID – Register Identification ............................................................................ 57
3.8.6.
SUBC – Sub Class Code ................................................................................. 57
3.8.7.
BCC – Base Class Code.................................................................................. 58
3.8.8.
HDR – Header Type......................................................................................... 58
3.8.9.
SVID – Subsystem Vendor Identification ......................................................... 58
3.8.10.
SID – Subsystem Identification ........................................................................ 59
3.8.11.
CAPPTR – Capabilities Pointer ....................................................................... 59
3.8.12.
CAPID Capability Identification Register (Device 0) ..................................... 60
3.8.13.
RRBAR – Register Range Base Address Register (Device 0) ........................ 61
3.8.14.
GMC – GMCH Miscellaneous Control Register (Device 0) ............................. 62
3.8.15.
GGC – GMCH Graphics Control Register (Device 0)...................................... 63
3.8.16.
DAFC – Device and Function Control Register (Device 0).............................. 64
3.8.17.
FDHC – Fixed DRAM Hole Control Register (Device 0).................................. 64
3.8.18.
PAM(6:0) – Programmable Attribute Map Register (Device 0)........................ 65
3.8.19.
SMRAM – System Management RAM Ctrl Register (Device 0) ...................... 69
3.8.20.
ESMRAMC – Extended System Management RAM Control (Device 0) ......... 70
3.8.21.
ERRSTS – Error Status Register (Device 0) ................................................... 71
3.8.22.
ERRCMD – Error Command Register (Device 0)............................................ 72
3.8.23.
SMICMD – SMI Error Command Register (Device 0) ..................................... 74
3.8.24.
SCICMD – SCI Error Command Register (Device 0) ...................................... 75
3.8.25.
CAPD – Capability Disable Bits ....................................................................... 75
3.9.
Intel 852GM/852GMV GMCH Main Memory Control, Memory I/O Control Registers
(Device #0, Function #1) ............................................................................................... 76
3.9.1.
VID – Vendor Identification .............................................................................. 77
3.9.2.
DID – Device Identification............................................................................... 77
3.9.3.
PCICMD – PCI Command Register................................................................. 78
3.9.4.
PCISTS – PCI Status Register ........................................................................ 79
3.9.5.
RID – Revision Identification............................................................................ 80
3.9.6.
SUBC – Sub-Class Code................................................................................. 80
3.9.7.
BCC – Base Class Code.................................................................................. 80
3.9.8.
HDR – Header Type......................................................................................... 81
3.9.9.
SVID – Subsystem Vendor Identification ......................................................... 81
3.9.10.
SID – Subsystem Identification ........................................................................ 81
3.9.11.
CAPPTR – Capabilities Pointer ....................................................................... 82
3.9.12.
DRB – DRAM Row Boundary Register - Device #0 ........................................ 82
3.9.13.
DRA – DRAM Row Attribute Register - Device #0 .......................................... 83
3.9.14.
DRT – DRAM Timing Register - Device #0...................................................... 84
3.9.15.
PWRMG – DRAM Controller Power Management Control Register - Device #087
3.9.16.
DRC – DRAM Controller Mode Register - Device #0 ...................................... 88
3.9.17.
DTC – DRAM Throttling Control Register (Device 0) ...................................... 90
3.10.
Intel 852GM/852GMV GMCH Configuration Process and Registers (Device #0,
Function #3) .................................................................................................................. 94
3.10.1.
VID – Vendor Identification .............................................................................. 94
3.10.2.
DID – Device Identification............................................................................... 95
3.10.3.
PCICMD – PCI Command Register................................................................. 96
3.10.4.
PCISTS – PCI Status Register ........................................................................ 97
3.10.5.
RID – Revision Identification............................................................................ 98
3.10.6.
SUBC – Sub-Class Code................................................................................. 98
3.10.7.
BCC – Base Class Code.................................................................................. 98
3.10.8.
HDR – Header Type......................................................................................... 99
3.10.9.
SVID – Subsystem Vendor Identification ......................................................... 99
3.10.10.
ID – Subsystem Identification .......................................................................... 99
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Intel
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852GM/852GMV Chipset GMCH Data sheet 5
3.10.11.
CAPPTR – Capabilities Pointer......................................................................100
3.10.12.
HPLLCC – HPLL Clock Control Register (Device 0)......................................100
3.11.
Intel 852GM/852GMV GMCH Integrated Graphics Device Registers (Device #2,
Function #0).................................................................................................................101
3.11.1.
VID2 – Vendor Identification Register – Device #2 ........................................102
3.11.2.
DID2 – Device Identification Register - Device #2 .........................................102
3.11.3.
PCICMD2 – PCI Command Register - Device #2 ..........................................103
3.11.4.
PCISTS2 – PCI Status Register - Device #2..................................................104
3.11.5.
RID2 – Revision Identification Register - Device #2.......................................104
3.11.6.
CC – Class Code Register - Device #2 ..........................................................105
3.11.7.
CLS – Cache Line Size Register - Device #2.................................................105
3.11.8.
MLT2 – Master Latency Timer Register - Device #2......................................105
3.11.9.
HDR2 – Header Type Register - Device #2 ...................................................106
3.11.10.
GMADR – Graphics Memory Range Address Register - Device #2 ..............106
3.11.11.
MMADR – Memory Mapped Range Address Register - Device #2 ...............107
3.11.12.
IOBAR – I/O Base Address Register - (Device #2)........................................107
3.11.13.
SVID2 – Subsystem Vendor Identification Register - Device #2....................108
3.11.14.
SID2 – Subsystem Identification Register - Device #2...................................108
3.11.15.
ROMADR – Video BIOS ROM Base Address Registers - Device #2 ............108
3.11.16.
INTRLINE Interrupt Line Register - Device #2.............................................109
3.11.17.
INTRPIN Interrupt Pin Register - Device #2 ................................................109
3.11.18.
MINGNT – Minimum Grant Register - Device #2 ...........................................109
3.11.19.
MAXLAT – Maximum Latency Register - Device #2 ......................................109
3.11.20.
PMCAP – Power Management Capabilities Register - Device #2.................110
3.11.21.
PMCS – Power Management Control/Status Register - Device #2 ...............110
4.
Intel 852GM/852GMV GMCH System Address Map ...............................................................111
4.1.
System Memory Address Ranges ...............................................................................111
4.2.
Compatibility Area........................................................................................................113
4.3.
Extended System Memory Area ..................................................................................115
4.4.
Main System Memory Address Range (0010_0000h to Top of Main Memory) ..........116
4.4.1.
15 MB-16 MB Window....................................................................................116
4.4.2.
Pre-allocated System Memory .......................................................................116
4.4.2.1.
Extended SMRAM Address Range (HSEG and TSEG) ...............117
4.4.2.2.
HSEG ............................................................................................117
4.4.2.3.
TSEG.............................................................................................117
4.4.2.4.
Intel Dynamic Video Memory Technology (DVMT).......................117
4.4.2.5.
PCI Memory Address Range (Top of Main System Memory
to 4 GB).........................................................................................117
4.4.2.6.
APIC Configuration Space (FEC0_0000h -FECF_FFFFh,
FEE0_0000h- FEEF_FFFFh)........................................................118
4.4.2.7.
High BIOS Area (FFE0_0000h -FFFF_FFFFh) ............................118
4.4.3.
System Management Mode (SMM) Memory Range ......................................118
4.4.3.1.
SMM Space Restrictions...............................................................119
4.4.3.2.
SMM Space Definition...................................................................119
4.4.4.
System Memory Shadowing...........................................................................119
4.4.5.
I/O Address Space .........................................................................................119
4.4.6.
GMCH Decode Rules and Cross-Bridge Address Mapping...........................120
4.4.7.
Hub Interface Decode Rules ..........................................................................120
4.4.7.1.
Hub Interface Accesses to GMCH that Cross Device
Boundaries ....................................................................................121
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852GM/852GMV Chipset GMCH Data sheet
5.
Functional Description.............................................................................................................. 123
5.1.
Host Interface Overview .............................................................................................. 123
5.2.
Dynamic Bus Inversion................................................................................................ 123
5.2.1.
System Bus Interrupt Delivery ....................................................................... 123
5.2.2.
Upstream Interrupt Messages........................................................................ 124
5.3.
System Memory Interface ........................................................................................... 124
5.3.1.
DDR SDRAM Interface Overview .................................................................. 124
5.3.2.
System Memory Organization and Configuration .......................................... 124
5.3.2.1.
Configuration Mechanism for SO-DIMMs..................................... 124
5.3.2.2.
System Memory Register Programming....................................... 125
5.3.3.
DDR SDRAM Performance Description......................................................... 125
5.4.
Integrated Graphics Overview..................................................................................... 126
5.4.1.
3D/2D Instruction Processing ........................................................................ 126
5.4.2.
3D Engine ...................................................................................................... 127
5.4.2.1.
Setup Engine ................................................................................ 127
5.4.2.2.
Viewport Transform and Perspective Divide ................................ 127
5.4.2.3.
3D Primitives and Data Formats Support..................................... 127
5.4.2.4.
Pixel Accurate Fast Scissoring and Clipping Operation............... 128
5.4.2.5.
Backface Culling........................................................................... 128
5.4.2.6.
Scan Converter............................................................................. 128
5.4.2.7.
Texture Engine ............................................................................. 128
5.4.2.8.
Perspective Correct Texture Support ........................................... 128
5.4.2.9.
Texture Decompression ............................................................... 128
5.4.2.10.
Texture Chromakey ...................................................................... 129
5.4.2.11.
Anti-Aliasing.................................................................................. 129
5.4.2.12.
Texture Map Filtering.................................................................... 129
5.4.2.13.
Multiple Texture Composition ....................................................... 130
5.4.2.14.
Cubic Environment Mapping ........................................................ 130
5.4.2.15.
Bump Mapping.............................................................................. 130
5.4.3.
Raster Engine ................................................................................................ 130
5.4.3.1.
Texture Map Blending .................................................................. 131
5.4.3.2.
Combining Intrinsic and Specular Color Components.................. 131
5.4.3.3.
Color Shading Modes ................................................................... 132
5.4.3.4.
Color Dithering.............................................................................. 132
5.4.3.5.
Vertex and Per Pixel Fogging....................................................... 132
5.4.3.6.
Alpha Blending.............................................................................. 132
5.4.3.7.
Color Buffer Formats: (Destination Alpha) ................................... 133
5.4.3.8.
Depth Buffer.................................................................................. 133
5.4.3.9.
Stencil Buffer ................................................................................ 133
5.4.3.10.
Projective Textures....................................................................... 134
5.4.4.
2D Engine ...................................................................................................... 134
5.4.4.1.
256-Bit Pattern Fill and BLT Engine ............................................. 134
5.4.4.2.
Alpha Stretch BLT......................................................................... 134
5.4.5.
Planes and Engines ....................................................................................... 135
5.4.5.1.
Dual Pipe Independent Display Functionality............................... 135
5.4.6.
Hardware Cursor Plane.................................................................................. 135
5.4.6.1.
Cursor Color Formats ................................................................... 135
5.4.6.2.
Popup Plane (Second Cursor)...................................................... 135
5.4.6.3.
Popup Color Formats ................................................................... 136
5.4.7.
Overlay Plane................................................................................................. 136
5.4.7.1.
Multiple Overlays (Display C) ....................................................... 136
5.4.7.2.
Source/Destination Color/Chromakeying ..................................... 136
5.4.7.3.
Gamma Correction ....................................................................... 136
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Intel
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852GM/852GMV Chipset GMCH Data sheet 7
5.4.7.4.
YUV to RGB Conversion...............................................................136
5.4.7.5.
Color Control .................................................................................136
5.4.7.6.
Dynamic Bob and Weave..............................................................136
5.4.8.
Video Functionality .........................................................................................137
5.4.8.1.
MPEG-2 Decoding ........................................................................137
5.4.8.2.
Hardware Motion Compensation ..................................................137
5.4.8.3.
Sub-picture Support ......................................................................137
5.5.
Display Interface ..........................................................................................................138
5.5.1.
Analog Display Port Characteristics ...............................................................138
5.5.1.1.
Integrated RAMDAC .....................................................................138
5.5.1.2.
DDC (Display Data Channel) ........................................................138
5.5.2.
Digital Display Interface..................................................................................138
5.5.2.1.
Dedicated LVDS Interface.............................................................138
5.5.2.2.
LVDS Interface Signals .................................................................139
5.5.2.3.
LVDS Pair States ..........................................................................139
5.5.2.4.
Single Channel versus Dual Channel Mode .................................140
5.5.2.5.
LVDS Channel Skew.....................................................................140
5.5.2.6.
LVDS PLL .....................................................................................140
5.5.2.7.
SSC Support .................................................................................140
5.5.2.8.
Panel Power Sequencing..............................................................140
5.5.2.9.
Back Light Inverter Control ...........................................................142
5.5.2.10.
Digital Video Output Port...............................................................142
6.
Power and Thermal Management ............................................................................................143
6.1.
General Description of Supported CPU States ...........................................................144
6.2.
General Description of ACPI States ............................................................................144
6.3.
Enhanced Intel SpeedStep Technology Overview ......................................................145
6.4.
Internal Thermal Sensor ..............................................................................................145
6.4.1.
Hardware Throttling ........................................................................................145
6.4.2.
Register Locking.............................................................................................145
6.4.3.
Hysteresis Operation ......................................................................................146
6.5.
External Thermal Sensor Input ....................................................................................146
6.5.1.
Usage .............................................................................................................146
7.
Testability..................................................................................................................................147
7.1.
XOR Test Mode Entry..................................................................................................147
7.2.
XOR Chain Differential Pairs .......................................................................................149
7.3.
XOR Chain Exclusion List............................................................................................149
7.4.
XOR Chain Connectivity/Ordering ...............................................................................150
7.4.1.
VCC/VSS Voltage Groups..............................................................................162
8.
Intel 852GM/852GMV GMCH Strap Pins .................................................................................163
8.1.
Strapping Configuration ...............................................................................................163
9.
Ballout and Package Information..............................................................................................165
9.1.
Package Mechanical Information.................................................................................173
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852GM/852GMV Chipset GMCH Data sheet
Figures
Figure 1. Configuration Address Register................................................................................ 49
Figure 2. Configuration Data Register ..................................................................................... 51
Figure 3. PAM Registers .......................................................................................................... 67
Figure 4. Simplified View of System Address Map ................................................................112
Figure 5. Detailed View of System Address Map................................................................... 113
Figure 6. Intel 852GM/852GMV GMCH Graphics Block Diagram ......................................... 126
Figure 7. Panel Power Sequencing .......................................................................................141
Figure 8. XOR–Tree Chain ....................................................................................................147
Figure 9. XOR Chain Test Mode Entry Events Diagram .......................................................148
Figure 10. ALLZ Test Mode Entry Events Diagram ...............................................................148
Figure 11. Intel 852GM/852GMV GMCH Ballout Diagram (Top View)..................................165
Figure 12. Intel 852GM/852GMV GMCH Micro-FCBGA Package Dimensions (
Top View)................................................................................................................173
Figure 13. Intel 852GM/852GMV GMCH Micro-FCBGA Package Dimensions
(Side View) .............................................................................................................174
Figure 14. Intel 852GM/852GMV GMCH Micro-FCBGA Package Dimensions
(Bottom View) .........................................................................................................175
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Tables
Table 1. DDR Memory Capacity.............................................................................................. 24
Table 2. Intel 852GM/852GMV GMCH Interface Clocks......................................................... 27
Table 3. Host Interface Signal Descriptions ............................................................................ 30
Table 4. DDR SDRAM Interface Descriptions......................................................................... 33
Table 5. Hub Interface Signals ................................................................................................ 34
Table 6. Clock Signals............................................................................................................. 35
Table 7. Dedicated LVDS Flat Panel Interface Signal Descriptions........................................ 37
Table 8. Digital Video Port C (DVOC) Signal Descriptions ..................................................... 38
Table 9. Analog Display Signal Descriptions........................................................................... 39
Table 10. Intel 852GM/852GMV GMCH GPIO (DDC, I2C, etc.) Signal Descriptions............. 40
Table 11. Voltage References, PLL Power ............................................................................. 42
Table 12. Device Number Assignment.................................................................................... 45
Table 13. Nomenclature for Access Attributes ........................................................................ 46
Table 14. VGA I/O Mapped Register List ................................................................................ 52
Table 15. Index – Data Registers ............................................................................................ 52
Table 16. GMCH Configuration Space - Device #0, Function#0............................................. 53
Table 17. Attribute Bit Assignment .......................................................................................... 66
Table 18. PAM Registers and Associated System Memory Segments .................................. 67
Table 19. Host-Hub I/F Bridge/System Memory Controller Configuration Space
(Device #0, Function#1)........................................................................................... 76
Table 20. Configuration Process Configuration Space (Device#0, Function #3) .................... 94
Table 21. Intel 852GM/852GMV GMCH Configurations ....................................................... 100
Table 22. Integrated Graphics Device Configuration Space (Device #2, Function#0).......... 101
Table 23. System Memory Segments and Their Attributes................................................... 114
Table 24. Pre-allocated System Memory .............................................................................. 116
Table 25. SMM Space Transaction Handling........................................................................ 119
Table 26. Relation of DBI Bits to Data Bits............................................................................ 123
Table 27. Data Bytes on SO-DIMM Used for Programming DRAM Registers...................... 125
Table 28. Dual Display Usage Model (Intel 852GM/852GMV GMCH).................................. 135
Table 29. Panel Power Sequencing Timing Parameters....................................................... 142
Table 30. Enhanced Intel SpeedStep Technology Overview................................................ 145
Table 31. Differential Signals in the XOR Chains.................................................................. 149
Table 32. XOR Chain Exclusion List of Pins ......................................................................... 149
Table 33. XOR Mapping ........................................................................................................ 151
Table 34. Voltage Levels and Ball Out for Voltage Groups................................................... 162
Table 35. Strapping Signals and Configuration..................................................................... 163
Table 36. Ballout Table.......................................................................................................... 166
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Revision History
Document No. Rev. Description Date
252407 001 Initial release January 2003
252407 002 Revisions include:
Added support for Intel Celeron M processor
January 2004
252407 003 Revisions include:
Added 852GMV features and system diagram to features section
February
2004
252407 004 Revisions include:
Added support for Intel Celeron D processor on 90 nm process
and in the 478-pin package
June 2004
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Intel
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852GM/852GMV Chipset GMCH Data sheet 11
Intel® 852GM Chipset GMCH Product Features
Processor/Host Bus Support
Intel
®
Celeron
®
processor (478-pin
package)
Supports the processor subset of the
Enhanced Mode Scalable bus
protocol 2X Address, 4X data
Intel Celeron processor System Bus
interrupt delivery
Mobile Intel
®
Pentium
®
4 Processor-M
(478-pin package)
Supports the subset of the Enhanced
Mode Scalable bus protocol
Mobile Intel Pentiu m 4 Pro cessor-M
System Bus interrupt delivery
Supports system bus at 400-MHz or
3.2 GB/s
Supports host Dynamic Bus
Inversion (DBI)
Supports 32-bit host bus addressing
12-deep In-Order-Queue
AGTL+ bus driver technology with
integrated AGTL termination
resistors
Supports Enhanced Intel SpeedStep
®
technology
Intel
®
Celeron
®
M processor
400-MHz front side bus frequency.
Source synchron ous double pum ped
address (2X)
Source synchronous quad pumped
data (4X)
FSB interrupt delivery
Supports Host bus dynamic bus
inversion (DBI )
Supports 32-bit host bus addressing
8-deep in-order queue
AGTL+ bus driver technology with
integrated AGTL+ termination
resistors
Memory System
Directly supports one DDR SDRAM
channel, 64-bits wide
Supports 200/266-MHz DDR SDRAM
devices with max of 2 Double-Sided SO-
DIMMs (4 rows populated) with
unbuffered PC1600/PC2100 DDR
Triangle Lists, Strips and Fans
support
SDRAM (without ECC)
Supports 128-Mbit, 256-Mbit, and 512-
Mbit technologies providing maximum
capacity of 1-GB with x16 devices and up
to 2-GB with high density 512-Mbit
technology
All supported devices have 4 banks
Supports up to 16 simultaneous open pages
Supports page si zes of 2- kB, 4- kB, 8 -kB,
and 16-kB. Page size is individually
selected for every row (UMA support only)
System Interrupts
Supports Intel 8259 and FSB interrupt
delivery mechanism
Supports interrupts signaled as upstream
Memory Writes from PCI and Hub
Interface
MSI sent to the CPU through the System
Bus
Internal Graphics Features
Up to 64-MB of Dynamic Video Memory
Allocation
Display Image Rotation
Core Frequency
Display Core frequency of 133-MHz
Render Core frequency of 133-MHz
2D Graphics Engine
Optimized 128-bit BLT engine
Ten programmabl e and predefined
monochrome patterns
Alpha Stretch Blt (via 3D pipeline)
Anti-aliased lines
Hardware-based BLT Clipping and
Scissoring
32-bit Alpha Blended cursor
Programmable 64 x 64 3-color
Transparent cursor
Color Space Conversion
3 Operand Raster BLTs
8-bit, 16-bit, and 32-bit color
ROP support
DIB translation an d Linear/Tile
addressing
3D Graphics Engine
3D Setup and Render Engine
Viewpoint Transform and Perspective
Divide
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12 Intel
®
852GM/852GMV Chipset GMCH Data sheet
Indexed Vertex and Flexible Vertex
formats
Pixel accurate Fast Scissoring and
Clipping operation
Backface Culling support
DirectX* and OGL Pixelization
rules
Anti-Aliased Lines support and
Sprite Points support
Provides the highest sustained fill
rate performance in 32-bit color and
24-bit W m ode
High quality performance Texture
Engine
266-Mega Texel/s peak performance
Per Pixel Perspective Corrected
Texture Mapping
Single Pass Texture
Compositing(Multi-Textures) at rate
Enhanced Texture Blending
functions
IOxAPIC in ICH4-M provides
redirection for upstream interrupts to the
System Bus
Video Stream Decoder
HW Motion Compensation for MPEG2
All format decoder (18 ATSC formats)
supported
Dynamic Bob and Weave support for
Video Streams
Support for stand ard definition DVD
quality encodin g at low CPU utilization
Video Ove rl a y
Single high quality scalable Overlay and
second Sprite to support second Overlay
Multiple Overlay functiona lity provided
via Arithmetic Stretch BLT (Block
Transfer)
5-tap horizontal, 3-tap vertical filtered
scaling
Multiple Overlay formats
Direct YUV from Overlay to
TV-out
Independent Gamma Correction
Independent Brightn e ss / Contrast /
Saturation
Independent Tint / Hue support
Color Specular Lighting
Z Bias support
Dithering
Line and Full-Scene Anti-Aliasing
16 and 24-bit Z Buffering
Destination Colorkeying
Source Chromakeying
Multiple hardware color cursor support (32-bit
with alpha and legacy 2-bpp mode)
Accompanying I2C and DDC channels
provided throug h multip lexed interface
Display
Analog Display Support
350-MHz integrated 24-bit RAMDAC
that can drive a standard pro gr essi ve
scan analog monitor with pixel
resolution up to 1600x1200 at 85-Hz
and up to 1920x1440 at 60-Hz
Dual independent pipe support
Concurrent: Different images and
native display timings on each display
device
DVO (DVOC) support
Digital video out port DVO C with
165-MHz dot clock on 12-bit double
pumped interface
Digital video out port DVO C with
165-MHz dot clock on 12-bit double
pumped interface
Variety of DVO devices sup p ort ed
Compliant with DVI Specification 1.0
Support display resolutio n up to
1400x1050 @ 75 Hz
Dedicated LFP (local flat panel)
LVDS interface
Twelve Level of Detail MIP Map
Sizes from 1x1 to 2 Kx2 K
Numerous Texture formats including
32-bit RGBA
Alpha and Luminance Maps
Texture Chromakeying
Bilinear, Trilinear, and Anisotropic
MIP-Mapped Filtering
Cubic Environment Reflection
Mapping
Embossed Bump-Mapping
DXTn Texture Decompression
FX1 Texture Compression
3D Graphics Rasterization
enhancements
One Pixel per clock
Flat and Gouraud Shading
Color Alpha Blending for
Transparency
Vertex and Programmable Pixel Fog
Atmospheric effects
Compliant with ANSI/TIA/EIA –644-1995
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Intel
®
852GM/852GMV Chipset GMCH Data sheet 13
16 and 24-bit W B uf feri n g
8-bit Stencil Buffering
Double and Triple Render Buffer
support
16 and 32-bit color
Destination Alpha
Vertex Cache
Maximum 3D resolut ion of
backlight inverter control
Bi-linear Panel fitting
1600x1200 at 85-Hz (contact your
Intel Field Representative for
detailed display information, i.e.
pixel depths, etc.)
Optimal 3D resolution supported
Fast Clear support
ROP support
Hub Interface to ICH4-M
266 MB/s point-to-point Hub Interface to
ICH4-M
66-MHz base clock
specification
Integrated PWM interface for LCD
backlight inverter control
Bi-linear Panel fitting
Package
732-pin Micro-FCBGA (37.5 x 37.5 mm)
Power Management
SMRAM space remapping to A0000h (128
kB)
Supports extended SMRAM space above
256-MB, additional 1-MB TSEG from Top
of Memory, cacheable (cacheability
controlled by CPU)
APM Rev 1.2 com pl i a nt pow e r
management
Supports Suspend to System Memory (S3),
Suspend to Dis k (S4 ) a n d Hard Off/Total
Reboot (S5)
ACPI 1.0b, 2.0 Support
Single or dual channel L V DS panel
support up to SXGA+(1400x1050 60-Hz)
panel resolution with frequency range from
25-MHz to 112-MHz (single channel/dual
channel)
SSC support of 0.5%, 1.0%, and 2.5%
center and down spread with external SSC
clock
Supports data format of 18-bpp
LCD panel power sequencin g compliant
with SPWG timing specification
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14 Intel
®
852GM/852GMV Chipset GMCH Data sheet
Intel
®
852GMV Chipset GMCH
Product Features
Note: The Intel 852GMV chipset GMCH shares the same chipset features as the Intel 852GM chipset along
with the additional features:
Processor/Host Bus Support
Intel Celeron processor (478-pin FCPGA
package, 0.13 micron process)
2X Address, 4X data
Intel Celeron processor FSB interrupt
delivery
Supports system bus at 400 MHz with Intel
Celeron processor (0.13 micron process)
Supports system bus at 533 MHz with Intel
Celeron D processor on 90 nm process and
in the 478-pin package
Memory System
Supports 200/266-MHz DDR SDRAM
devices with max of 2 Double-Sided SO-
DIMMs (4 rows populated) with unbuffered
PC1600/PC2100 DDR SDRAM
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Intel
®
852GM/852GMV Chipset GMCH Data sheet 15
Mobile Intel Pentium 4 Processor-M or Mobile Intel Celeron Process or and Intel 852GM Chipset
Block Diagram
852GM
GMCH
732 Micro-FCBGA
400MHz
Panel
DVO Device DVO
LVDS
ICH4-M
421 BGA
ATA100 IDE (2)
USB 2.0/1. 1 (6)
CRT RGB
Audio Codec
Audio
Codec
AC’97 2.2
FWH SIO
KBC
LPC Cardbus
Moon2
PCI 33MHz
266 MHz HUB
Interface
LAN
200/266MHz
DDR
PC1600/PC2100
Mobile Int e l Pent ium
4 Processor-M or
Mobile Int e l Celeron
p
rocessor
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16 Intel
®
852GM/852GMV Chipset GMCH Data sheet
Intel Celeron M Processor and Intel 852GM GMCH Chipset System Block Diagram
Processor
852GM
GMCH
732 Micro-FCBGA
400MHz
Panel
DVO Device
DVO
LVDS
ICH4-M
421 BGA
ATA100 IDE (2)
USB 2.0/1. 1 (6)
CRT
RGB
Audio Codec
Audio
Codec
AC’97 2.2
FWH SIO
KBC
LPC I/P Cardbus
Moon2
PCI 33MHz
266 MHz HUB
Interface
LAN
200/266MHz
DDR
PC1600/PC2100
Intel Celeron M
R
Intel
®
852GM/852GMV Chipset GMCH Data sheet 17
Intel Celeron Processor, Intel Cele ron D Processor on 90 nm process and in the 478-pin package
and Intel 852GMV GMCH Chipset System Block Diagram
Intel Celeron
processor or
Intel Celeron D
processor
852GMV
GMCH
732 Micro-FCBGA
400/533MHz
Panel
DVO Device DVO
LVDS
ICH4-M
421 BGA
ATA100 IDE (2)
USB 2.0/1. 1 (6)
CRT RGB
Audio Codec
Audio Codec
AC’97 2.2
FWH SIO
KBC
LPC Cardbus
Moon2
PCI 33MHz
266 MHz HUB
Interface
LAN
200/266MHz
DDR
PC1600/PC2100
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18 Intel
®
852GM/852GMV Chipset GMCH Data sheet
This page intention a lly left blank
Introduction
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 19
1. Introduction
This document provides the design specifications for the Intel
®
852GM/GMVchipsets.
1.1. Terminology
Term Description
BLI Back Light Inverter
Core The internal base logic in the Intel 852GM/852GMV GMCH
CPIS Common Panel Interface Specification
CPU Central Processing Unit
DBI Dynamic Bus inversion
DBL Display Brightness Link
DVO Digital Video Out
DVI* Digital Visual Interface is the interface specified by the DDWG (Digital Display Working
Group) DVI Spec. Rev. 1.0 utilizing only the Silicon Image developed T.M.D.S. protocol
DVMT Intel Dynamic Video Memory Technology
EDID Extended Display Identification Data
Full Reset A Full Intel 852GM/852GMV GMCH Reset is defined in this document when RSTIN# is
asserted
GMCH Graphics Memory Controller Hub
Hub Interface (HI) The proprietary interconnect between the Intel 852GM/852GMV GMCH and the
component. In this document, the Hub Interface cycles originating from or destined for
the ICH4-M are generally referred to as Hub Interface cycles. Hub cycles originating
from or destined for the primary PCI interface on are sometimes referred to as Hub
Interface/PCI cycles
Host This term is used synonymously with processor
IGD Integrated Graphics Device
Intel 852GM/852GMV
GMCH
Refers to the GMCH component
Intel 82801DBM ICH4-M The component contains the primary PCI interface, LPC interface, USB 2.0, ATA-100,
AC’97, and other I/O functions. It communicates with the Intel 852GM/852GMV GMCH
over a proprietary interconnect called the Hub Interface. Throughout this datasheet, the
Intel 82801DBM ICH4-M component will be referred to as the ICH4-M
IPI Inter Processor Interrupt
LFP Local Flat Panel
LVDS Low voltage differential signals used for interfacing to LCD panels
MSI Message Signaled Interrupts. MSI allow a device to request interrupt service via a
standard memory write transaction instead of through a hardware signal
Primary PCI Physical PCI bus that is driven directly by the component. It supports only 5-V, 33-MHz
PCI or PCI0 2.2 compliant components. Communication between PCI0 and Intel
Introduction
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20 Intel
®
852GM/852GMV Chipset GMCH Data sheet
Term Description
852GM/852GMV GMCH occurs over the Hub Interface. Note that although the Primary
PCI bus is referred to as PCI0, it is not PCI Bus #0 from a configuration standpoint
FSB Processor System Bus. Connection between Intel 852GM/852GMV GMCH and the
CPU. Also known as the Front Side Bus (FSB) or Host interface
PWM Pulse Width Modulation
SSC Spread Spectrum Clocking
System Bus Processor-to-Intel 852GM/852GMV GMCH interface. The Enhanced Mode of the
Scalable Bus is the P6 Bus plus enhancements, consisting of source synchronous
transfers for address and data, and system bus interrupt delivery. The Mobile Pentium 4
Processor-M processor implements a subset of Enhanced Mode
UMA Unified Memory Architecture with graphics memory for the IGD inside System Memory
VDL Video Data Link
1.2. Reference Documents
Document Location
Mobile Intel
®
Pentium
®
4 Processor –M
Datasheet (250686), Mobile Intel Celeron®
processor(251308), Intel Celeron®
processor(290749)
http://developer.intel.com
Intel
®
Celeron
®
M Processor
Datasheet(300302) http://developer.intel.com
Intel
®
Celeron
®
D Processor on 90 nm Process
and in the 478-pin Package Datasheet http://developer.intel.com
PCI Local Bus Specification 2.2 www.pcisig.com
Intel
®
82801DBM I/O Controller Hub 4 Mobile
(ICH4-M) Datasheet (252337)
http://developer.intel.com/design/mobile/datashts/252337.htm
Mobile Intel
®
Pentium
®
4 Processor-M, Intel
®
Celeron
®
M Processor, Mobile Intel
®
Celeron
®
Processor, and Intel® 852GME, Intel® 852GMV
and Intel® 852PM Chipset Platforms Design
Guide(25302601)
http://developer.intel.com
Advanced Configuration and Power
Management(ACPI) Specification 1.0b & 2.0 http://www.teleport.com/~acpi/
Advanced Power Management (APM)
Specification 1.2 http://www.microsoft.com/hwdev/busbios/amp_12.htm
IA-32 Intel
®
Architecture Software Developer
Manual Volume 3: System Programming Guide http://developer.intel.com/design/Pentium4/manuals/24547203.pdf
Intel
®
Graphics Software PC 12.0 Product
Requirements Contact your Intel Field Representative
Common Panel Interface Specification Version
1.5 Contact your Intel Field Representative
Introduction
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Intel
®
852GM/852GMV Chipset GMCH Datasheet 21
1.3. System Architecture Overview
1.3.1. Intel 852GM GMCH System Architecture
The Intel 852GM GMCH component provides the processor interface, DDR SDRAM interface, display
interface, and Hub Interface in an Intel 852GM chipset platform. The Intel 852GM GMCH is optimized
for the Mobile Intel Pentium 4 Processor-M, Mobile Intel Celeron pro cessor and Intel Celeron M
processor. It supports a single channel of DDR SDRAM memory. Intel 852GM Chipset contains
advanced power management logic. The Intel 852GM Chipset platform supports the fourth generation
mobile I/O Controller Hub to provide the features required by a mobile platform.
The Intel 852GM GMCH is in a 732-pin Micro- FCBGA package and contains the following
functionality:
Supports single Intel processor configurations at 400-MHz or 3 GB/s
1.2-1.30-V AGTL+ host bus supporting 32-bit host bus addressing with Enhanced Intel
SpeedStep
®
technology (Intel Celeron M processor and In tel Celeron Processor do not support
Enhanced Intel SpeedStep Technology).
System Memory supports 200/266-MHz (SSTL_2) DDR DRAM
Up to 1 GB (with 256-Mb technology and two SO-DIMMs) of PC1600/2100 DDR SDRAM
without ECC
Integrated graphics capabilities, including 3D rendering acceleration and 2D hardware
acceleration
Integrated 350- M Hz, 24 -bit RAMDAC with pixel resolution up to 1600 x1200 at 85-Hz and up to
1920x1440 @ 60 Hz
One Dedicated Dual Channel LFP LVDS interface with freque ncy range of 25 MHz to 112 MHz
(single channel/dual channel) fo r sup p ort u p t o SXG A+ (1 4 00x1050 @ 60 Hz) panel res o l ut i ons
with maximum pixel depth of 18-bpp
Integrated PWM (Pulse Width Modulation) interface for LFP backlight inverter control for panel
brightness
One 165-MHz , 12-bit, DVO interface for TV-out encoder and DVI (LVDS transmitter and TMDS
transmitter) support
I2C and DDC channel s su pported
Dual Pipe Independent Display with Tri-view suppo rt through LFP, DVO, and CRT
Deeper Sleep state support
Distributed arbitration for highly concurrent operation
1.3.2. Intel 852GMV GMCH System Architecture
The Intel 852GMV GMCH component provides the processor interface, DDR SDRAM interface,
display interface, and Hub interface in an Intel 852GMV chipset platform. All features listed for Intel
852GM is supported for the Intel 852GMV. The GMCH is optimized for use with the Intel Celeron
processor. It supports a single channel of DDR SDRAM memory. The 852GMV GMCH contains
advanced power management logic. The Intel 852GMV chipset platform supports the fourth generation
mobile I/O Controller Hub (ICH4-M) to provide the features required by a mobile platform.
Introduction
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22 Intel
®
852GM/852GMV Chipset GMCH Data sheet
The Intel 852GMV GMCH is in a 732-pin Micro-FCBGA package and contain the following
functionality:
Supports a single Intel Celeron processor configuration at 400 MHz
Supports a single Intel Celeron D processor on 90 nm process and in the 478-pin package
configuration at 533 MHz
System SDRAM supports 200/266 MHz (SSTL_2) DDR SDRAM
Up to 1-GB (with 512 Mb technology and two SO-DIMMs) of PC1600/2100DDR SDRAM
without ECC
One 165-MHz , 12-bit, DVO interface for TV-out encoder and DVI (LVDS transmitter and TMDS
transmitter) support
Integrated 350-MHz, 24-bit RAMDAC with maximum pixel resolution support up to 1600x1200
at 85 Hz and up to 2048x1536 at 75 Hz
One Dedicated Dual Channel LFP LVDS interface with frequency range of 25 MHz to 112 MHz
(single channel/dual channel) fo r sup p ort u p t o UX GA (16 0 0 x 12 0 0 60 Hz ) panel resolutions
with maximum pixel depth of 18 bpp
Introduction
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Intel
®
852GM/852GMV Chipset GMCH Datasheet 23
1.4. Processor Host Interface
1.4.1. Intel 852GM GMCH Processor Host Interface
Mobile Intel Pentiu m 4 Proc essor-M key features include:
Source synchronous double pumped address (2X)
Source synchronous quad pumped data (4X)
System bus interrupt and side-band signal delivery
In this mode, Intel 852GM GMCH supports:
A 64B cache line size
A Front Side Bus freq uency o f 40 0-MHz (dual process or is not su p port e d )
AGTL+ termination resistors on all of the AGTL+ signals
32-bit host bus addressing allowing the CPU to access the entire 4 GB of the Intel 852GM GMCH
memory address space
Mobile Intel Celeron processor key features include:
Support for a 400-MHz Front Side Bus frequency
Source synchronous double pumped address (2X)
Source synchronous quad pumped data (4X)
System bus interrupt and side-band signal delivery
AGTL+ termination resistors on all of the AGTL+ signals
32-bit host bus addressing allowing the CPU to access the entire 4-GB of the memory address
space
Intel Celeron M processor key features include:
Support for a 400-MHz Front Side Bus frequency
Source synchronous double pumped address (2X)
Source synchronous quad pumped data (4X)
Front side bus inte rr upt del i very
Low voltage swing Vtt (1.05V)
Dynamic Power Down (DPWR#) support
Integrates AGTL+ termination resistors on all of the AGTL+ signals
Supports 32-bit host bus addressing allowing the CPU to access th e entire 4 GB of the GMCH
memory address space
An 8-deep, In-Order queue
Support DPWR# signal
Supports one outstanding defer cycle at a time to any particular I/O interface
Intel 852GM GM CH has an In -O rd er Q ueu e to support outsta ndi n g pipelined address re quests on the
host bus. Intel 852GM G MCH supports one outstanding defer cycle at a time; however, it supports only
one to any particular I/O interface. Host initiated I/O cycles are positively decoded to the Intel 852GM
GMCH configuration space and subtractively decoded to the Hub Interface. Host initiated memory
Introduction
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24 Intel
®
852GM/852GMV Chipset GMCH Data sheet
cycles are positively decoded to the DDR SDRAM. Memory accesses initiated from the Hub Interface to
DDR SDRAM will be snooped on the system bus.
1.4.2. Intel 852GMV GMCH Processor Host Interface
Intel Celeron pro cessor (400 MHz) and Intel Celeron D processor on 90 nm process and in the 478-pin
package (533 MHz) key features include:
Source synchronous double pumped address
Source synchronous quad pumped data
System bus interrupt and side-band signal delivery
AGTL+ termination resistors on all of the AGTL+ signals
32-bit host bus addressing allowing the CPU to access the entire 4-GB of the memory address
space
Intel 852GMV GMCH has an In -Order Queue to suppo rt up to twelve outstanding pipelined address
requests on the host bus. Int e l 85 2 GM V GMCH supports one outst anding defe r cycle at a time; however,
it supports only one to any particular I/O interface. Host initiated I/O cycles are positively decoded to the
Intel 852GMV GMCH configuration space and subtractively decoded to the Hub Interface. Host
initiated memory cycles are positively decoded to the DDR SDRAM. Memory accesses initiated from
the Hub Interface to DDR SDRAM will be snooped on the system bus.
1.5. Intel 852GM/852GMV GMCH Host Bus Error Checking
The Intel 852GM / 85 2GMV GMCH does not generat e no r c heck pari t y for Dat a, Ad d ress/Request, and
Response signals on the processor bus.
1.6. Intel 852GM/852GMV GMCH System Memory Interface
The Intel 852GM / 852GMV GMCH System Memory controller di rect ly supports the foll owing:
One channel of PC1600/2100 SO-DIMM DDR SDRA M memor y
DDR SDRAM devices with densities of 128-Mb, 256-Mb, and 512-Mb technology
Maximum system memory support of two, double-sided SO-DIMMs (four rows populated) with
up to 1 GB memory
Variable page sizes of 2-kB, 4-kB, 8-kB, and 16-kB. Page size is individually selected for every
row and a maximum of 16 pages may be opened simultaneously
Table 1. DDR Memory Capacity
Technology Width System Memory Capacity
128 Mb 8 256 MB
256 Mb 8 512 MB
512 Mb 8 1 GB
128 Mb 16 256 MB
Introduction
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Intel
®
852GM/852GMV Chipset GMCH Datasheet 25
Technology Width System Memory Capacity
256 Mb 16 512 MB
512 Mb 16 1 GB
The Intel 852GM/852GMV GMCH System Memory interface supports a thermal throttling scheme to
selectively throttle reads and/or writes. Throttling can be triggered either by on-die thermal sensor, or by
preset write bandwidth limits. Read throttle can also be triggered by an external input pin. The memory
controller logic supports aggressive dynamic row power down features (SCKE) to help reduce power
and supports Address and Control lines Tri-statin g when DDR SDRAM is in active power down or self
refresh.
The Intel 852GM/852GMV GMCH System Memory architecture is optimized to maintain open pages
(up to 16-kB page size) across multiple rows. As a result, up to 16 pages across four rows. To
complement this, the GMCH will tend to keep pages open within rows, or will only clos e a single bank
on a page miss. Intel 852GM/852GMV GMCH supports only two bank memory technologies.
1.7. Intel 852GM/852GMV GMCH Internal Graphics
The GMCH IGD provides a highly integrated graphics accelerator delivering high performance 3D, 2D,
and video capabilities. With its interfaces to UMA using a DVMT configuration, analog display, LVDS,
and digital display (e.g. flat pane l), the GMCH provides a complete graphics so lution. The GMCH
contains an extens ive set of instructions for the following:
The GMCH also provides 2D hardware acceleration for block transfers of data (BLTs). The BLT engine
provides the ability to copy a source blo ck of data to a d e stinatio n and perform raster operations (e.g.,
ROP1, ROP2, and ROP3) on the data using a pattern, and/or another destination. Performing these
common tasks in hardware reduces CPU load, and thus improves performance.
High bandwidth access to data is provided through the System Memory ports. The GMCH uses Tiling
architecture to increase System Memory efficiency and thus maximize effective rendering bandwidth.
The Intel 852GM/852GMV GMCH has three display ports, one analog and two digital. These provide
support for a progressive scan analog monitor, a dedicated dual channel LVDS panel and a DVO device.
Each port can transmit data according to one or more protocols. The DVO port is connected to an
external device that converts one protocol to another. Examples of this are TV-out encoders, external
DACs, LVDS transmitters, and TMDS transmitters. Each display port has control signals that may be
used to control, configu re and/or determine the capabilities of an external device. The data that is sent
out the display port is selected from one of the two possible sources, pipe A or pipe B.
1.7.1. Intel 852GM/852GMV GMCH Analog Display Port
Intel 852GM/852GMV GMCH has an integrated 350-MHz, 24-b it RAMDAC that can directly drive a
progressive scan analog monitor pixel r e solution up to 1600x1200 at 85-Hz refresh an d up to 1920x1440
at 60-Hz refresh. The DAC port can be driven on Pipe A or Pipe B.
1.7.2. Intel 852GM/852GMV GMCH Integrated LVDS Port
The Intel 852GM/852GMV GMCH has an integrated dual channel LFP Transmitter interface to support
LVDS LCD panel resolutions up to SXGA+ with center and down spread SSC support of 0.5%, 1%, and
2.5% utilizing an external SSC clock. The display pipe provides p anel up-scalin g to fit a source image
Introduction
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26 Intel
®
852GM/852GMV Chipset GMCH Data sheet
into a specific panel size as well as panning and centering support. The LVDS port is only suppo rted on
Pipe B. The LVDS port can only be driven on Pipe B, either independently or simultaneously with the
DAC port .
1.7.3. Intel 852GM/852GMV GMCH Integrated DVO Port
The DVO C interface is compliant with the DVI Specification 1.0. When com bined wit h a DVI
compliant external device (e.g. TMDS Flat Panel Transmitter, TV-out encoder, etc.), the GMCH
provides a high-speed interface to a digital or analog display (e.g. flat panel, TV monitor, etc.).
Intel 852GM/852GMV GMCH provides a DVO port that is capable of driving a 165-MHz pixel clock at
the DVO C interface. The DVO C port can be driven on Pipe A or Pipe B. If driven on port B, then the
LVDS port must be disabl ed.
1.8. Hub Interface
A proprietary interconnect connects the GMCH to the ICH4-M Chipset. All communication betw een the
GMCH and the ICH4-M occurs over the Hub Interface. The Hub Interface runs at 66- MHz or 266-
MB/s.
1.9. Address Decode Policies
Host initiated I/O cycles are positively decoded to the GMCH configuration space and subtractively
decoded to Hub Interface. Host initiated System Memory cycles are positively decoded to DDR
SDRAM and are again subtractively decoded to Hub Interface if under 4 GB. System Memory accesses
from Hub Interface to DDR SDRAM will be snooped on the FSB.
1.10. Intel 852GM/852GMV GMCH Clocking
The GMCH has the following clock input/output pins:
400 MHz, Spread Spectrum, Low Voltage (1.3 V) Differential BCLK, BCLK# for Processor
System Bus
66-MHz Spread Spectrum , 3.3-V GCLKIN for Hub Interface buffers
Four pairs of di fferential outp ut clocks (SCK[4,3 ,1:0], SCK[4 ,3 ,1:0]#), 200/ 2 66 MHz, 2.5 V for
System Memory interface
48-MHz, non-Spread Spectrum, 3.3-V DREFCLK for the Display Frequency Synthesis
48-MHz or 66-MHz, Spread Spectrum, 3.3-V DREFSSCLK for the Display Frequency Synthesis
Up to 85-MHz, 1.5 -V DVOBCCLKINT for TV- O ut mode
DPMS clock for S1-M
Clock Synthesizer chip(s) are responsible for generating the system host clocks, display and Hub
Interface clocks, PCI clocks, and System Memory clocks. The host target speed is 400 MHz. The
GMCH does not require any relationship between the BCLK host clock and the 66-MHz clock generated
for Hub Interface; they are asynchronous from each other. The Hub Interface runs at a constant 66-MHz
base frequency. Table 2 indicates the frequ enc y ratios between the various interfaces that the GMCH
supports.
Please see Section 5.5.2.7 for details on the Intel 852GM/852GMV GMCH SSC Usage Model.
Introduction
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Intel
®
852GM/852GMV Chipset GMCH Datasheet 27
Table 2. Intel 852GM/852GMV GMCH Interface Clocks
Interface Clock Speed CPU System Bus
Frequency Ratio Samples
Per Clock Data Rate
(Mega-
samples/s)
Data
Width
(Bytes)
Peak
Bandwidth
(MB/s)
CPU Bus 100 MHz Reference 4 400 8 3200
CPU Bus
(852GMV Only)
133 MHz Reference 4 533 8 4264
100 MHz 1:1 Synchronous 2 200 8 1600
DDR SDRAM 133 MHz 1:1 Synchronous 2 266 8 2128
LVDS Flat Panel 25 MHz-112 MHz
(single channel)
Asynchronous 1 112 2.25 252
DVO C Up to 165 MHz Asynchronous 2 330 1.5 495
DAC Interface 350 MHz Asynchronous 1 350 3 1050
1.11. System Interrupts
The Intel 852GM/852GMV GMCH supports both the leg acy Intel 8259 Programmable Interrupt
delivery mechanism and the processor side bus interrupt delivery mechanism. The serial APIC Interrupt
mechanism is not supported.
The Intel 8259 Interrupt delivery mechanism support consists of flushing in bound Hub Interface write
buffers when an Interrupt Acknowledge cycle is forwarded from the system bus to the Hub Interface.
PCI MSI interrupts are generated as Memory Writes. The GMCH decodes upstream Memory Writes to
the range 0FEE0_0000h - 0FEEF_FFFFh from the Hub Interface as message based interrupts. The
GMCH forwards the Memory Writes along with the associated write data to the system bus as an
Interrupt Message transaction. Since this address does not decode as part of main System Memory, the
write cycle and the write data does not get forwarded to System Memory via the write buffer. The
GMCH provides the response and HTRDY# for all Interrupt Message cycles including the ones
originating from the GMCH. The GMCH also supports interrupt re-direction for upstream interrupt
memory writes.
For message based interrupts, system write buffer coherency is maintained by relying on strict ordering
of Memory Writes. The GMCH ensures that all Memory Writes received from a given interface prior to
an interrupt message Memory Write are delivered to the system bus for snooping in the same order that
they occur on the given interface.
Introduction
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Signal Description
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2. Signal Description
This section describes the GMCH signals. These signals are arranged in functional groups according to
their associated interface. The following notations are used to describe the signal type:
I Input pin
O Output pin
I/O Bi-directional Input/Output pin
The signal description also includes the type of buffer used for the particular signal:
AGTL+ Open Drain GTL+ interface signal. Refer to the GTL+ I/O Specification for complete details.
The GMCH integrates AGTL+ termination resistors, and supports V
tt
of 1.2-1.30 V ± 5%.
AGTL+ signals are “inverted bus” style where a low voltage represents a logical “1”.
DVO DVO buffers. These are 1.5-V tolerant
1.5 V 1.5-V compatible DC and AC Specification voltage levels
SSTL_2 Stub Series Termination Logic compatible signals. These are 2.5-V tolerant.
LVTTL Low Voltage TTL compatible signals. These are 3.3-V tolerant.
CMOS CMOS buffers. These are 3.3-V tolerant
LVDS Low Voltage Differential signal interface
Analog Analog signal interface
Ref Voltage reference signal
Note: System address and data bus signals are logically inverted signals. In other words, the actual values are
inverted of what appears on the system bus. This must be taken into account and the addresses and data
bus signals must be inverted inside the GMCH. All processor control signals follow normal convention.
A “0” indicates an active level (low voltage), and a “1” indicates an active level (high voltage).
Signal Description
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30 Intel
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2.1. Host Interface Signals
Table 3. Host Interface Signal Descriptions
Signal Name Type Description
ADS# I/O
AGTL+
Address Strobe: The system bus owner asserts ADS# to indicate the first of two
cycles of a request phase. The GMCH can assert this signal for snoop cycles and
interrupt messages.
BNR# I/O
AGTL+
Block Next Request: Used to block the current request bus owner from issuing a
new request. This signal is used to dynamically control the CPU bus pipeline depth.
BPRI# O
AGTL+
Bus Priority Request: The GMCH is the only Priority Agent on the system bus. It
asserts this signal to obtain the ownership of the address bus. This signal has
priority over symmetric bus requests and will cause the current symmetric owner to
stop issuing new transactions unless the HLOCK# signal was asserted.
BREQ0# I/O
AGTL+
Bus Request 0B: The GMCH pulls the processor bus BREQ0# signal low during
CPURST#. The signal is sampled by the processor on the active-to-inactive
transition of CPURST#. The minimum setup time for this signal is 4 BCLKs. The
minimum hold time is 2 clocks and the maximum hold time is 20 BCLKs. BREQ0#
should be tristated after the hold time requirement has been satisfied.
During regular operation, the GMCH will use BREQ0# as an early indication for
FSB Address and Ctl input buffer and sense amp activation.
CPURST# O
AGTL+
CPU Reset: The CPURST# pin is an output from the GMCH. The GMCH asserts
CPURST# while RESET# (PCIRSTB# from ICH4-M) is asserted and for
approximately 1 ms after RESET# is deasserted. The CPURST# allows the
processor to begin execution in a known state.
Note that the ICH4-M must provide CPU strap set-up and hold-times around
CPURST#. This requires strict synchronization between GMCH, CPURST#
deassertion and ICH4-M driving the straps.
DBSY# I/O
AGTL+
Data Bus Busy: Used by the data bus owner to hold the data bus for transfers
requiring more than one cycle.
DEFER# O
AGTL+
Defer: GMCH will generate a deferred response as defined by the rules of the
GMCH’s dynamic defer policy. The GMCH will also use the DEFER# signal to
indicate a CPU retry response.
DINV[3:0]# I/O
AGTL+
Dynamic Bus Inversion: Driven along with the HD[63:0]# signals. Indicates if the
associated signals are inverted or not. DINV[3:0]# are asserted such that the
number of data bits driven electrically low (low voltage) within the corresponding 16-
bit group never exceeds 8.
DINV# Data Bits
DINV[3]# HD[63:48]#
DINV[2]# HD[47:32]#
DINV[1]# HD[31:16]#
DINV[0]# HD[16:0]#
DPSLP# I
CMOS
Deep Sleep: This signal comes from the ICH4-M device, providing an indication of
C3 and C4 state control to the CPU. Negation of this signal is used as an early
indication for C3 and C4 wake up (to active HPLL). Note that this is a low-voltage
CMOS buffer operating on the FSB VTT power plane.
DPWR# O
AGTL+
Data Power: Asserted by GMCH to indicate that a data return cycle is pending
within 2 HCLK cycles or more.
CPU should use this signal during a read-cycle to activate the data input buffers
and sense-amps in preparation for DRDY# and the related data.
Signal Description
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Signal Name Type Description
DRDY# I/O
AGTL+
Data Ready: Asserted for each cycle that data is transferred.
HA[31:3]# I/O
AGTL+
Host Address Bus: HA[31:3]# connects to the CPU address bus. During
processor cycles the HA[31:3]# are inputs. The GMCH drives HA[31:3]# during
snoop cycles on behalf of Hub Interface. HA[31:3]# are transferred at 2x rate. Note
that the address is inverted on the CPU bus.
HADSTB[1:0]# I/O
AGTL+
Host Address Strobe: HA[31:3]# connects to the CPU address bus. During CPU
cycles, the source synchronous strobes are used to transfer HA[31:3]# and
HREQ[4:0]# at the 2x transfer rate.
Strobe Address Bits
HADSTB[0]# HA[16:3]#, HREQ[4:0]#
HADSTB[1]# HA[31:17]#
HD[63:0]# I/O
AGTL+
Host Data: These signals are connected to the CPU data bus. HD[63:0]# are
transferred at 4x rate. Note that the data signals are inverted on the CPU bus.
HDSTBP[3:0]#
HDSTBN[3:0]#
I/O
AGTL+
Differential Host Data Strobes: The differential source synchronous strobes are
used to transfer HD[63:0]# and DINV[3:0]# at the 4x transfer rate.
Strobe Data Bits
HDSTBP[3]#, HDSTBN[3]# HD[63:48]#, DINV[3]#
HDSTBP[2]#, HDSTBN[2]# HD[47:32]#, DINV[2]#
HDSTBP[1]#, HDSTBN[1]# HD[31:16]#, DINV[1]#
HDSTBP[0]#, HDSTBN [0]# HD[15:0]#, DINV[0]#
HIT# I/O
AGTL+
Hit: Indicates that a caching agent holds an unmodified version of the requested
line. Also, driven in conjunction with HITM# by the target to extend the snoop
window.
HITM# I/O
AGTL+
Hit Modified: Indicates that a caching agent holds a modified version of the
requested line and that this agent assumes responsibility for providing the line.
Also, driven in conjunction with HIT# to extend the snoop window.
HLOCK# I/O
AGTL+
Host Lock: All CPU bus cycles sampled with the assertion of HLOCK# and ADS#,
until the negation of HLOCK# must be atomic, i.e. no Hub Interface snoopable
access to DRAM are allowed when HLOCK# is asserted by the CPU.
HREQ[4:0]# I/O
AGTL+
Host Request Command: Defines the attributes of the request. HREQ[4:0]# are
transferred at 2x rate. Asserted by the requesting agent during both halves of
Request Phase. In the first half the signals define the transaction type to a level of
detail that is sufficient to begin a snoop request. In the second half the signals carry
additional information to define the complete transaction type.
The transactions supported by the GMCH Host Bridge are defined in the Host
Interface section of this document.
HTRDY# O
AGTL+
Host Target Ready: Indicates that the target of the processor transaction is able to
enter the data transfer phase.
Signal Description
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Signal Name Type Description
RS[2:0]# O
AGTL+
Response Status: Indicates type of response according to the following the table:
RS[2:0]# Response type
000 Idle state
001 Retry response
010 Deferred response
011 Reserved (not driven by GMCH)
100 Hard Failure (not driven by GMCH)
101 No data response
110 Implicit Write back
111 Normal data response
Signal Description
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2.2. DDR SDRAM Interface
Table 4. DDR SDRAM Interface Descriptions
Signal Name Type Description
SCS[3:0]# O
SSTL_2
Chip Select: These pins select the particular DDR SDRAM components during the
active state.
NOTE: There is one SCS# per DDR-SDRAM Physical SO-DIMM device row. These
signals can be toggled on every rising System Memory Clock edge (SCMDCLK).
SMA[12:0] O
SSTL_2
Multiplexed Memory Address: These signals are used to provide the multiplexed
row and column address to DDR SDRAM.
SBA[1:0] O
SSTL_2
Bank Select (Memory Bank Address): These signals define which banks are
selected within each DDR SDRAM row. The SMA and SBA signals combine to
address every possible location within a DDR SDRAM device.
SRAS# O
SSTL_2
DDR Row Address Strobe: SRAS# may be heavily loaded and requires 2 DDR
SDRAM clock cycles for setup time to the DDR SDRAMs. Used with SCAS# and
SWE# (along with SCS#) to define the System Memory commands.
SCAS# O
SSTL_
DDR Column Address Strobe: SCAS# may be heavily loaded and requires 2 DDR
clock cycles for setup time to the DDR SDRAMs. Used with SRAS# and SWE#
(along with SCS#) to define the System Memory commands.
SWE# O
SSTL_2
Write Enable: Used with SCAS# and SRAS# (along with SCS#) to define the DDR
SDRAM commands. SWE# is asserted during writes to DDR SDRAM. SWE# may
be heavily loaded and requires two DDR SDRAM clock cycles for setup time to the
DDR SDRAMs.
SDQ[71:0] I/O
SSTL_2
Data Lines: These signals are used to interface to the DDR SDRAM data bus.
NOTE: ECC error detection is NOT supported: SDQ[71:64] signals should be left as
NC (“No Connect”) on Intel 852GM/852GMV GMCH.
SDQS[8:0]
I/O
SSTL_2
Data Strobes: Data strobes are used for capturing data. During writes, SDQS is
centered in data. During reads, SDQS is edge aligned with data. The following list
matches the data strobe with the data bytes.
There is an associated da ta strobe (DQS) for each data strobe (DQ) and check
bit (CB) group.
SDQS[7] -> SDQ[63:56]
SDQS[6] -> SDQ[55:48]
SDQS[5] -> SDQ[47:40]
SDQS[4] -> SDQ[39:32]
SDQS[3] -> SDQ[31:24]
SDQS[2] -> SDQ[23:16]
SDQS[1] -> SDQ[15:8]
SDQS[0] -> SDQ[7:0]
NOTE: ECC error detection is NOT supported: SDQS[8] signal should be left as NC
(“No Connect”) on the Intel 852GM/852GMV GMCH.
SCKE[3:0] O
SSTL_2
Clock Enable: These pins are used to signal a self-refresh or power down command
to a DDR SDRAM array when entering system suspend. SCKE is also used to
dynamically power down inactive DDR SDRAM rows. There is one SCKE per DDR
SDRAM row. These signals can be toggled on every rising SCK edge.
Signal Description
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Signal Name Type Description
SMAB[5,4,2,1] O
SSTL_2
Memory Address Copies: These signals are identical to SMA[5,4,2,1] and are used
to reduce loading for selective CPC(clock-per-command). These copies are not
inverted.
SDM[8:0] O
SSTL_2
Data Mask: When activated during writes, the corresponding data groups in the
DDR SDRAM are masked. There is one SDM for every eight data lines. SDM can be
sampled on both edges of the data strobes.
NOTE: ECC error detection is NOT supported: SDM[8] signal should be left as NC
(“No Connect”) on the Intel 852GM/852GMV GMCH.
RCVENOUT# O
SSTL_2
Clock Output: Used to emulate source-synch clocking for reads. This pin is a NC.
RCVENIN# O
SSTL_2
Clock Input: Used to emulate source-synch clocking for reads. This is pin is a NC.
2.3. Hub Interface Signals
Table 5. Hub Interface Signals
Signal Name Type Description
HL[10:0] I/O
1.5
Packet Data: Data signals used for HI read and write operations.
HLSTB I/O
1.5
Packet Strobe: One of two differential strobe signals used to transmit or receive
packet data over HI.
HLSTB# I/O
1.5
Packet Strobe Complement: One of two differential strobe signals used to transmit
or receive packet data over HI.
Signal Description
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2.4. Clocks
Table 6. Clock Signals
Signal Name Type Description
Host Processor Clocking
BCLK
BCLK#
I
CMOS
Differential Host Clock In: These pins receive a buffered host clock from the
external clock synthesizer. This clock is used by all of the GMCH logic that is in the
Host clock domain (host, Hub and System Memory). The clock is also the
reference clock for the graphics core PLL. This is a low voltage differential input.
System Memory Clocking
SCK[5:0] O
SSTL_2
Differential DDR Clock: SCK and SCK# pairs are differential clock outputs. The
crossing of the positive edge of SCK and the negative edge of SCK# is used to
sample the address and control signals on the DDR SDRAM. There are 3 pairs to
each SO-DIMM.
NOTE: ECC error detection is NOT supported: SCK[2], SCK[5] signals should be
left as NC (“No Connect”) on the Intel 852GM/852GMV GMCH.
SCK[5:0]# O
SSTL_2
Complementary Differential DDR Clock: These are the complimentary
differential DDR SDRAM clock signals.
NOTE: ECC error detection is NOT supported: SCK[2]#, SCK[5]# signals should
be left as NC (“No Connect”) on the Intel 852GM/852GMV GMCH.
DVO/Hub Input Clocking
GCLKIN I
CMOS
Input Clock: 66-MHz, 3.3-V input clock from external buffer DVO/Hub Interface.
DVO Clocking
DVOCCLK
DVOCCLK#
O
DVO
Differential DVO Clock Output: These pins provide a differential pair reference
clock that can run up to 165 MHz.
DVOCCLK corresponds to the primary clock out.
DVOCCLK# corresponds to the primary complementary clock out.
DVOCCLK and DVOCCLK# should be left as NC (“Not Connected”) if the DVO C
port is not implemented.
DVOBCCLKINT I
DVO
DVOBC Pixel Clock Input/Interrupt: This signal may be selected as the reference
input to either dot clock PLL (DPLL) or may be configured as an interrupt input. A
TV-out device can provide the clock reference. The maximum input frequency for
this signal is 85 MHz.
DVOBC Pixel Clock Input: When selected as the dot clock PLL (DPLL) reference
input, this clock reference input supports SSC clocking for DVO LVDS devices.
DVOBC Interrupt: When configured as an interrupt input, this interrupt can support
for either of the DVOB or DVOC.
DVOBCCLKINT needs to be pulled down if the signal is NOT used.
DPMS I
DVO
Display Power Management Signaling: This signal is used only in mobile
systems to act as the DREFCLK in certain power management states(i.e. display
power down mode); DPMS Clock is used to refresh video during S1-M. Clock Chip
is powered down in S1-M. DPMS should come from a clock source that runs during
S1-M and needs to be 1.5 V. So, an example would be to use a 1.5-V version of
SUSCLK from ICH4-M.
DAC Clocking
Signal Description
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Signal Name Type Description
DREFCLK I
LVTTL
Display Clock Input: This pin is used to provide a 48-MHz input clock to the
Display PLL that is used for 2D/Video and DAC.
LFP LVDS Clocking
DREFSSCLK I
LVTTL
Display SSC Clock Input: This pin provides a 48-MHz or 66-MHz input clock
(SSC or non-SSC) to the Display PLL B.
Signal Description
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2.5. Internal Graphics Display Signals
The internal graphics device has support for a dedicated LFP LVDS interface, DVOC interface, and an
analog VGA port.
2.5.1. Dedicated LFP LVDS Interface
Table 7. Dedicated LVDS Flat Panel Interface Signal Descriptions
Name Type Voltage Description
ICLKAP O
LVDS
1.25 V± 225 mV Channel A differential clock pair output (true): 245-800 MHz
ICLKAM O
LVDS
1.25 V±225 mV Channel A differential clock pair output (compliment): 245-
800 MHz.
IYAP[3:0] O
LVDS
1.25 V±225 mV Channel A differential data pair 3:0 output (true): 245-800
MHz.
IYAM[3:0] O
LVDS
1.25 V±225 mV Channel A differential data pair 3:0 output (compliment): 245-
800 MHz.
ICLKBP O
LVDS
1.25 V±225 mV Channel B differential clock pair output (true): 245-800 MHz.
ICLKBM O
LVDS
1.25 V±225 mV Channel B differential clock pair output (compliment): 245-
800 MHz.
IYBP[3:0] O
LVDS
1.25 V±225 mV Channel B differential data pair 3:0 output (true): 245-800
MHz.
IYBM[3:0] O
LVDS
1.25 V± 225 mV Channel B differential data pair 3:0 output (compliment): 245-
800 MHz.
Signal Description
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2.5.2. Digital Video Port C (DVOC)
Table 8. Digital Video Port C (DVOC) Signal Descriptions
Name Type Description
DVOCD[11:0] O
DVO
DVOC Data: This data bus is used to drive 12-bit RGB data on each edge of the
differential clock signals, DVOCCLK and DVOCCLK#. This provides 24-bits of data
per clock period. In dual channel mode, this provides the upper 12-bits of pixel data.
DVOCD[11:0] should be left as left as NC (“Not Connected”) if not used.
DVOCHSYNC O
DVO
Horizontal Sync: HSYNC signal for the DVOC interface.
DVOCHSYNC should be left as left as NC (“Not Connected”) if not used.
DVOCVSYNC O
DVO
Vertical Sync: VSYNC signal for the DVOC interface.
DVOCVSYNC should be left as left as NC (“Not Connected”) if the signal is NOT
used when using internal graphics device.
DVOCBLANK# O
DVO
Flicker Blank or Border Period Indication: DVOCBLANK# is a programmable
output pin driven by the Intel 852GM/852GMV GMCH.
When programmed as a blank period indication, this pin indicates active pixels
excluding the border. When programmed as a border period indication, this pin
indicates active pixel including the border pixels.
DVOCBLANK# should be left as left as NC (“Not Connected”) if not used.
DVOBCINTR# I
DVO
DVOBC Interrupt: This pin is used to signal an interrupt, typically used to indicate a
hot plug or unplug of a digital display.
DVOCFLDSTL I
DVO
TV Field and Flat Panel Stall Signal. This input can be programmed to be either
a TV Field input from the TV encoder or Stall input from the flat panel.
DVOC TV Field Signal: When used as a Field input, it synchronizes the overlay
field with the TV encoder field when the overlay is displaying an interleaved source.
DVOC Flat Panel Stall Signal: When used as the Stall input, it indicates that the
pixel pipeline should stall one horizontal line. The signal changes during horizontal
blanking. The panel fitting logic, when expanding the image vertically, uses this.
DVOCFLDSTL needs to be pulled down if not used.
ADDID[7:0] I
DVO
ADDID[7:0]: These pins are used to communicate to the Video BIOS when an
external device is interfaced to the DVO port.
Note: Bit[7] needs to be strapped low when a DVO device is present. The other
pins should be left as NC.
DVODETECT I
DVO
DVODETECT: This strapping signal indicates to the GMCH whether a DVO device
is plugged in or not. When a DVO device is connected, then DVODETECT = 0.
Signal Description
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2.5.3. Analog Display
Table 9. Analog Display Signal Descriptions
Pin
Name Type Description
VSYNC O
CMOS
CRT Vertical Synchronization: This signal is used as the vertical sync signal. Refer to
Table 36.
HSYNC O
CMOS
CRT Horizontal Synchronization: This signal is used as the horizontal sync signal. Refer
to Table 36.
RED O
Analog
Red (Analog Video Output): This signal is a CRT Analog video output from the internal
color palette DAC. The DAC is designed for a 37.5-Ω equivalent load on each pin (e.g.,
75-Ω resistor on the board, in parallel with the 75-Ω CRT load).
RED# O
Analog
Red# (Analog Output): Tied to ground.
GREEN O
Analog
Green (Analog Video Output): This signal is a CRT analog video output from the internal
color palette DAC. The DAC is designed for a 37.5-Ω equivalent load on each pin (e.g.,
75-Ω resistor on the board, in parallel with the 75- Ω CRT load).
GREEN# O
Analog
Green# (Analog Output): Tied to ground.
BLUE O
Analog
Blue (Analog Video Output) : This signal is a CRT Analog video output from the internal
color palette DAC. The DAC is designed for a 37.5-Ω equivalent load on each pin (e.g., 75-
ohm resistor on the board, in parallel with the 75-Ω (CRT load).
BLUE# O
Analog
Blue# (Analog Output): Tied to ground.
Signal Description
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40 Intel
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2.5.4. General Purpose Input/Output Signals
Table 10. Intel 852GM/852GMV GMCH GPIO (DDC, I2C, etc.) Signal Descriptions
GPIO I/F Total Type Comments
RSTIN# I
CMOS
Reset: Primary Reset
PWROK I
CMOS
Power OK: Indicates that power to GMCH is stable.
AGPBUSY# O
CMOS
AGPBUSY: Output of the GMCH graphics controller to the ICH4-M, which indicates that
certain graphics activity is taking place. It will indicate to the ACPI software to not enter the
C3 state. It will also cause a C3/C4 exit if C3/C4 was being entered, or was already entered
when AGPBUSY# went active. Not active when the graphics controller is in any ACPI state
other than D0.
EXTTS_0 I
CMOS
External Thermal Sensor Input: This signal is an active low input to the GMCH and is
used to monitor the thermal condition around the System Memory and is used for triggering
a read throttle. The GMCH can be optionally programmed to send a SERR, SCI, or SMI
message to the ICH4-M upon the triggering of this signal.
LCLKCTLA O
CMOS
SSC Chip Clock Control: Can be used to control an external clock chip with SSC control.
LCLKCTLB O
CMOS
SSC Chip Data Control: Can be used to control an external clock chip for SSC control.
PANELVDDEN O
CMOS
LVDS Panel power control: This signal is used enable power to the panel interface.
PANELBKLTEN O
CMOS
LVDS Panel backlight enable: This signal is used to enable the back light inverter(BLI).
PANELBKLTCTL O
CMOS
LVDS Panel backlight brightness control: This signal is used as power control.
DDCACLK I/O
CMOS
CRT DDC Clock: This signal is used as the DDC clock signal between the CRT monitor
and the GMCH.
DDCADATA I/O
CMOS
CRT DDC Data: This signal is used as the DDC data signal between the CRT monitor and
the GMCH.
DDCPCLK I/O
CMOS
Panel DDC Clock: This signal is used as the DDC clock signal between the LFP and the
GMCH.
DDCPDATA I/O
CMOS
Panel DDC Data: This signal is used as the DDC data signal between the LFP and the
GMCH.
MI2CCLK I/O
DVO
DVO I2C Clock: The specific function is I2C_CLK for a digital display (i.e. TV-Out Encoder,
TMDS transmitter). This signal is tri-stated during a hard reset.
MI2CDATA I/O
DVO
DVO I2C Data: The specific function is I2C_DATA for a digital display (i.e. TV-Out Encoder,
TMDS transmitter). This signal is tri-stated during a hard reset.
MDVICLK I/O
DVO
DVI DDC Clock: The specific function is DDC clock for a digital display connector (i.e.
primary digital monitor). This signal is tri-stated during a hard reset.
MDVIDATA I/O DVI DDC Data: The specific function is DDC data for a digital display connector (i.e.
Signal Description
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GPIO I/F Total Type Comments
DVO primary digital monitor). This signal is tri-stated during a hard reset.
MDDCDATA I/O
DVO
DVI DDC Clock: The specific function is DDC data for a digital display connector (i.e.
secondary digital monitor). This signal is tri-stated during a hard reset.
MDDCCLK I/O
DVO
DVI DDC Data: The specific function is DDC clock for a digital display connector (i.e.
secondary digital monitor). This signal is tri-stated during a hard reset.
Signal Description
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42 Intel
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2.6. Voltage References, PLL Power
Table 11. Voltage References, PLL Power
Signal Name Type Description
Host Processor
HXRCOMP Analog Host RCOMP: Used to calibrate the host AGTL+ I/O buffers.
HYRCOMP Analog Host RCOMP: Used to calibrate the host AGTL+ I/O buffers.
HXSWING Analog Host Voltage Swing (RCOMP reference voltage): These signals provide a
reference voltage used by the FSB RCOMP circuit.
HYSWING Analog Host Voltage Swing (RCOMP reference voltage): These signals provide a
reference voltage used by the FSB RCOMP circuit.
HDVREF[2:0] Ref
Analog
Host Data (input buffer) VREF: Reference voltage input for the data signals of the
host AGTL+ interface. Input buffer differential amplifier to determine a high versus
low input voltage.
HAVREF Ref
Analog
Host Address input buffer VREF: Reference voltage input for the address signals
of the host AGTL+ interface. This signal is connected to the input buffer differential
amplifier to determine a high versus low input voltage.
HCCVREF Ref
Analog
Host Common Clock (Comman d input buffer) VREF: Reference voltage input for
the common clock signals of the host AGTL+ interface. This signal is connected to
the input buffer differential amplifier to determine a high versus low input voltage.
VTTLF Power FSB Power Supply: VTTLF is the low frequency connection from the board. This
signal is the primary connection of power for GMCH.
VTTHF Power FSB Power Supply: VTTHF is the high frequency supply. It is for direct connection
from an internal package plane to a capacitor placed immediately adjacent to the
GMCH.
Note: Not to be connected to power rail.
System Memory
SMRCOMP Analog System Memory RCOMP: This signal is used to calibrate the memory I/O buffers.
SMVREF_0 Ref
Analog
Memory Reference Voltage(In put buffer VREF):Reference voltage input for
memory interface.
Input buffer differential amplifier to determine a high versus low input voltage.
SMVSWINGH Ref
Analog
RCOMP reference voltage: This is connected to the RCOMP buffer differential
amplifier and is used to calibrate the I/O buffers.
SMVSWINGL Ref
Analog
RCOMP reference voltage: This is connected to the RCOMP buffer differential
amplifier and is used to calibrate the I/O buffers.
VCCSM Power Power supply for Memory I/O.
VCCQSM Power Power supply for System Memory clock buffers.
VCCASM Power Power supply for System Memory logic running at the core voltage (isolated supply,
not connected to the core).
Hub Interface
HLRCOMP Analog Hub Interface RCOMP: This signal is connected to a reference resistor in order to
calibrate the buffers.
PSWING Analog RCOMP reference voltage: This is connected to the RCOMP buffer differential
amplifier and is used to calibrate the buffers.
Signal Description
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852GM/852GMV Chipset GMCH Datasheet 43
Signal Name Type Description
HLVREF Ref
Analog
Input buffer VREF: Input buffer differential amplifier to determine a high versus low
input voltage.
VCCHL Power Power supply for Hub Interface buffers
DVO
DVORCOMP Analog
Analog
Compensation for DVO: This signal is used to calibrate the DVO I/O buffers.
GVREF Ref
Analog
Input buffer VREF: Input buffer differential amplifier to determine a high versus low
input voltage.
VCCDVO Power Power supply for DVO.
GPIO
VCCGPIO Power Power supply for GPIO buffers
DAC
REFSET Ref
Analog
Resistor Set: Set point resistor for the internal color palette DAC.
VCCADAC Power Power supply for the DAC
VSSADAC Power Ground supply for the DAC
LVDS
LIBG Analog LVDS reference current: signal connected to reference resistor.
VCCDLVDS Power Digital power supply.
VCCTXLVDS Power Data/Clk Tx power supply.
VCCALVDS Power Analog power supply.
VSSALVDS Power Ground supply for LVDS.
Clocks
VCCAHPLL Power Power supply for the Host PLL.
VCCAGPLL Power Power supply for the Hub/DVO PLL.
VCCADPLLA Power Power supply for the display PLL A.
VCCADPLLB Power Power supply for the display PLL B.
Core
VCC Power Power supply for the core.
VSS Power Ground supply for the chip.
Signal Description
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Register Description
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852GM/852GMV Chipset GMCH Datasheet 45
3. Register Description
3.1. Conceptual Overview of the Platform Configuration
Structure
The Intel 852GM/852GMV GMCH and ICH4-M are physically connected by Hub Interface A. From a
configuration standpoint, the Hub Interface A is logically PCI bus #0. As a result, all devices internal to
the GMCH and ICH4 -M appear to be on PCI bus #0. The system’s primary PCI expansion bus is
physically attached to the ICH4-M and from a configuration perspective, appears to be a hierarchical
PCI bus behind a PCI-to-PCI bridge and therefore has a programmable PCI Bus number. Note that the
primary PCI bus is referred to as PCI_A in this document and is not PCI bus #0 from a configuration
standpoint.
The GMCH contains two PCI devices within a single physical component. The configuration registers
for the two devices are mapped as devices residing on PCI bus #0.
Device #0: Host-Hub Interface Bridge/DDR SDRAM Controller. Logically this appears as a PCI device
residing on PCI bus #0. Physically, Device 0 contains the standard PCI registers, DDR SDRAM
registers, the Graphics Aperture controller, HI control and other GMCH specific registers. Device 0 is
divided into functions as follows:
Function #0: Host Bridge Legacy Registers, including Graphics Aperture control, HI configuration and
Interrupt control registers
Function #1: DDR SDRAM Interface Registers
Function #3: Intel Reserved Registers
Device #2: Integrated Graphics Controller. Logically this appears as a PCI device residing on PCI bus
#0. Physically Device #2 contains the configuration registers fo r 3D, 2D, and display functions.
Table 12 shows the Device # assignment for the various internal GMCH devices.
Table 12. Device Number Assignment
GMCH Function Bus #0, Device#
Host-Hl, DDR SDRAM I/f, Legacy control. Device #0
Integrated Graphics Controller Device #2
Register Description
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852GM/852GMV Chipset GMCH Data sheet
3.2. Nomenclature for Access Attributes
Table 13 provides the nomenclature for the access attributes.
Table 13. Nomenclature for Access Attributes
RO Read Only. If a register is read only, writes to this register have no effect.
R/W Read/Write. A register with this attribute can be read and written.
R/W/L Read/Write/Lock. A register with this attribute can be read, written, and Lock.
R/WC Read/Write Clear. A register bit with this attribute can be read and written. However, a
write of a 1 clears (sets to 0) the corresponding bit and a write of a 0 has no effect.
R/WO Read/Write Onc e. A register bit with this attribute can be written to only once after power
up. After the first write, the bit becomes read only.
L Lock. A register bit with this attribute becomes Read Only after a lock bit is set.
Reserved Bits Some of the GMCH registers described in this section contain reserved bits. These bits are
labeled "Reserved”. Software must deal correctly with fields that are reserved. On reads,
software must use appropriate masks to extract the defined bits and not rely on reserved
bits being any particular value. On writes, software must ensure that the values of reserved
bit positions are preserved. That is, the values of reserved bit positions must first be read,
merged with the new values for other bit positions and then written back. Note the software
does not need to perform read, merge, and write operation for the Configuration Address
register.
Reserved Registers In addition to reserved bits within a register, the GMCH contains address locations in the
configuration space of the Host-Hub Interface Bridge entity that are marked either
"Reserved" or “Intel Reserved”. The GMCH responds to accesses to “Reserved” address
locations by completing the host cycle. When a “Reserved” register location is read, a zero
value is returned. (“Reserved” registers can be 8-bit, 16-bit, or 32-bit in size). Writes to
“Reserved” registers have no effect on the GMCH. Registers that are marked as “Intel
Reserved” must not be modified by system software. Writes to “Intel Reserved” registers
may cause system failure. Reads to “Intel Reserved” registers may return a non-zero
value.
Default Value upon a
Reset
Upon Reset, the GMCH sets all of its internal configuration registers to predetermined
default states. Some register values at reset are determined by external strapping options.
The default state represents the minimum functionality feature set required to successfully
bringing up the system. Hence, it does not represent the optimal system configuration. It is
the responsibility of the system initialization software (usually BIOS) to properly determine
the DRAM configurations, operating parameters and optional system features that are
applicable, and to program the GMCH registers accordingly.
S SW Semaphore.
A physical PCI bus #0 does not exist. The Hub Interface and the internal devices in the GMCH and
ICH4-M logically constitute PCI Bus #0 to configuration software.
Register Description
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852GM/852GMV Chipset GMCH Datasheet 47
3.3. Standard PCI Bus Configuration Mechanism
The PCI Bus defines a slot based “configuration space” that allows each device to contain up to eight
functions with each function containing up to 256, 8-bit configuration registers. The PCI specification
defines two bus cycles to access the PCI configuration space: Configuration Read and Configuration
Write. Memory and I/O spaces are supported directly by the CPU. Configuration space is supported by
a mapping mechanism implemented within the GMCH. The PCI 2.2 specification defines two
mechanisms to access configuration space, Mechanism #1 and Mechanism #2. The GMCH supports
only Mechanism #1.
The configuration access mechanism makes use of the CONFIG_ADDRESS Register (at I/O address
0CF8h though 0CFBh) and CO NFIG_DATA Register (at I/O address 0CFCh though 0CFFh). To
reference a configuration register a Dword I/O write cycle is used to place a value into
CONFIG_ADDRESS that specifies the PCI bus, the device on that bus, the function within the device,
and a specific configuration register of the device function being accessed. CONFIG_ADDRESS[31]
must be 1 to enable a configuration cycle. CONFIG_DATA then becomes a w indow into the four bytes
of configuration space specified by the contents of CONFIG_ADDRESS. Any read or write to
CONFIG_DATA will result in the GMCH translating th e CONFIG_ADDRESS into the appropriate
configuration cycle.
The GMCH is responsible for translating and routing the CPU’s I/O accesses to the
CONFIG_ADDRESS and CONFIG_DATA registers to internal GMCH configuration registers and Hub
Interface.
3.4. Routing Configuration Accesses
The GMCH supports one bus interface: the Hub Interface. PCI configuration cycles are selectively
routed to this interface. The GMCH is responsible for routing PCI configuration cycles to the proper
interface. PCI configuration cycles to the ICH4-M internal devices, and Primary PCI (including
downstream devices) are routed to the ICH4-M via the Hub Interface. A detailed descrip tion of the
mechanism for translating CPU I/O bus cycles to configuration cycles on one of the buses is described in
the following section.
3.4.1. PCI Bus #0 Configuration Mechanism
The GMCH decodes the Bus Number (bits 23:16) and the Device Number fields of the
CONFIG_ADDRESS register. If the Bus Number field of CONFIG_ADDRESS is 0 the configuration
cycle is targeting a PCI Bus #0 device.
The Host-Hub Interface Bridge entity within the GMCH is hardwired as Device #0 on PCI Bus #0.
Configuration cycles to any of the GMCH’s internal devices are confined to the GMCH and not sent
over Hub Interface. Accesses to disabled GMCH internal devices will be forwarded over the Hub
Interface as Type 0 Configuration Cycles.
3.4.2. Primary PCI and Downstream Configuration Mechanism
The ICH4-M compares the non-zero Bus Number with the SECONDARY BUS NUMBER and
SUBORDINATE BUS NUMBER registers of its P2P bridges to determine if the configuration cycle is
meant for Primary PCI or a downstream PCI bus.
Register Description
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852GM/852GMV Chipset GMCH Data sheet
3.5. Register Definitions
The GMCH contains four sets of software accessible registers accessed via the Host CPU I/O address
space, and they are as follows:
Control registers: I/O mapped into the CPU I/O space, which control access to PCI
configuration space via Configuration Mechanism #1 in the PCI 2.2 specification.
Internal configuration registers: residing within the GMCH, they are partitioned into two
logical device register sets (“logical” since they reside within the single physical device). The first
register set is dedicated to Host-HI Bridge functionality (i.e. DDR SDRAM configuration, other
chip-set operating parameters and optional features). The second regist er bl ock is for the
integrated gra p hi cs fu nct i on s.
Internal Memory Mapped configuration registers: resid i ng i n GMCH Devi ce # 0.
Internal Memory Mapped configuratio n registers and Legacy VGA registers: residing in the
GMCH Device #2 that controls the Integrated Graphics Controller.
The GMCH internal registers (I/O Mapped and Configuration registers) are accessible by the Host CPU.
The registers can be accessed as Byte, Word (16-bit), or Dword (32-bit) quantities, with the exception of
CONFIG_ADDRESS, which can only be accessed as a Dword. All multi-byte numeric fields use “little-
endian” ordering (i.e., lower addresses contain the least significant parts of the field).
Reserved Bits
Some of the GMCH registers described in this section contain reserved bits. These bits are labeled
“Reserved”. Software must deal correctly with fields that are reserved. On reads, software must use
appropriate masks to extract the defined bits and not rely on reserved bits being any particular value. On
writes, software must ensure that the values of reserved bit positions are preserved. That is, the values of
reserved bit positions must first be read, merged with the new valu es for other bit positions and then
written back.
Note: The software does not need to perform read, merge, and write operation for the configuration address
register.
Default Value upon Reset
Upon a full Reset, the GMCH sets all of its internal configuration registers to predetermined default
states. Some register values at reset are determined by external strapping op tions. The default state
represents the minimum functionality feature set required to successfully bring up the system. Hence, it
does not represent the optimal system configuration. It is the responsibility of the system initialization
software (usually BIOS) to properly determine the DDR SDRAM conf igur ations, operating parameters,
and optional system features that are applicable, and to program the GMCH registers accordingly.
Register Description
R
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852GM/852GMV Chipset GMCH Datasheet 49
3.6. I/O Mapped Registers
The GMCH contains two registers that reside in the CPU I/O address space: the Configuration Address
(CONFIG_ADDRESS) Register and the Conf iguration Data (CONFIG_DATA) Register. The
Configuration Address Register enables/disables the configuration space an d determines what portion of
configuration space is visible through the Configuration Data window.
3.6.1. CONFIG_ADDRESS – Configuration Address Register
I/O Address: 0CF8h Accessed as a Dword
Default Value: 00000000h
Access: Read/Write
Size: 32 bits
CONFIG_ADDRESS is a 32-bit register that can be accessed only as a Dword. A Byte or Word
reference will “pass through” the Configuration Address Register and the Hub Interface, onto the PCI
bus as an I/O cycle. The CONFIG_ADDRESS register contains the Bus Number, Device Numb er,
Function Number, and Register Number for which a subsequent configuration access is intended.
Figure 1. Configuration Address Re gister
R
1 0 27811151623 24 30 31 10
R 0 0 0 0
0
Reserved
Register Number
Function Number
Device Number
Bus Num ber
Reserved
Enable
Bit
Default
Register Description
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852GM/852GMV Chipset GMCH Data sheet
Bit Descriptions
31 Configuration Enable (CFGE): When this bit is set to 1, accesses to PCI configuration space are
enabled. If this bit is reset to 0, accesses to PCI configuration space are disabled.
30:24 Reserved
23:16 Bus Number: When the Bus Number is programmed to 00h the target of the Configuration Cycle is a
Hub Interface agent (GMCH, ICH4-M, etc.).
The Configuration Cycle is forwarded to Hub Interface if the Bus Number is programmed to 00h and the
GMCH is not the target (the device number is >= 2).
15:11 Device Number: This field selects one agent on the PCI bus selected by the Bus Number. When the Bus
Number field is “00” the GMCH decodes the Device Number field. The GMCH is always Device Number 0
for the Host-Hub Interface bridge entity. Therefore, when the Bus Number =0 and the Device Number=0-1
the internal GMCH devices are selected.
For Bus Numbers resulting in Hub Interface configuration cycles, the GMCH propagates the device
number field as A[15:11].
10:8 Function Number: This field is mapped to A[10:8] during Hub Interface configuration cycles. This allows
the configuration registers of a particular function in a multi-function device to be accessed. The GMCH
ignores configuration cycles to its internal Devices if the function number is not equal to 0.
7:2 Register Number: This field selects one register within a particular Bus, Device, and Function as
specified by the other fields in the Configuration Address Register. This field is mapped to A[7:2] during
Hub Interface Configuration cycles.
1:0 Reserved
Register Description
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852GM/852GMV Chipset GMCH Datasheet 51
3.6.2. CONFIG_DATA – Configuration Data Register
I/O Address: 0CFCh
Default Value: 00000000h
Access: Read/Write
Size: 32 bits
CONFIG_DATA is a 32-bit read/write window into configuration space. The portion of configuration
space that is referenced by CONFIG_DATA is determined by the contents of CONFIG_ADDRESS.
Figure 2. Configuration Data Registe r
31 0
Bit
Default
0
Configuration Data Window
Bit Descriptions
31:0 Configuration Data Window (CDW). If bit 31 of CONFIG_ADDRESS is 1 any I/O access that to the
CONFIG_DATA register will be mapped to configuration space using the contents of
CONFIG_ADDRESS.
Register Description
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852GM/852GMV Chipset GMCH Data sheet
3.7. VGA I/O Mapped Registers
If Device 2 is enabled, and Fun c tion 0 within device 2 is enabled for VGA, and IO_EN is set within
Function 0 then GMCH claims a set of I/O registers for legacy VGA function. Table 14 lists direct CPU
access registers and Table 15 lists registers that are index – data registers that are used to access internal
VGA register.
Table 14. VGA I/O Mapped Register List
Name Function Read @ Write @
ST00 VGA Input Status Register 0 3C2h
ST01 VGA Input Status Register 1 3BAh/3Dah
FCR VGA Feature Control Register 3CAh 3BAh/3DAh
MSR VGA Miscellaneous Output Register 3CCh 3C2h
Table 15. Index – Data Registers
Name Function Index IO Data IO
SRX Sequencer Registers 3C4 3C5
GRX Graphics Controller Registers 3CE 3CF
ARX Attribute Control Registers 3C0 3C0: Write
3C1: Read
DACMASK Pixel Data Mask Register -- 3C6h
DACSTATE DAC State Register -- 3C7 Read Only
DACRX Palette Read Index Register 3C7 Write Only --
DACWX Palette Write Index Register 3C8 Write Only
DACDATA Palette Data Register 3C9
CRX CRT Registers 3B4/3D4
(MDA/CGA)
3B5/3D5
(MDA/CGA)
Register Description
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852GM/852GMV Chipset GMCH Datasheet 53
3.8. Intel 852GM/852GMV GMCH Host-Hub Interface Bridge
Device Registers (Device #0, Function #0)
Table 16 summarizes the configuration space for Device #0, Function#0.
Table 16. GMCH Configuration Spac e - Device #0, Function#0
Register Name Register
Symbol Register
Start Register
End Default Value Access
Vendor Identification VID 00 01 8086h RO
Device Identification DID 02 03 3580h RO
PCI Command Register PCICMD 04 05 0006h RO,R/W
PCI Status Register PCISTS 06 07 0090h RO,R/WC
Revision Identification RID 08 08 01h RO
Sub-Class Code SUBC 0A 0A 00h RO
Base Class Code BCC 0B 0B 06h RO
Header Type HDR 0E 0E 80h RO
Subsystem Vendor
Identification
SVID 2C 2D 0000h R/WO
Subsystem Identification SID 2E 2F 0000h R/WO
Capabilities Pointer CAPPTR 34 34 40h RO
Capability Identification
(Product Specific)
CAPID 40 44 00000000A0h RO
Registers-RCOMP Base
Address
RRBAR 48 4B 00000000h R/W, RO
GMCH Misc. Control GMC 50 51 0000h R/W, RO
GMCH Graphics Control GGC 52 53 0030h R/W, RO
Device and Function Control
Register
DAFC 54 55 0000h R/W
Fixed Dram Hole Control FDHC 58 58 00h R/W, RO
Programmable Attribute MAP PAM (6:0) 59 5F 00h Each R/W, RO
System Management RAM
Control
SMRAM 60 60 02h R/W-L, RO
Extended System
Management RAM Control
ESMRAMC 61 61 38h RO-R/W-
RWC-L
Error Status Register ERRSTS 62 63 0000h R/WC
Error Command Register ERRCMD 64 65 0000h RO, R/W
SMI Command Register SMICMD 66 66 00h RO, R/W
SCI Command Register SCICMD 67 67 00h RO, R/W
Write Cache Control WCC 80 83 A4000002h
RO, R/W
Register Description
R
54 Intel
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852GM/852GMV Chipset GMCH Data sheet
Register Name Register
Symbol Register
Start Register
End Default Value Access
Capability Disable CAPD F4 F7 00000000h R/W
3.8.1. VID – Vendor Identification
Address Offset: 00h
Default Value: 8086h
Access: Read Only
Size: 16 bits
The VID Register contains the vendor identification number. This 16-bit register, combined with the
Device Identification Register, uniquely identifies any PCI device. Writes to this register have no effect.
Bit Descriptions
15:0 Vendor Identification (VID): This register field contains the PCI standard identification for Intel, 8086h.
3.8.2. DID – Device Identification
Address Offset: 02h
Default Value: 3580h
Access: Read Only
Size: 16 bits
This 16-bit register combined with the Vendor Identification register uniquely identifies any PCI device.
Writes to this register have no effect.
Bit Descriptions
15:0 Device Identification Number (DID): This is a 16-bit value assigned to the GMCH Host-Hub Interface
bridge, Device #0.
Register Description
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852GM/852GMV Chipset GMCH Datasheet 55
3.8.3. PCICMD – PCI Command Register
Address Offset: 04h
Default Value: 0006h
Access: Read Only, Read/Write
Size: 16 bits
Since GMCH Device #0 does not physically reside on PCI_A many of the bits are not implemented.
Bit Descriptions
15:10 Reserved
9 Fast Back-to-Back Enable (FB2B): This bit controls whether or not the master can do fast back-to-back
write. Since Device #0 is strictly a target this bit is not implemented and is hardwired to 0. Writes to this
bit position have no affect.
Default Value=0.
8
SERR Enable (SERRE): This bit is a global enable bit for Device #0 SERR messaging. The GMCH does
not have an SERR# signal, but communicates the SERR# condition by sending an SERR message to the
ICH4-M.
1 = Enable. GMCH is enabled to generate SERR messages over Hub Interface for specific Device 0
error conditions that are individually enabled in the ERRCMD register. The error status is reported in the
ERRSTS and PCISTS registers.
0 = SERR message is not generated by the GMCH for Device #0.
NOTE: This bit only controls SERR messaging for the Device #0. Device #1 has its own SERRE bit to
control error reporting for error conditions occurring on Device #1. The two control bits are used in a
logical OR manner to enable the SERR Hub Interface message mechanism.
Default Value=0.
7 Address/Data Stepping Enable (ADSTEP): Address/data stepping is not implemented in the GMCH,
and this bit is hardwired to 0. Writes to this bit position have no effect.
Default Value=0.
6 Parity Error Enable (PERRE): PERR# is not implemented by GMCH and this bit is hardwired to 0.
Writes to this bit position have no effect.
Default Value=0.
5 VGA Palette Snoop Enable (VGASNOOP): The GMCH does not implement this bit and it is hardwired
to a 0. Writes to this bit position have no effect.
Default Value=0.
4 Memory Write and Invalidate Enable (MWIE): The GMCH will never issue memory write and invalidate
commands. This bit is therefore hardwired to 0. Writes to this bit position will have no effect.
Default Value=0.
3 Special Cycle Enable (SCE): The GMCH does not implement this bit and it is hardwired to a 0. Writes to
this bit position have no effect.
Default Value=0.
2 Bus Master Enable (BME): The GMCH is always enabled as a master on HI. This bit is hardwired to a
“1”. Writes to this bit position have no effect.
Default Value=1.
1 Memor y Access Enable (M AE): The GMCH always allows access to main System Memory. This bit is
not implemented and is hardwired to 1. Writes to this bit position have no effect.
Default Value=1.
Register Description
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56 Intel
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852GM/852GMV Chipset GMCH Data sheet
Bit Descriptions
0 I/O Access Enable (IOAE): This bit is not implemented in the GMCH and is hardwired to a 0. Writes to
this bit position have no effect.
3.8.4. PCI Status Register
Address Offset: 06h
Default Value: 0090h
Access: Read Only, Read/Write/Clear
Size: 16 bits
PCISTS is a 16-bit status register that reports the occurrence of error events on Device #0’s PCI
interface. Bit 14 is read/write clear. All other bits are Read Only. Since GMCH Device #0 does not
physically reside on PCI_A many of the bits are not implemented.
Bit Descriptions
15 Detected Parity Error (DPE): The GMCH does not implement this bit and it is hardwired to a 0. Writes to this
bit position have no effect.
Default Value=0.
14 Signaled System Error (SSE): R/WC: This bit is set to 1 when GMCH Device #0 generates an SERR
message over HI for any enabled Device #0 error condition. Device #0 error conditions are enabled in the
PCICMD and ERRCMD registers. Device #0 error flags are read/reset from the PCISTS or ERRSTS
registers. Software sets SSE to 0 by writing a 1 to this bit.
Default Value=0.
13 Received Master Abort Status (RMAS): R/WC: This bit is set when the GMCH generates a HI request that
receives a Master Abort completion packet or Master Abort Special Cycle. Software clears this bit by writing a
1 to it.
Default Value=0.
12 Received Target Abort Status (RTAS): R/WC: This bit is set when the GMCH generates a HI request that
receives a Target Abort completion packet or Target Abort Special Cycle. Software clears this bit by writing a
1 to it. If bit 6 in the ERRCMD is set to a one and an Serr# special cycle is generated on the HL bus.
Default Value=0.
11 Signaled Target Abort Status (STAS): The GMCH will not generate a Target Abort HI completion packet or
Special Cycle. This bit is not implemented in the GMCH and is hardwired to a 0. Writes to this bit position
have no effect.
Default Value=0.
10:9 DEVSEL Timing (DEVT): These bits are hardwired to “00”. Writes to these bit positions have no affect.
Device #0 does not physically connect to PCI_A. These bits are set to “00” (fast decode) so that the GMCH
does not limit optimum DEVSEL timing for PCI_A.
Default Value=0.
8 Master Data Parity Error Detected (DPD): PERR signaling and messaging are not implemented by the
GMCH therefore this bit is hardwired to 0. Writes to this bit position have no effect.
Default Value=0.
7 Fast Back-to-Back (FB2B): This bit is hardwired to 1. Writes to these bit positions have no effect. Device #0
does not physically connect to PCI_A. This bit is set to 1 (indicating fast back-to-back capability) so that the
GMCH does not limit the optimum setting for PCI_A.
Default Value=1.
6:5 Reserved
Register Description
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852GM/852GMV Chipset GMCH Datasheet 57
Bit Descriptions
4 Capability List (CLIST): This bit is hardwired to 1 to indicate to the configuration software that this
device/function implements a list of new capabilities. A list of new capabilities is accessed via register
CAPPTR at configuration address offset 34h.
Default Value=1.
3:0 Reserved
3.8.5. RID – Register Identification
Address Offset: 08h
Default Value: 01h
Access: Read Only
Size: 8 bits
This register contains the revision number of the GMCH Device #0. These bits are read only and writes
to this register have no effect.
Bit Descriptions
7:0 Revision Identification Number (RID): This is an 8-bit value that indicates the revision identification
number for the GMCH Device #0.
Default Value=01h
3.8.6. SUBC – Sub Class Code
Address Offset: 0Ah
Default Value: 00h
Access: Read Only
Size: 8 bits
This register contains the Sub-Class Code for the GMCH Device #0. This code is 00h indicating a Host
Bridge device.
Bit Descriptions
7:0 Sub-Class Code (SUBC): This is an 8-bit value that indicates the category of Bridge into which the GMCH
falls. The code is 00h indicating a Host Bridge.
Default Value=0
Register Description
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58 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.8.7. BCC – Base Class Code
Address Offset: 0Bh
Default Value: 06h
Access: Read Only
Size: 8 bits
This register contains the Base Class Code of the Intel 852GM/852GMV GMCH Device #0. This cod e is
06h indicating a Bridge device.
Bit Descriptions
7:0 Base Class Code (BASEC): This is an 8-bit value that indicates the Base Class Code for the Intel
852GM/852GMV GMCH. This code has the value 06h, indicating a Bridge device.
3.8.8. HDR – Header Type
Address Offset: 0Eh
Default Value: 80h
Access: Read Only
Size: 8 bits
This register identifies the header layout of the configuration space. No physical register exists at this
location.
Bit Descriptions
7:0 PCI Header (HDR): This field always returns 80 to indicate that Device 0 is a multifunction device. If
Functions other than 0 are disabled this field returns a 00 to indicate that the Intel 852GM/852GMV GMCH is
a single function device with standard header layout. The default is 80; Writes to this location have no effect.
3.8.9. SVID – Subsystem Vendor Identification
Address Offset: 2Ch
Default Value: 0000h
Access: Read/Write Once
Size: 16 bits
This value is used to identify the vendor of the subsystem.
Bit Descriptions
15:0 Subsystem Vendor ID (SUBVID): This field should be programmed during boot-up to indicate the vendor of
the system board. After it has been written once, it becomes read only.
Default Value=0
Register Description
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852GM/852GMV Chipset GMCH Datasheet 59
3.8.10. SID – Subsystem Identification
Address Offset: 2Eh
Default Value: 0000h
Access: Read/Write Once
Size: 16 bits
This value is used to identify a particular subsystem.
Bit Descriptions
15:0 Subsystem ID (SUBID): This field should be programmed during BIOS initialization. After it has been
written once, it becomes read only.
Default Value=0
3.8.11. CAPPTR – Capabilities Pointer
Address Offset: 34h
Default Value: 40h
Access: Read Only
Size: 8 bits
The CAPPTR provides the offset that is the pointer to the location of the first device capability in the
capability list.
Bit Descriptions
7:0 Pointer to the offset of the first capability ID register block: In this case the first capability is the
Product-Specific Capability, which is located at offset 40h.
Register Description
R
60 Intel
®
852GM/852GMV Chipset GMCH Data sheet
3.8.12. CAPID Capability Identification Register (Device 0)
Address Offset: 40h – 44h
Default: 0F_F105_F009h
Access: Read Only
Size 40 bits
The Capability Iden tification Register uniquely identifies chipset capabilities as defined in the table
below. The bits in this register are intended to define a capability ceiling for each feature, not a
capability select. The capability selection for each feature is implemented elsewhere. The mechanism to
select the capability for each feature must comprehend th ese capabilities registers and not allow a
selected setting above the ceiling specified in these registers. The BIOS must read this register to
identify the SKU of the pa rt and comprehend the capabilities specified within when configuring the
effected portions of the GMCH.
The default setting, in most cases, allows the maximum capability. Exceptions are no ted in the
individual bits. This register is Read Only. Writes to this register have no effect.
Bit Descriptions
39:37 Capability ID [2:0 ]:
000-100 =reserved
101= Intel 852GM/852GMV GMCH
110-111 = reserved
36:30 Reserved
29 0 = Reserved
1 = Device #1 and associated System Memory and IO spaces are disabled. In addition, Next_Pointer =
00h, APBASE is read only, and Aperture Global Access is Disabled.
28 Reserved
27:24 CAPREG Version: This field has the value 0001b to identify the first revision of the CAPREG definition.
23:16 Cap_length: This field has the value 05h indicating the structure length.
15:8 Reserved
7:5 CAP_ID:
000 = Reserved
100 = Reserved
101 = Intel 852GM/852GMV GMCH
4:0 Reserved
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 61
3.8.13. RRBAR – Register Range Base Address Register (Device 0)
Address Offset: 48 4Bh
Default Value: 00000000h
Access: Read/Write, Read Only
Size: 32 bits
This register requests a 64-kB allocation for the Device registers. The base address is defined by bits 31
to 16 and can be used to access device configuration registers. Only Dword aligned writes are allowed to
this space. See the table below for address map within the 64-kB space. This addressing mechanism may
be used to write to registers that modify the device address map (includes all the BARs, PAMs, SMM
registers, Pre-Allocated System Memory registers etc). However, before using or allowing the use of the
modified address map the bios must synchronize using an IO or Read cycle.
Note: The GTLB cannot be enabled/disabled using this mechanism.
Bit Description
31:16 Memory Base Address—R/W: Set by the OS, these bits correspond to address signals [31:16].
15:0 Reserved
Address Range
Sub Ranges
Description
0000h to 00FFh Read/Write (As in Configuration Space): Maps to 00–FFh
of Device 0, Function 0 register space.
0100h to 01FFh Read/Write (As in Configuration Space): Maps to 00–FFh
of Device 0, Function 1 register space.
0200h to 02FFh Reserved
0300h to 03FFh Read/Write (As in Configuration Space): Maps to 00–FFh
of Device 0, Function 3 register space.
0400h to 07FFh Reserved
0800h to 08FFh Read/Write (As in Configuration Space): Maps to 00–FFh
of Device 1, Function 0 register space.
0900h to 0FFFh Reserved
1000h to 10FFh Read/Write (As in Configuration Space): Maps to 00–FFh
of Device 2, Function 0 register space.
1100h to 11FFh Read/Write (As in Configuration Space): Maps to 00–FFh
of Device 2, Function 1 register space.
1200h to 7FFFh Reserved
8000h to 8FFFh System Memory RCOMP memory Range.
0000h to FFFFh
Space
9000h to FFFFh Reserved
Register Description
R
62 Intel
®
852GM/852GMV Chipset GMCH Data sheet
3.8.14. GMC – GMCH Miscellaneous Control Register (Device 0)
Address Offset: 50–51h
Default Value: 0000h
Access: Read/Write, Read Only
Size: 16 bits
Bit Descriptions
15:10 Reserved
9 Reserved
8 RRBAR Access Enable—R/W:
1 = Enables the RRBAR space.
0 = Disable
7:1 Reserved
0 MDA Present (MDAP)—R/W:
This bit should not be set when the VGA Enable bit is not set. If the VGA enable bit is set, then
accesses to IO address range x3BCh–x3BFh are forwarded to Hub Interface. If the VGA enable bit is
not set then accesses to IO address range x3BCh–x3BFh are treated just like any other IO accesses.
MDA resources are defined as the following:
Memory: 0B0000h – 0B7FFFh
I/O: 3B4h, 3B5h, 3B8h, 3B9h, 3BAh, 3BFh,
(including ISA address aliases, A[15:10] are not used in decode)
Any I/O reference that includes the I/O locations listed above, or their aliases, will be forwarded to Hub
Interface even if the reference includes I/O locations not listed above.
The following table shows the behavior for all combinations of MDA and VGA:
VGA MDA Behavior
0 0 All References to MDA and VGA go to Hub Interface (Default)
0 1 Reserved
1 0 All References to VGA go to PCI.
MDA-only references (I/O address 3BF and aliases)
will go to Hub Interface.
1 1 VGA References go to PCI; MDA References
go to Hub Interface
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 63
3.8.15. GGC – GMCH Graphics Control Register (Device 0)
Address Offset: 52–53h
Default Value: 0030h
Access: Read/Write, Read Only
Size: 16 bits
Bit Descriptions
15:7 Reserved
6:4 Graphics Mode Select (GMS): This field is used to select the amount of Main System Memory that is pre-
allocated to support the Internal Graphics Device in VGA (non-linear) and Native (linear) modes. The BIOS
ensures that System Memory is pre-allocated only when Internal Graphics is enabled.
000 = No System Memory pre-allocated. Device #2 (IGD) does not claim VGA cycles (Mem and IO), and the
Sub-Class Code field within Device #2 Function #0 Class Code register is 80.
001 = DVMT (UMA) mode, 1 MB of System Memory pre-allocated for frame buffer.
010 = DVMT (UMA) mode, 4 MB of System Memory pre-allocated for frame buffer.
011 = DVMT (UMA) mode, 8 MB of System Memory pre-allocated for frame buffer.
100 = DVMT (UMA) mode, 16 MB of System Memory pre-allocated for frame buffer.
101 = DVMT (UMA) mode, 32 MB of System Memory pre-allocated for frame buffer.
All other combinations reserved.
3:2 Reserved
1 IGD VGA Disable (IVD):
1 = Disable. Device #2 (IGD) does not claim VGA cycles (Mem and IO), and the Sub-Class Code field within
Device #2 Function #0 Class Code register is 80.
0 = Enable (Default). Device #2 (IGD) claims VGA memory and IO cycles, the Sub-Class Code within Device
#2 Class Code register is 00.
0 Reserved
Register Description
R
64 Intel
®
852GM/852GMV Chipset GMCH Data sheet
3.8.16. DAFC – Device and Function Control Register (Device 0)
Address Offset: 54–55h
Default Value: 0000h
Access: Read/Write
Size: 16 bits
This 16-bit register controls the visibility of devices and functions within the GMCH to configurations
software.
Bit Description
15:8 Reserved
7 Device #2 Disable:
1 = Disabled.
0 = Enabled.
6:3 Reserved
2 Device #0 Function #3 Disable.
1 = Disable Function #3 registers within Device #0 and all associated DDR SDRAM and I/O ranges.
0 = Default is #0, Function #1 within Device #0 is enabled.
1 Reserved
0 Device #0 Function #1 Disable:
1 = Disable Function #1 within Device #0.
0 = Default is 0, Function #1 within Device #0 is enabled.
3.8.17. FDHC – Fixed DRAM Hole Control Register (Device 0)
Address Offset: 58h
Default Value: 00h
Access: Read/Write
Size: 8 bits
This 8-bit register controls a single fixed DDR SDRAM hole: 15–16 MB.
Bit Description
7 Hole Enable (HEN): This field enables a memory hole in DDR SDRAM space. Host cycles matching
an enabled hole are passed on to ICH4-M through Hub Interface. The Intel 852GM/852GMV GMCH
will ignore Hub Interface cycles matching an enabled hole.
NOTE: A selected hole is not re-mapped.
0 = None
1 = 15 MB–16 MB (1MBs)
6:0 Reserved
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 65
3.8.18. PAM(6:0) – Programmable Attribute Map Register (Device 0)
Address Offset: 59–5Fh
Default Value: 00h Each
Attribute: Read/Write
Size: 4 bits/register, 14 registers
The Intel 852GM/852GMV GMCH allows programmable DDR SDRAM attributes on 13 Legacy
System Memory segments of various sizes in the 640 kB –1 MB address range. Seven Programmable
Attribute Map (PAM) Registers are used to support these features. Cacheability of these areas is
controlled via the MTRR registers in the P6 processor. Two bits are used to specify System Memory
attributes for each System Memory segment. These bits apply to both host and Hub Interface initiator
accesses to the PAM areas. These attributes are:
RE - Read Enable. When RE = 1, the CPU read accesses to the corresponding System Memory
segment are claimed by the Intel 852GM/852GMV GMCH and directed to main System Memory.
Conversely, when RE = 0, the host read accesses are directed to PCI0.
WE - Write Enable. When WE = 1, the host write accesses to the corresponding System Memory
segment are claimed by the Intel 852GM/852GMV GMCH and directed to main System Memory.
Conversely, when WE = 0, the host write accesses are directed to PCI0.
The RE and WE attributes permit a System Memory segment to be Read Only, Write Only, Read/Write,
or disabled. For example, if a System Memory segment has RE = 1 and WE = 0, the segment is Read
Only.
Each PAM Register controls two regions, typically 16 kB in size. Each of these regions has a 4-bit field.
The four bits that control each region have the same encoding and are defined in the following table.
Register Description
R
66 Intel
®
852GM/852GMV Chipset GMCH Data sheet
Table 17. Attribute Bit Assignment
Bits [7, 3]
Reserved Bits [6, 2]
Reserved Bits [5, 1]
WE Bits [4, 0]
RE Description
X X 0 0 Disabled. DDR SDRAM is disabled and all
accesses are directed to Hub Interface. The Intel
852GM/852GMV GMCH does not respond as a
Hub Interface target for any read or write access
to this area.
X X 0 1 Read Only. Reads are forwarded to DDR
SDRAM and writes are forwarded to Hub
Interface for termination. This write protects the
corresponding DDR SDRAM segment. The Intel
852GM/852GMV GMCH will respond as a Hub
Interface target for read accesses but not for any
write accesses.
X X 1 0 Write Only. Writes are forwarded to DDR
SDRAM and reads are forwarded to the Hub
Interface for termination. The Intel
852GM/852GMV GMCH will respond as a Hub
Interface target for write accesses but not for any
read accesses.
X X 1 1 Read/Write. This is the normal operating mode of
main System Memory. Both read and write cycles
from the host are claimed by the Intel
852GM/852GMV GMCH and forwarded to DDR
SDRAM. The Intel 852GM/852GMV GMCH will
respond as a Hub Interface target for both read
and write accesses.
As an example, consider a BIOS that is implemented on the expansion bus. During th e initialization
process, the BIOS can be shadowed in main System Memory to increase the system performance. When
BIOS is shadowed in main System Memory, it shou ld be copied to the same ad dress locatio n. To
shadow the BIOS, the attributes for that address range should be set to write only. The BIOS is
shadowed by first doing a read of that address. This read is forw arded to the expansion bu s. The host
then does a write of the same address, which is directed to main System Memory. After the BIOS is
shadowed, the attributes for th at System Memory area are set to read only so that all writes are
forwarded to the expansion bus. Figure 3 and Table 18 show the PAM registers and the associated
attribute bits.
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 67
Figure 3. PAM Registers
pam
REWERE R RWERR
76 5 4 3 21 0
PAM6
PAM5
PAM4
PAM3
PAM2
PAM1
PAM0
Read Enable (R/W)
1=Enable
0=Disable
Write Enable (R/W)
1=Enable
0=Disable
Reserved
Reserved
Read Enable (R/W)
1=Enable
0=Disable
Write Enable (R/W)
1=Enable
0=Disable
Reserved
Reserved
5Fh
5Eh
5Dh
5Ch
5Bh
5Ah
59h
Offset
Table 18. PAM Registers and Associated System Memory Segments
PAM Reg Attribute Bits System Memory Segment Offset
PAM0[3:0] Reserved
Comments
59h
PAM0[7:4] R R WE RE 0F0000h–0FFFFFh BIOS Area 59h
PAM1[3:0] R R WE RE 0C0000h–0C3FFFh ISA Add-on BIOS 5Ah
PAM1[7:4] R R WE RE 0C4000h–0C7FFFh ISA Add-on BIOS 5Ah
PAM2[3:0] R R WE RE 0C8000h–0CBFFFh ISA Add-on BIOS 5Bh
PAM2[7:4] R R WE RE 0CC000h–0CFFFFh ISA Add-on BIOS 5Bh
PAM3[3:0] R R WE RE 0D0000h–0D3FFFh ISA Add-on BIOS 5Ch
PAM3[7:4] R R WE RE 0D4000h–0D7FFFh ISA Add-on BIOS 5Ch
PAM4[3:0] R R WE RE 0D8000h–0DBFFFh ISA Add-on BIOS 5Dh
PAM4[7:4] R R WE RE 0DC000h–0DFFFFh ISA Add-on BIOS 5Dh
PAM5[3:0] R R WE RE 0E0000h–0E3FFFh BIOS Extension 5Eh
PAM5[7:4] R R WE RE 0E4000h–0E7FFFh BIOS Extension 5Eh
PAM6[3:0] R R WE RE 0E8000h–0EBFFFh BIOS Extension 5Fh
PAM6[7:4] R R WE RE 0EC000h–0EFFFFh BIOS Extension 5Fh
For details on overall system address mapping scheme see the Address Decoding section of this
document.
Register Description
R
68 Intel
®
852GM/852GMV Chipset GMCH Data sheet
DOS Application Area (00000h–9FFFh)
The DOS area is 640 kB in size and it is further divided into two parts. The 512-kB area at 0 to 7FFFFh
is always mapped to the main System Memory contro lled by the Intel 852GM/852GMV GMCH, while
the 128-kB address range from 080000 to 09FFFFh can be mapped to PCI0 or to main DDR SDRAM.
By default this range is mapped to main System Memory and can be declared as a main Syste m Memory
hole (accesses forwarded to PCI0) via Intel 852GM/852GMV GMCH’s FDHC configuration register.
Video Buffer Area (A0000h–BFFFFh)
Attribute bits do not contro l this 128-kB area. The host -initiated cycles in this region are always
forwarded to either PCI0 or PCI2 unless this range is accessed in SMM mode. Routing of accesses is
controlled by the Legacy VGA control mechanism of the “virtual” PCI-PCI bridge device embedded
within the Intel 852GM/852GMV GMCH.
This area can be programmed as SMM area via the SMRAM register. When used as an SMM space, this
range can not be accessed from Hub Interface.
Expansion Area (C0000h–DFFFFh)
This 128-kB area is divided into eight 16-kB segments that can be assigned with different attributes via
PAM control register as defined in table 17 and table 18.
Extended System BIOS Area (E0000h–EFFFFh)
This 64-kB area is divided into four 16-kB segments that can be assigned with different attributes via
PAM control register as defined in table 17 and table 18.
System BIOS Area (F0000h–FFFFFh)
This area is a single 64-kB segment that can be assigned with different attributes via PAM control
register as defined in table 17 and table 18.
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 69
3.8.19. SMRAM – System Management RAM Ctrl Register (Device 0)
Address Offset: 60h
Default Value: 02h
Access: Read/Write/Lock, Read Only
Size: 8 bits
The SMRAM register controls how accesses to Compatible and Extended SMRAM spaces are treated.
The Open, Close, and Lock bits function only when G_SMRAME bit is set to a 1. Also, the Op en bit
must be reset before the LOCK bit is set.
Bit Description
7 Reserved
6 SMM Space Open (D_OPEN): When D_OPEN=1 and D_LCK=0, the SMM space DDR SDRAM is made
visible even when SMM decode is not active. This is intended to help BIOS initialize SMM space. Software
should ensure that D_OPEN=1 and D_CLS=1 are not set at the same time. When D_LCK is set to a 1,
D_OPEN is reset to 0 and becomes read only.
5 SMM Space Closed (D_CLS): When D_CLS = 1 SMM space DDR SDRAM is not accessible to data
references, even if SMM decode is active. Code references may still access SMM space DDR SDRAM.
This will allow SMM software to reference “through” SMM space to update the display even when SMM is
mapped over the VGA range. Software should ensure that D_OPEN=1 and D_CLS=1 are not set at the
same time. D_CLS applies to all SMM spaces (Cseg, Hseg, and Tseg).
4 SMM Space Locked (D_LCK): When D_LCK is set to 1 then D_OPEN is reset to 0 and D_LCK, D_OPEN,
G_SMRAME, C_BASE_SEG, GMS, DRB, DRA, H_SMRAM_EN, TSEG_SZ and TSEG_EN become read
only. D_LCK can be set to 1 via a normal configuration space write but can only be cleared by a Full Reset.
The combination of D_LCK and D_OPEN provide convenience with security. The BIOS can use the
D_OPEN function to initialize SMM space and then use D_LCK to “lock down” SMM space in the future so
that no application software (or BIOS itself) can violate the integrity of SMM space, even if the program has
knowledge of the D_OPEN function.
3 Global SMRAM Enable (G_SMRAME): If set to a 1, then Compatible SMRAM functions is enabled,
providing 128 kB of DRAM accessible at the A0000h address while in SMM (ADS# with SMM decode). To
enable Extended SMRAM function this bit has be set to 1. Refer to the section on SMM for more details.
Once D_LCK is set, this bit becomes read only.
2:0 Compatible SMM Space Base Segment (C_BASE_SEG)—RO: This field indicates the location of SMM
space. “SMM DRAM” is not remapped. It is simply “made visible” if the conditions are right to access SMM
space, otherwise the access is forwarded to Hub Interface. C_BASE_SEG is hardwired to 010 to indicate
that the Intel 852GM/852GMV GMCH supports the SMM space at A0000h–BFFFFh.
Register Description
R
70 Intel
®
852GM/852GMV Chipset GMCH Data sheet
3.8.20. ESMRAMC – Extended System Management RAM Control
(Device 0)
Address Offset: 61h
Default Value: 38h
Access: Read/Write
Size: 8 bits
The Extended SMRAM register controls the configuration of Extended SMRAM space. The Extended
SMRAM (E_SMRAM) memory provides a write-back cacheable SMRAM me mory space that is above
1 MB.
Bit Description
7 H_SMRAM_EN (H_SMRAME): Controls the SMM memory space location (i.e., above 1 MB or below 1
MB). When G_SMRAME is 1 and H_SMRAME this bit is set to 1, the high SMRAM memory space is
enabled. SMRAM accesses from 0FEDA0000h to 0FEDBFFFFh are remapped to DDR SDRAM address
000A0000h to 000BFFFFh.
Once D_LCK is set, this bit becomes read only.
6 E_SMRAM_ERR (E_SMERR): This bit is set when CPU accesses the defined DDR SDRAM ranges in
Extended SMRAM (High System Memory and T-segment) while not in SMM space. It is software’s
responsibility to clear this bit. The software must write a 1 to this bit to clear it.
5 SMRAM_Cache (SM_CACHE): Intel 852GM/852GMV GMCH forces this bit to 1.
4 SMRAM_L1_EN (SM_L1): Intel 852GM/852GMV GMCH forces this bit to 1.
3 SMRAM_L2_EN (SM_L2): Intel 852GM/852GMV GMCH forces this bit to 1.
2:1 Reserved
0 TSEG_EN (T_EN): Enabling of SMRAM memory (TSEG, 1 Mbytes of additional SMRAM memory) for
Extended SMRAM space only. When G_SMRAME =1 and TSEG_EN = 1, the TSEG is enabled to appear
in the appropriate physical address space.
Once D_LCK is set, this bit becomes read only.
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 71
3.8.21. ERRSTS – Error Status Register (Device 0)
Address Offset: 62–63h
Default Value: 0000h
Access: Read/Write Clear
Size: 16 bits
This register is used to report various error conditions via Hub Interface special cycles. An SERR, SMI,
or SCI Error Hub Interface special cycle may be generated on a zero to one transition of any of these
flags when enabled in the PCICMD/ERRCMD, SMICMD, or SCICMD registers respectively.
Bit Description
15:14 Reserved
13 FSB Strobe Glitch Detected (FSBAGL): When this bit is set to 1 the Intel 852GM/852GMV GMCH has
detected a glitch on one of the FSB strobes. Writing a 1 to it clears this bit.
12 Intel 852GM/852GMV GMCH Software Generated Event for SMI:
1 = This indicates the source of the SMI was a Device #2 Software Event.
0 = Software must write a 1 to clear this bit.
11 Intel 852GM/852GMV GMCH Thermal Sensor Event for SMI/SCI/SERR:
1 = Indicates that a Intel 852GM/852GMV GMCH Thermal Sensor trip has occurred and an SMI, SCI or
SERR has been generated. Note that the status bit is set only if a message is sent based on Thermal
event enables in Error command, SMI command and SCI command registers. Note that a trip point
can generate one of SMI. SCI or SERR interrupts (two or more per event is illegal). Multiple trip
points can generate the same interrupt, if software chooses this mode subsequent trips may be lost.
0 = Software must write a 1 to clear this status bit. If this bit is set then an interrupt message will not be
sent on a new thermal sensor event.
10 Reserved
9 LOCK to non-DDR SDRAM Memory Flag (LCKF)—R/WC:
1 = Indicates that a CPU initiated LOCK cycle targeting non-DDR SDRAM memory space occurred.
0 = Software must write a 1 to clear this status bit
8 Received Refresh Timeout—R/WC:
1 = This bit is set when 1024 memory core refresh are Queued up.
0 = Software must write a 1 to clear this status bit.
7 DRAM Throttle Flag (DTF)—R/ W C:
1 = Indicates that the DDR SDRAM Throttling condition occurred.
0 = Software must write a 1 to clear this status bit.
6 Reserved
5 Received Unimplemented Special C ycle Hub Interface Completion Packet FLAG (UNSC)—R/WC:
1 = Indicates that the Intel 852GM/852GMV GMCH initiated a Hub Interface request that was terminated
with an Unimplemented Special Cycle completion packet.
0 = Software must write a 1 to clear this status bit.
4:0 Reserved
Register Description
R
72 Intel
®
852GM/852GMV Chipset GMCH Data sheet
3.8.22. ERRCMD – Error Command Register (Device 0)
Address Offset: 64–65h
Default Value: 0000h
Access: Read/Write
Size: 16 bits
This register enables various errors to generate a SERR Hub Interface special cycle. Since the Intel
852GM/852GMV GMCH does not have a SERR# signal, SERR messages are passed from the Intel
852GM/852GMV GMCH to the ICH4-M over Hub Interface. The actual generation of the SERR
message is globally enab l ed for Device #0 via the PCI C omm and register.
Note: An error can generate one and only one Hub Interface error special cycle. It is software’s responsibility
to make sure that when an SERR error message is enabled for an erro r condition, SMI and SCI error
messages are disabled for that same error condition.
Bit Description
15:14 Reserved
13 SERR on FSB Strobe Glitch : When this bit is asserted, the Intel 852GM/852GMV GMCH will generate a HI
SERR message when a glitch is detected on one of the FSB Strobes.
12 Reserved
11 SERR on Intel 852GM/852GMV GMCH Thermal Sensor Event:
1 = The Intel 852GM/852GMV GMCH generates a SERR Hub Interface special cycle on a thermal sensor
trip that requires an SERR. The SERR must not be enabled at the same time as the SMI/SCI for a
thermal sensor trip event.
0 = Software must write a 1 to clear this status bit.
10 Reserved
9 SERR on LOCK to n on-DDR SDRAM Memory:
1 = The Intel 852GM/852GMV GMCH generates an SERR Hub Interface special cycle when a CPU initiated
LOCK transaction targeting non-DDR SDRAM memory space occurs.
0 = Disable. Reporting of this condition is disabled.
8 SERR on DDR SDRAM Refresh timeout:
1 = The Intel 852GM/852GMV GMCH generates an SERR Hub Interface special cycle when a DDR SDRAM
Refresh timeout occurs.
0 = Disable. Reporting of this condition is disabled.
7 SERR on DDR SDRAM Throttle Condition:
1 = The Intel 852GM/852GMV GMCH generates an SERR Hub Interface special cycle when a DDR SDRAM
Read or Write Throttle condition occurs.
0 = Disable. Reporting of this condition is disabled.
6 SERR on Receiving Target Abort on Hub Interface:
1 = The Intel 852GM/852GMV GMCH generates an SERR Hub Interface special cycle when an Intel
852GM/852GMV GMCH originated Hub Interface cycle is terminated with a Target Abort.
0 = Disable. Reporting of this condition is disabled.
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 73
Bit Description
5 SERR on Receiving Unimplemented Special Cycle Hub Interface Completion Packet:
1 = The Intel 852GM/852GMV GMCH generates an SERR Hub Interface special cycle when an Intel
852GM/852GMV GMCH initiated Hub Interface request is terminated with a Unimplemented Special
Cycle completion packet.
0 = Disable. Reporting of this condition is disabled.
4:2 Reserved
1 SERR on Multiple-bit ECC Error:
1 = Reserved
0 = For systems that do not support ECC, this field must be set to 0 (Intel 852GM/852GMV GMCH only).
0 SERR on Single-bit ECC Error:
1 = Reserved
0 = For systems that do not support ECC, this field must be set to 0 (Intel 852GM/852GMV GMCH only).
Register Description
R
74 Intel
®
852GM/852GMV Chipset GMCH Data sheet
3.8.23. SMICMD – SMI Error Command Register (Device 0)
Address Offset: 66h
Default Value: 00h
Access: Read/Write
Size: 8 bits
This register enables various errors to generate an SMI Hub Interface special cycle. When an error flag is
set in the ERRSTS register it can generate a SERR, SMI, or SCI Hub Interface special cycle when
enabled in the ERRCMD, SMICMD, or SCICMD registers respectively.
Note: An error can generate one and only one Hub Interface error special cycle. It is software’s responsibility
to make sure that when an SMI e rror messa ge is enable d for an error condition, SERR and SCI error
messages are disabled for that same error condition.
Bit Description
7:4 Reserved
3 SMI on Intel 852GM/852GMV GMCH Thermal Sensor Trip:
1 = An SMI Hub Interface special cycle is generated by Intel 852GM/852GMV GMCH when the thermal sensor
trip requires an SMI. A thermal sensor trip point cannot generate more than one special cycle.
2 Reserved
1 SMI on Multiple-bit ECC Error:
1 = Reserved
0 = For systems that do not support ECC, this field must be set to 0(Intel 852GM/852GMV GMCH only).
0 SMI on Single-bit ECC Error:
1 = Reserved
0 = For systems that do not support ECC, this field must be set to 0 (Intel 852GM/852GMV GMCH only).
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 75
3.8.24. SCICMD – SCI Error Command Register (Device 0)
Address Offset: 67h
Default Value: 00h
Access: Read/Write
Size: 8 bits
This register enables various errors to generate a SCI Hub Interface special cycle. When an error flag is
set in the ERRSTS register it can generate a SERR, SMI, or SCI Hub Interface special cycle when
enabled in the ERRCMD, SMICMD, or SCICMD registers respectively.
Note: An error can generate one and only one Hub Interface error special cycle. It is software’s responsibility
to make sure that when an SCI error message is enabled for an error condition, SERR and SMI error
messages are disabled for that same error condition.
Bit Description
7:4 Reserved
3 SCI on Intel 852GM/852GMV GMCH Thermal Sensor Trip:
1 = An SCI Hub Interface special cycle is generated by Intel 852GM/852GMV GMCH when the thermal
sensor trip requires an SCI. A thermal sensor trip point cannot generate more than one special cycle.
2 Reserved
1 SCI on Multiple-bit ECC Error:
1 = Reserved
0 = For systems that do not support ECC, this field must be set to 0 (Intel 852GM/852GMV GMCH only).
0 SCI on Single-bit ECC Error:
1 = Reserved
0 = For systems that do not support ECC, this field must be set to 0 (Intel 852GM/852GMV GMCH only).
3.8.25. CAPD – Capability Disable Bits
Address Offset: F4h-F7h
Default Value: 00000000h
Access: Read/Write
Size: 32 bits
Bit Descriptions
31:12 Reserved
11:0 Capability Disable bits corresponding to Capability Register 39:28. This bit is logically ORed with the
corresponding strap and result of the “OR” is read through the capability register. Note that this register
cannot be used to enhance capability.
0 = Normal Operation.
1 = Forces Corresponding Capability to be disabled.
Register Description
R
76 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.9. Intel 852GM/852GMV GMCH Main Memory Control,
Memory I/O Control Registers (Device #0, Function #1)
The following table shows the Intel 852GM/852GMV GMCH configuration space for Device #0,
Function #1. See Section 3.2 for access nomenclature.
Table 19. Host-Hub I/F Bridge/System Memory Controller Configuration Space (Device #0,
Function#1)
Register Name Register
Symbol Register
Start Register
End Default Value Access
Vendor Identification VID 00 01 8086h RO
Device Identification DID 02 03 3584h RO
PCI Command Register PCICMD 04 05 0006h RO R/W
PCI Status Register PCISTS 06 07 0080h RO R/WC
Revision Identification RID 08 08 01h RO
Sub-Class Code SUBC 0A 0A 80h RO
Base Class Code BCC 0B 0B 08h RO
Header Type HDR 0E 0E 00h RO
Subsystem Vendor Identification SVID 2C 2D 0000h R/WO
Subsystem Identification SID 2E 2F 0000h R/WO
Capabilities Pointer CAPPTR 34 34 00h RO
DRAM Row 0-3 Boundaries DRB 0-3 40 43 00000000h RW
DRAM Row 0-3 Attributes DRA 0-3 50 51 7777h RW
DRAM Timing Register DRT 60 63 18004425h RW
DRAM Controller Power
Management Control Register
PWRMG 68 6B 00000000h R/W
Dram Controller Mode DRC 70 73 00000081h R/W
DRAM Throttle Control DTC A0 A3 00000000h R/W/L
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 77
3.9.1. VID – Vendor Identification
Address Offset: 00h
Default Value: 8086h
Access: Read Only
Size: 16 bits
The VID Register contains the vendor identification number. This 16-bit register combin ed with the
Device Identification Register un iquely identifies any PCI device. Writes to this register have no effect.
Bit Descriptions
15:0 Vendor Identification (VID): This register field contains the PCI standard identification for Intel, 8086h.
3.9.2. DID – Device Identification
Address Offset: 02h
Default Value: 3584h
Access: Read Only
Size: 16 bits
This 16-bit register combined with the Vendor Identification register uniquely identifies any PCI device.
Writes to this register have no effect.
Bit Descriptions
15:0 Device Identification Number (DID): This is a 16-bit value assigned to the Intel 852GM/852GMV GMCH
Host– HI Bridge Function #1.
Device ID Product Device ID
00 = Intel 852GM/852GMV GMCH 0x3584
01-11 = Reserved
Register Description
R
78 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.9.3. PCICMD – PCI Command Register
Address Offset: 04h
Default Value: 0006h
Access: Read Only, Read/Write
Size: 16 bits
Since Intel 852GM/852GMV Chipset Device #0 does not physically reside on PCI_A, many of the bits
are not implem ent e d.
Bit Descriptions
15:10 Reserved
9 Fast Back-to-Back Enable (FB2B): This bit controls whether or not the master can do fast back-to-back
write. Since Device #0 is strictly a target this bit is not implemented and is hardwired to 0. Writes to this
bit position have no affect.
Default Value= 0
8 SERR Enable (SERRE): SERR# is not implemented by Function #1 of Device #0 of the Intel
852GM/852GMV GMCH and this bit is hardwired to 0. Writes to this bit position have no effect.
Default Value = 0
7 Address/Data Stepping Enable (ADSTEP): Address/data stepping is not implemented in the Intel
852GM/852GMV GMCH, and this bit is hardwired to 0. Writes to this bit position have no effect.
Default Value = 0
6 Parity Error Enable (PERRE): PERR# is not implemented by Intel 852GM/852GMV GMCH and this bit
is hardwired to 0. Writes to this bit position have no effect.
Default Value = 0
5 VGA Palette Snoop Enable (VGASNOOP): The Intel 852GM/852GMV GMCH does not implement this
bit and it is hardwired to a 0. Writes to this bit position have no effect.
Default Value = 0
4 Memory Write and Invalidate Enable (MWIE): The Intel 852GM/852GMV GMCH will never issue
memory write and invalidate commands. This bit is therefore hardwired to 0. Writes to this bit position will
have no effect.
Default Value = 0
3 Special Cycle Enable (SCE): The Intel 852GM/852GMV GMCH does not implement this bit and it is
hardwired to a 0. Writes to this bit position have no effect.
Default Value = 0
2 Bus Master Enable (BME): The Intel 852GM/852GMV GMCH is always enabled as a master on HI.
This bit is hardwired to a “1”. Writes to this bit position have no effect.
Default Value = 1
1 Memor y Access Enable (M AE): The Intel 852GM/852GMV GMCH always allows access to main
System Memory. This bit is not implemented and is hardwired to 1. Writes to this bit position have no
effect.
Default Value = 1
0 I/O Access Enable (IOAE): This bit is not implemented in the Intel 852GM/852GMV GMCH and is
hardwired to a 0. Writes to this bit position have no effect.
Default Value = 0
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 79
3.9.4. PCISTS – PCI Status Register
Address Offset: 06h
Default Value: 0080h
Access: Read Only, Read/Write/Clear
Size: 16 bits
PCISTS is a 16-bit status register that reports the occurrence of error events on Device #0’s PCI
interface. Bit 14 is read/write clear. All other bits are Read Only. Since Intel 852GM/852GMV GMCH
Device #0 does not physically reside on PCI_A, many of the bits are not implemented.
Bit Descriptions
15 Detected Parity Error (DPE): The Intel 852GM/852GMV GMCH does not implement this bit and it is
hardwired to a 0. Writes to this bit position have no effect.
Default Value = 0
14 Signaled System Error (SSE): The Intel 852GM/852GMV GMCH does not implement this bit and it is
hardwired to a 0. Writes to this bit position have no effect.
Default Value = 0
13 Received Master Abort Status (RMAS): The Intel 852GM/852GMV GMCH does not implement this bit
and it is hardwired to a 0. Writes to this bit position have no effect.
Default Value = 0
12 Received Target Abort Status (RTAS): The Intel 852GM/852GMV GMCH does not implement this bit
and it is hardwired to a 0. Writes to this bit position have no effect.
Default Value = 0
11 Signaled Target Abort Status (STAS): The Intel 852GM/852GMV GMCH does not implement this bit
and it is hardwired to a 0. Writes to this bit position have no effect.
Default Value = 0
10:9 DEVSEL Timing (DEVT): These bits are hardwired to “00”. Writes to these bit positions have no affect.
Device 0 does not physically connect to PCI_A. These bits are set to “00” (fast decode) so that the Intel
852GM/852GMV GMCH does not limit optimum DEVSEL timing for PCI_A.
Default Value = 0
8 Master Data Parity Error Detected (DPD): The Intel 852GM/852GMV GMCH does not implement this
bit and it is hardwired to a 0. Writes to this bit position have no effect.
Default Value = 0
7 Fast Back-to-Back (FB2B): This bit is hardwired to 1. Writes to these bit positions have no effect.
Device 0 does not physically connect to PCI_A. This bit is set to 1 (indicating fast back-to-back capability)
so that the Intel 852GM/852GMV GMCH does not limit the optimum setting for PCI_A.
Default Value = 1
6:5 Reserved
4 Capability List (CLIST): This bit is hardwired to 0 to indicate to the configuration software that this
device/function does not implement new capabilities.
Default Value = 0
3:0 Reserved
Register Description
R
80 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.9.5. RID – Revision Identification
Address Offset: 08h
Default Value: 01h
Access: Read Only
Size: 8 bits
This register contains th e revision number of the Intel 852GM/852GMV GMCH Device #0. These b its
are read only and writes to this register have no effect.
Bit Descriptions
7:0 Revision Identification Number (RID): This is an 8-bit value that indicates the revision identification
number for the Intel 852GM/852GMV GMCH Device #0.
3.9.6. SUBC – Sub-Class Code
Address Offset: 0Ah
Default Value: 80h
Access: Read Only
Size: 8 bits
This register contains the Sub-Class Code for the Intel 852GM/852GMV GMCH Device #0. This code
is 80h indicating Other Peripheral device.
Bit Descriptions
7:0 Sub-Class Code (SUBC): This is an 8-bit value that indicates the category of Peripheral device into
which the Intel 852GM/852GMV GMCH Function #1 falls. The code is 80h indicating Other Peripheral
device.
3.9.7. BCC – Base Class Code
Address Offset: 0Bh
Default Value: 08h
Access: Read Only
Size: 8 bits
This register contains the Base Class Code of the Intel 852GM/852GMV GMCH Device #0 Function #1.
This code is 08h indicating Other Peripheral device.
Bit Descriptions
7:0 Base Class Code (BASEC): This is an 8-bit value that indicates the Base Class Code for the Intel
852GM/852GMV GMCH. This code has the value 08h, indicating Other Peripheral device.
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 81
3.9.8. HDR – Header Type
Address Offset: 0Eh
Default Value: 80h
Access: Read Only
Size: 8 bits
This register identifies the header layout of the configuration space. No physical register exists at this
location.
Bit Descriptions
7:0 PCI Header (HDR): This field always returns 80 to indicate that Device #0 is a multifunction device. The
default is 80 Reads and writes to this location have no effect.
3.9.9. SVID – Subsystem Vendor Identification
Address Offset: 2Ch
Default Value: 0000h
Access: Write Once
Size: 16 bits
This value is used to identify the vendor of the subsystem.
Bit Descriptions
15:0 Subsystem Vendor ID (SUBVID): This field should be programmed during boot-up to indicate the vendor of
the system board. After it has been written once, it becomes read only.
3.9.10. SID – Subsystem Identification
Address Offset: 2Eh
Default Value: 0000h
Access: Write Once
Size: 16 bits
This value is used to identify a particular subsystem.
Bit Descriptions
15:0 Subsystem ID (SUBID): This field should be programmed during BIOS initialization. After it has been written
once, it becomes read only.
Register Description
R
82 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.9.11. CAPPTR – Capabilities Pointer
Address Offset: 34h
Default Value: 00h
Access: Read Only
Size: 8 bits
The CAPPTR provides the offset that is the pointer to the location of the first device capability in the
capability list.
Bit Descriptions
7:0 Pointer to the offset of the first capability ID register block: In this case there are no capabilities,
therefore these bits are hardwired to 00h to indicate the end of the capability linked list.
3.9.12. DRB – DRAM Row Boundary Register - Device #0
Address Offset: 40-43h
Default Value: 00h Each
Access: Read/Write
Size: 8 bits
The DDR SDRAM Row Boundary Register defines the upper boundary address of each DDR
SDRAM row with a granularity of 32-MB. Each row has its own single-byte DRB register. For
example, a value of 1 in DRB0 indicates that 32-MB of DDR SD RAM has been populated in the first
row. Since Intel 852GM/852GMV GMCH supports a total of 4 rows of System Memory, DRB0-3 are
used. The registers from 44h-4Fh are reserved for DRBs 4-15.
Row0: 40h
Row1: 41h
Row2: 42h
Row3: 43h
44h to 4F is reserved.
DRB0 = Total System Memory in row0 (in 32 -MB increments)
DRB1 = Total System Memory in row0 + row1 (in 32 -MB increments)
DRB2 = Total System Memory in row0 + row1 + row2 (in 32 -MB increments)
DRB3 = Total System Memory in row0 + row1 + row2 + row3 (in 32- MB increments)
Each Row is represented by a byte. Each byte h as the following format.
Bit Description
7:0 DDR SDRAM Row Boundary Address: This 8-bit value defines the upper and lower addresses for each DDR
SDRAM row. This 8-bit value is compared against a set of address lines to determine the upper address limit
of a particular row. Also the minimum System Memory supported is 64-MB in 64-Mb granularity; hence bit 0 of
this register must be programmed to a zero.
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 83
3.9.13. DRA – DRAM Row Attribute Register - Device #0
Address Offset: 50-51h
Default Value: 77h Each
Access: Read/Write
Size: 8 bits
The DDR SDRAM Row Attribute Register defines the page sizes to be used when accessing different
pairs of rows. Each nibble of information in the DRA registers describes the page size of a pair of rows:
Row0, 1: 50h
Row2, 3: 51h
52h-5Fh: Reserved.
7 6 4 3 2 0
R Row attribute for Row1 R Row Attribute for Row0
7 6 4 3 2 0
R Row attribute for Row3 R Row Attribute for Row2
Bit Description
7 Reserved
6:4 Row Attribute for odd-numbered row: This field defines the page size of the corresponding row.
000: Reserved
001: 4 kB
010: 8 kB
011: 16 kB
111: Not Populated
Others: Reserved
3 Reserved
2:0 Row Attribute for even-numbered row: This field defines the page size of the corresponding row.
000: Reserved
001: 4 kB
010: 8 kB
011: 16 kB
111: Not Populated
Others: Reserved
Register Description
R
84 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.9.14. DRT – DRAM Timing Register - Device #0
Address Offset: 60-63h
Default Value: 18004425h
Access: Read/Write
Size: 32 bits
This register controls the timing of the DDR SDRAM Controller.
Bit Description
31 DDR Internal Write to Read Comman d delay (tWTR):
The tWTR is a std. DDR SDRAM timing parameter with a value of 1 CK for CL=2 and 2.5. The tWTR is used
to time RD command after a WR command (to same row):
‘0’: tWTR is set to 1 Clock (CK), used for DDR SDRAM CL=2 or 2.5
‘1’: Reserved
30 DDR Write Recovery time (tWR):
Write recovery time is a std. DDR timing parameter with the value of 15 ns. It should be set to 2 CK when
DDR200 is used. The tWR is used to time PRE command launch after a WR command, when DDR SDRAM
components are populated.
‘0’: tWR is set to 2 Clocks (CK)
‘1’: tWR is set to 3 Clocks (CK)
29:28 Back To Back Write-Read commands spacing (DDR different rows/bank):
This field determines the WR-RD command spacing, in terms of common clocks for DDR SDRAM based on
the following formula: DQSS + 0.5xBL + TA (wr-rd) – CL
DQSS: is time from write command to data and is always 1 CK
BL: is burst length and can be set to 4.
TA (wr-rd): is required DQ turn-around, can be set to 1 or 2 CK
CL: is CAS latency, can be set to 2 or 2.5
Examples of usage:
For BL=4, with single DQ turn-around and CL=2, this field must be set to 2 CK (1+2+1-2)
Encoding CK between WR and RD commands
BL=4
00: 4
01: 3
10: 2
11: Reserved
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 85
Bit Description
27:26 Back To Back Read-Write commands spacing (DDR, same or different rows/bank): This field determines
the RD-WR command spacing, in terms of common clocks based on the following formula: CL + 0.5xBL + TA
(rd-wr) – DQSS
DQSS: is time from write command to data and is always 1 CK
BL: is burst length which is set to 4
TA (rd-wr): is required DQ turn-around, can be set to 1, 2 or 3 CK
CL: is CAS latency, can be set to 2 or 2.5
Examples of usage:
For BL=4, with single DQ turn-around and CL=2, this field must be set to 4 CK (2+2+1-1)
Encoding CK be tween RD and WR commands
BL=4
00: 7
01: 6
10: 5
11: 4
NOTES:
Since reads in DDR SDRAM cannot be terminated by writes, the space between commands is not a function
of cycle length but of burst length.
25 Back To Back Read-Read commands spacing (DDR, different rows):
This field determines the RD-RD command spacing, in terms of common clocks based on the following
formula: 0.5xBL + TA(rd-rd)
BL: is burst length and can be set to 4.
TA (rd-rd): is required DQ turn-around, can be set to 1 or 2 CK
Examples of usage:
For BL=4, with single DQ turn-around, this field must be set to 3 CK (2+1)
Encoding CK be tween RD and RD commands
BL=4
0: 4
1: 3
NOTES:
Since a read to a different row doesn’t terminate a read, the space between commands is not a function of
cycle length but of burst length.
24:15 Reserved
Register Description
R
86 Intel
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852GM/852GMV Chipset GMCH Data sheet
Bit Description
14:12 Refresh Cycle Time (tRFC):
Refresh cycle time is measured for a given row from REF command (to perform a refresh) until following ACT
to same row (to perform a read or write). It is tracked separately from tRC for DDR SDRAM.
Current DDR SDRAM spec requires tRFC of 75 ns (DDR266) and 80nS (DDR200). Therefore, this field will
be set to 8 clocks for DDR200, 10 clocks for DDR266.
Encoding tRFC
“000”: 14 clocks
“001”: 13 clocks
“010”: 12 clocks
“011”: 11 clocks
“100”: 10 clocks
“101”: 9 clocks
“110”: 8 clocks
“111”: 7 clocks
11 Activate to Precharge delay (tRAS), MAX:
This bit controls the maximum number of clocks that a DDR SDRAM bank can remain open. After this time
period, the System Memory controller will guarantee to pre-charge the bank. Note that this time period may
or may not be set to overlap with time period that requires a refresh to happen.
The DDR SDRAM controller includes a separate tRAS-MAX counter for every supported bank. With a
maximum of four row and four banks per row, there are 16 counters.
‘0’: 120 micro-seconds
‘1’: Reserved.
10:9 Activate to Precharge delay (tRAS), MIN:
This bit controls the number of DDR SDRAM clocks for tRAS MIN
00: 8 Clocks
01: 7 Clocks
10: 6 Clocks
11: 5 Clocks
8:7 Reserved
6:5 CAS# Latency (tCL):
Encoding DDR SDRAM CL
00: 2.5
01: 2
10: Reserved
11: Reserved
4 Reserved
3:2 DDR SDRAM RAS# to CAS# Delay (tRCD): This bit controls the number of clocks inserted between a row
activate command and a read or write command to that row
Encoding tRCD
00: Reserved
01: 3 DDR SDRAM Clocks
10: 2 DDR SDRAM Clocks
11: Reserved
Register Description
R
Intel
®
852GM/852GMV Chipset GMCH Datasheet 87
Bit Description
1:0 DDR SDRAM RAS# Precharge (tRP): This bit controls the number of clocks that are inserted between a row
precharge command and an activate command to the same row
Encoding tRP
00: Reserved
01: 3 DDR SDRAM Clocks
10: 2 DDR SDRAM Clocks
11: Reserved
3.9.15. PWRMG – DRAM Controller Power Management Control
Register - Device #0
Address Offset: 68h-6Bh
Default Value: 00000000h
Access: Read/Write
Size: 32 bits
Bit Description
31:24 Reserved
23:20 Row State Control: This field determines the number of clocks the DDR SDRAM controller will retain in
the idle state before it begins pre-charging all pages or powering down rows.
PDEn: Power Down Enable
PCEn: Page Close Enable
TC: Timer Control
PDEn(23): PCEn(22): TC(21:20)Function
0 0 XX All disabled
0 1 XX Reserved
1 0 XX Reserved
1 1 0X Reserved
10 Reserved
11 Precharge and Power Down after 64 DDR SDRAM
Clocks of idle time
19:0
Register Description
R
88 Intel
®
852GM/852GMV Chipset GMCH Data sheet
3.9.16. DRC – DRAM Controller Mode Register - Device #0
Address Offset: 70-73h
Default Value: 00000081h
Access: Read/Write, read-only
Size: 32 bits
Bit Description
31:30
Revision Number (REV): Reflects the revision number of the format used for DDR SDRAM register
definition.
29 Initialization Complete (IC): This bit is used for communication of software state between the memory
controller and the BIOS. BIOS sets this bit to 1 after initialization of the DDR SDRAM memory array is
complete. Setting this bit to a “1” enables DDR SDRAM refreshes. On power up and S3 exit, the BIOS
initializes the DDR SDRAM array and sets this bit to a “1”. This bit works in combination with the RMS bits in
controlling refresh state:
IC Refresh State
0 OFF
1 ON
28:24 Reserved
23:22 Number of Channels (CHAN): Reflects that Intel 852GM/852GMV GMCH supports only one System
Memory channel.
00 One channel is populated appropriately
Others: Reserved
21:20 DDIM DDR SDRAM Data Integrity Mode:
No-ECC. No read-merge-write on partial writes. ECC data sense-amps are disabled and the data output is
tristate. (Default)
19:16 Reserved
15 RAS Lock-Out Enable: Set to a ‘1’ if all populated rows support RAS Lock-Out. Defaults to ‘0’.
If this bit is set to a ‘1’ the DDR SDRAM controller assumes that the DDR SDRAM guarantees tRAS min
before an auto precharge (AP) completes (Note that an AP is sent with a read or a write command). Also, the
DDR SDRAM controller does not issue an activate command to the auto pre-charged bank for tRP.
If this bit is set to a ‘0’ the DDR SDRAM controller does not schedule an AP if tRAS min is not met.
14:10 Reserved
9:7 Refresh Mode Select (RMS): This field determines whether refresh is enabled and, if so, at what rate
refreshes will be executed.
000: Refresh disabled
001: Refresh enabled. Refresh interval 15.6 µsec
010: Refresh enabled. Refresh interval 7.8 µsec
011: Reserved.
111: Refresh enabled. Refresh interval 64 clocks (fast refresh mode)
Other: Reserved
Any change in the programming of this field resets the refresh counter to zero. This function is for testing
purposes, it allows test program to align refresh events with the test and thus improve failure repeatability.
6:4 Mode Select (SMS). These bits select the special operational mode of the DDR SDRAM interface. The
special modes are intended for initialization at power up.
000: Post Reset state – When the Intel 852GM/852GMV GMCH exits reset (power-up or otherwise), the
mode select field is cleared to “000”. Software not expected to write this value, however if this value is
written there are no side effects (no self refresh or any other special DDR SDRAM cycle).
During any reset sequence, while power is applied and reset is active, the Intel 852GM/852GMV GMCH
deasserts all CKE signals. After internal reset is deasserted, CKE signals remain deasserted until this field is
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 89
Bit Description
written to a value different than “000”. On this event, all CKE signals are asserted.
During suspend (S3, S4), Intel 852GM/852GMV GMCH internal signal triggers DDR SDRAM controller to
flush pending commands and enter all rows into Self-Refresh mode. As part of resume sequence, Intel
852GM/852GMV GMCH will be reset – which will clear this bit field to “000” and maintain CKE signals
deasserted. After internal reset is deasserted, CKE signals remain deasserted until this field is written to a
value different than “000”. On this event, all CKE signals are asserted.
During entry to other low power states (C3, S1-M), Intel 852GM/852GMV GMCH internal signal triggers DDR
SDRAM controller to flush pending commands and enter all rows in S1 and relevant rows in C3 (Based on
RPDNC3) into Self-Refresh mode. During exit to normal mode, the GMCH signal triggers DDR SDRAM
controller to exit Self-Refresh and resume normal operation without S/W involvement.
001: NOP Command Enable – All CPU cycles to DDR SDRAM result in a NOP command on the DDR
SDRAM interface.
010: All Banks Pre-charge Enable – All CPU cycles to DDR SDRAM result in an “all banks precharge”
command on the DDR SDRAM interface.
011: Mode Register Set Enable – All CPU cycles to DDR SDRAM result in a “mode register” set command
on the DDR SDRAM interface. Host address lines are mapped to DDR SDRAM address lines in order to
specify the command sent. Host address HA[13:3] are mapped to memory address MA[11, 9:0]. MA3 must
be driven to 1 for interleave wrap type.
For Double Data Rate
MA[6:4] needs to be driven based on the value programmed in the CAS# Latency field.
CAS Latency MA[6:4]
1.5 Clocks 001
2.0 Clocks 010
2.5 Clocks 110
MA[7] should always be driven to a 0.
MA[8] Should be driven to a 1 for DLL Reset and 1 for Normal Operation.
MA[12:9] must be driven to 00000.
BIOS must calculate and drive the correct host address for each row of memory such that the correct
command is driven on the MA[12:0] lines. Note that MAB[7:4]# are inverted from MAA[7:4]; BIOS must
account for this.
100: Extended Mode Register Set Enable – All CPU cycles to DDR SDRAM result in an “extended mode
register set” command on the DDR SDRAM interface. Host address lines are mapped to DDR SDRAM
address lines in order to specify the command sent. Host address lines are mapped to DDR SDRAM address
lines in order to specify the command sent. Host address HA[13:3] are mapped to memory address [9:0].
MA[0] = 0 for DLL enable and 1 for DLL disable. All the other MA lines are driven to 0s. Note that MAB[7:4]#
are inverted from MAA[7:4]; BIOS must account for this.
101: Reserved
110: CBR Refresh Enable – In this mode all CPU cycles to DDR SDRAM result in a CBR cycle on the DDR
SDRAM interface
111: Normal operation
3:0
Reserved
Register Description
R
90 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.9.17. DTC – DRAM Throttling Control Register (Device 0)
Offset Address: A0–A3h
Default Value: 00000000h
Access: Read/Write/Lock
Size: 32 bits
Throttling is independent for System Memory Banks, Intel 852GM/852GMV GMCH Writes, and
thermal sensor trips. Read and Write Bandwidth is measured independently for each Bank. If the number
of Octal -Words (16 bytes) read/written during the window defined below (Global DDR SDRAM
Sampling Window: GDSW) exceeds the DDR SDRAM Bandwidth Threshold, then the DDR SDRAM
throttling mechanism will be invoked to limit DDR SDRAM reads/writes to a lower bandwidth checked
over smaller time windows. The throttling will be active for the remainder of the current GDSW and for
the next GDSW after which it will return to non-throttling mode. The throttling mechanism accounts for
the actual bandwidth consumed during the sampling window, by reducing the allowed bandwidth within
the smaller throttling window based on the bandwidth consumed during the sampling period. Although
bandwidth from/to independent rows and Intel 852GM/852GMV GMCH write bandwidth is measured
independently, once tripped all transactions except high priority graphics reads are subject to throttling.
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 91
Bit Description
31:28 DDR SDRAM Throttle Mode (TMODE):
Four bits control which mechanisms for throttling are enabled in an “OR” fashion. Counter-based
throttling is lower priority than thermal trips throttling when both are enabled and tripped. Counter-based
trips point throttling values and Thermal-based trip point throttling values are specified in this register.
If the counter and thermal mechanisms for either rank or Intel 852GM/852GMV GMCH are both enabled,
throttle settings for the one that trips first is used until the end of the second gdsw.
[Rank Counter, Intel 852GM/852GMV GMCH Write Counter, Rank Thermal Sensor, Intel
852GM/852GMV GMCH Thermal Sensor]
0000 = Throttling turned off. This is the default setting. All Counters are off.
0001 = Only Intel 852GM/852GMV GMCH Thermal Sensor based throttling is enabled. If Intel
852GM/852GMV GMCH thermal sensor is tripped, write throttling begins based on the setting in WTTC.
0010 = Only Rank Thermal Sensor based throttling enabled. When the external SO-DIMM thermal
sensor is tripped DDR SDRAM throttling begins based on the setting in RTTC.
0011 = Both Rank and Intel 852GM/852GMV GMCH Thermal Sensor based throttling enabled. When
the external SO-DIMM thermal sensor is tripped DDR SDRAM throttling begins based on the setting in
RTTC. If the Intel 852GM/852GMV GMCH thermal sensor is tripped, write throttling begins based on the
setting in WTTC.
0100 = Only the Intel 852GM/852GMV GMCH Write Counter mechanism is enabled. When the
threshold set in the GDT field is reached, DDR SDRAM throttling begins based on the setting in WCTC.
0101 = Intel 852GM/852GMV GMCH Thermal Sensor and Intel 852GM/852GMV GMCH Write DDR
SDRAM Counter mechanisms are both enabled. If the Intel 852GM/852GMV GMCH write DDR
SDRAM counter mechanism threshold is reached, DDR SDRAM throttling begins based on the setting in
WCTC. If the Intel 852GM/852GMV GMCH thermal sensor is tripped, DDR SDRAM throttling begins
based on the setting in WTTC. If both threshold mechanisms are tripped, the DDR SDRAM throttling
begins based on the settings in WTTC.
0110 = Rank Thermal Sensor and Intel 852GM/852GMV GMCH Write DDR SDRAM Counter
mechanisms are both enabled. If the Intel 852GM/852GMV GMCH write DDR SDRAM counter
mechanism threshold is reached, DDR SDRAM throttling begins based on setting in WCTC. If the
external SO-DIMM thermal sensor is tripped, Rank DRAM throttling begins based on the setting in
RTTC.
0111 = Similar to 0101 for writes and when the Rank thermal sensor is tripped DDR SDRAM throttling
begins based on the setting in RTTC.
1000 = Only Rank Counter mechanism is enabled. When the threshold set in the GDT field is reached,
DDR SDRAM throttling begins based on the setting in RCTC.
1001 = Rank Counter mechanism is enabled and Intel 852GM/852GMV GMCH Thermal Sensor
based throttling are both enabled. If Intel 852GM/852GMV GMCH thermal sensor is tripped, write
throttling begins based on the setting in WTTC. When the threshold set in the GDT field is reached, DDR
SDRAM throttling begins based on the setting in RCTC.
1010 = Rank thermal Sensor and Rank DDR SDRAM Counter mechanisms are both enabled. If the
rank DDR SDRAM counter mechanism threshold is reached, DDR SDRAM throttling begins based on
the setting in RCTC. If the external SO-DIMM thermal sensor is tripped, DRAM throttling begins based
on the setting in RTTC.
1011 = Similar to 1010 and If the Intel 852GM/852GMV GMCH thermal sensor is tripped, write
throttling begins based on the setting in WTTC.
1111 = Rank and Intel 852GM/852GMV GMCH Thermal Sensor based throttling and Rank and Intel
852GM/852GMV GMCH Write Counter based throttling are enabled. If both the write counter and Intel
852GM/852GMV GMCH thermal sensor based mechanisms are tripped, DDR SDRAM throttling begins
based on the setting allowed in WTTC. If both the rank counter and rank thermal sensor based
mechanisms are tripped, DDR SDRAM throttling begins based on the setting allowed in RTTC.
27:24 Read Counter Based Power Throttle Control (RCTC): These bits select the Counter based Power
Throttle Bandwidth Limits for Read operations to System Memory.
Register Description
R
92 Intel
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852GM/852GMV Chipset GMCH Data sheet
Bit Description
R/W, RO if Throttle Lock.
0h = 85%
1h = 70%
2h = 65%
3h = 60%
4h = 55%
5h = 50%
6h = 45%
7h = 40%
8h = 35%
9h = 30%
Ah = 20%
B-Fh = Reserved
23:20 Write Counter Based Power Throttle Control (WCTC): These bits select the Counter based Power
Throttle Bandwidth Limits for Write operations to System Memory.
R/W, RO if Throttle Lock
0h = 85%
1h = 70%
2h = 65%
3h = 60%
4h = 55%
5h = 50%
6h = 45%
7h = 40%
8h = 35%
9h = 30%
Ah = 20%
B-Fh = Reserved
19:16 Read Thermal Based Power Throttle Control (RTTC): These bits select the thermal sensor based
Power Throttle Bandwidth Limits for Read operations to System Memory.
R/W, RO if Throttle Lock.
0h = 85%
1h = 70%
2h = 65%
3h = 60%
4h = 55%
5h = 50%
6h = 45%
7h = 40%
8h = 35%
9h = 30%
Ah = 20%
B-Fh = Reserved
15:12 Write Thermal Based Power Throttle Control (WTTC): These bits select the thermal based Power
Throttle Bandwidth Limits for Write operations to System Memory.
R/W, RO if Throttle Lock
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 93
Bit Description
0h = 85%
1h = 70%
2h = 65%
3h = 60%
4h = 55%
5h = 50%
6h = 45%
7h = 40%
8h = 35%
9h = 30%
Ah = 20%
B-Fh = Reserved
11 Cou nter Based Thro ttle Lock (C TL OCK ): This bit secures RCTC and WCTC. This bit defaults to 0.
Once a 1 is written to this bit, RCTC and WCTC (including CTLOCK) become read-only.
10 Thermal Throttle Lock (TTLOCK): This bit secures the DDR SDRAM throttling control register. This bit
defaults to 0. Once a 1 is written to this bit, all of the configuration register bits in DTC (including
TTLOCK) except CTLOCK, RCTC and WCTC become read-only.
9 Thermal Power Throttle Control fields Enable:
0 = RTTC and WTTC are not used. RCTC and WTCT are used for both counter and thermal based
throttling.
1 = RTTC and WTTC are used for thermal based throttling.
8 High Priority Stream Throttling Enable :
Normally High Priority Streams are not throttled when either the counter based mechanism or thermal
sensor mechanism demands throttling.
0 = Normal operation.
1 = Block High priority streams during throttling.
7:0 Global DDR SDRAM Sampling Window (GDSW): This 8-bit value is multiplied by 4 to define the length
of time in milliseconds (0–1020) over which the number of Octal Words (16 bytes) read/written is
counted and throttling is imposed. Note that programming this field to “00h” disables System Memory
throttling.
Recommended values are between 0.25 and 0.75 seconds.
Register Description
R
94 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.10. Intel 852GM/852GMV GMCH Configuration Process and
Registers (Device #0, Function #3)
See Section 3.2 for access nomenclature. Table 20 summarizes all Device#0, Function #3 registers.
Table 20. Configuration Process Configuration Space (Device#0, Function #3)
Register Name Register
Symbol Register
Start Register
End Default Value Access
Vendor Identification VID 00 01 8086h RO
Device Identification DID 02 03 3585 RO
PCI Command Register PCICMD 04 05 0006h RO R/W
PCI Status Register PCISTS 06 07 0080h RO R/WC
Revision Identification RID 08 08 01h RO
Sub-Class Code SUBC 0A 0A 80h RO
Base Class Code BCC 0B 0B 08h RO
Header Type HDR 0E 0E 80h RO
Subsystem Vendor Identification SVID 2C 2D 0000h R/WO
Subsystem Identification SID 2E 2F 0000h R/WO
Capabilities Pointer CAPPTR 34 34 00h RO
HPLL Clock Control Register HPLLCC C0 C1 00h RO
3.10.1. VID – Vendor Identification
Address Offset: 00h
Default Value: 8086h
Access: Read Only
Size: 16 bits
The VID Register contains the vendor identification number. This 16-bit register combined with the
Device Identification Register un iquely identifies any PCI device. Writes to this register have no effect.
Bit Descriptions
15:0 Vendor Identification (VID): This register field contains the PCI standard identification for Intel 8086h.
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 95
3.10.2. DID – Device Identification
Address Offset: 02h
Default Value: 3585h
Access: Read Only
Size: 16 bits
This 16-bit register combined with the Vendor Identification register uniquely identifies any PCI device.
Writes to this register have no effect.
Bit Descriptions
15:0 Device Identification Number (DID): This is a 16-bit value assigned to the Intel 852GM/852GMV GMCH
Host-HI Bridge Function #3.
Product Device ID
00 = Intel 852GM/852GMV GMCH (Default) = 3585h
01-11 = Reserved
Register Description
R
96 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.10.3. PCICMD – PCI Command Register
Address Offset: 04h
Default Value: 0006h
Access: Read Only, Read/Write
Size: 16 bits
Since Intel 852GM / 85 2 GM V GM CH Device #0 does not physically reside on PCI_A many of the bits
are not implem ent e d.
Bit Descriptions
15:10 Reserved
9 Fast Back-to-Back Enable (FB2B): This bit controls whether or not the master can do fast back-to-back
write. Since device 0 is strictly a target this bit is not implemented and is hardwired to 0. Writes to this bit
position have no affect.
8 SERR Enable (SERRE): SERR# is not implemented by Function 1 of Device 0 of the Intel 852GM/852GMV
GMCH and this bit is hardwired to 0. Writes to this bit position have no effect.
7 Address/Data Stepping Enable (ADSTEP): Address/data stepping is not implemented in the Intel
852GM/852GMV GMCH, and this bit is hardwired to 0. Writes to this bit position have no effect.
6 Parity Error Enable (PERRE): PERR# is not implemented by Intel 852GM/852GMV GMCH and this bit is
hardwired to 0. Writes to this bit position have no effect.
5 VGA Palette Snoop Enable (VGASNOOP): The Intel 852GM/852GMV GMCH does not implement this bit
and it is hardwired to a 0. Writes to this bit position have no effect.
4 Memory Write and Invalidate Enable (MWIE): The Intel 852GM/852GMV GMCH will never issue memory
write and invalidate commands. This bit is therefore hardwired to 0. Writes to this bit position will have no
effect.
3 Special Cycle Enable (SCE): The Intel 852GM/852GMV GMCH does not implement this bit and it is
hardwired to a 0. Writes to this bit position have no effect.
2 Bus Master Enable (BME): The Intel 852GM/852GMV GMCH is always enabled as a master on HI. This
bit is hardwired to a "1". Writes to this bit position have no effect.
1 Memor y Access Enable (M AE): The Intel 852GM/852GMV GMCH always allows access to main memory.
This bit is not implemented and is hardwired to 1. Writes to this bit position have no effect.
0 I/O Access Enable (IOAE): This bit is not implemented in the Intel 852GM/852GMV GMCH and is
hardwired to a 0. Writes to this bit position have no effect.
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 97
3.10.4. PCISTS – PCI Status Register
Address Offset: 06h
Default Value: 0080h
Access: Read Only, Read/Write/Clear
Size: 16 bits
PCISTS is a 16-bit status register that reports the occurrence of error events on Device #0’s PCI
interface. Bit 14 is read/write clear. All other bits are Read Only. Since Intel 852GM/852GMV GMCH
Device #0 does not physically reside on PCI_A many of the bits are not implemented.
Bit Descriptions
15 Detected Parity Error (DPE): The Intel 852GM/852GMV GMCH does not implement this bit and it is
hardwired to a 0. Writes to this bit position have no effect.
14 Signaled System Error (SSE): The Intel 852GM/852GMV GMCH does not implement this bit and it is
hardwired to a 0. Writes to this bit position have no effect.
13 Received Master Abort Status (RMAS): The Intel 852GM/852GMV GMCH does not implement this bit
and it is hardwired to a 0. Writes to this bit position have no effect.
12 Received Target Abort Status (RTAS): The Intel 852GM/852GMV GMCH does not implement this bit and
it is hardwired to a 0. Writes to this bit position have no effect.
11 Signaled Target Abort Status (STAS): The Intel 852GM/852GMV GMCH does not implement this bit and
it is hardwired to a 0. Writes to this bit position have no effect.
10:9 DEVSEL Timing (DEVT): These bits are hardwired to "00". Writes to these bit positions have no affect.
Device #0 does not physically connect to PCI_A. These bits are set to "00" (fast decode) so that the Intel
852GM/852GMV GMCH does not limit optimum DEVSEL timing for PCI_A.
8 Master Data Parity Error Detected (DPD): The Intel 852GM/852GMV GMCH does not implement this bit
and it is hardwired to a 0. Writes to this bit position have no effect.
7 Fast Back-to-Back (FB2B): This bit is hardwired to 1. Writes to these bit positions have no effect. Device
#0 does not physically connect to PCI_A. This bit is set to 1 (indicating fast back-to-back capability) so that
the Intel 852GM/852GMV GMCH does not limit the optimum setting for PCI_A.
6:5 Reserved
4 Capability List (CLIST): This bit is hardwired to 0 to indicate to the configuration software that this
device/function does not implement new capabilities.
3:0 Reserved
Register Description
R
98 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.10.5. RID – Revision Identification
Address Offset: 08h
Default Value: 01h
Access: Read Only
Size: 8 bits
This register contains the revision number of the Intel 852GM/852GMV GMCH. These bits are read
only and writes to this register have no effect.
Bit Descriptions
7:0 Revision Identification Number (RID): This is an 8-bit value that indicates the revision identification
number for the Intel 852GM/852GMV GMCH.
3.10.6. SUBC – Sub-Class Code
Address Offset: 0Ah
Default Value: 80h
Access: Read Only
Size: 8 bits
This register contains the Sub-Class Code for the Intel 852GM/852GMV GMCH Device #0. This code
is 80h indicating a peripheral device.
Bit Descriptions
7:0 Sub-Class Code (SUBC): This is an 8-bit value that indicates the category of Bridge into which the Intel
852GM/852GMV GMCH falls. The code is 80h indicating other peripheral device.
3.10.7. BCC – Base Class Code
Address Offset: 0Bh
Default Value: 08h
Access: Read Only
Size: 8 bits
This register contains the Base Class Code of the Intel 852GM/852GMV GMCH Device #0 Function #3.
This code is 08h indicating a peripheral device.
Bit Descriptions
7:0 Base Class Code (BASEC): This is an 8-bit value that indicates the Base Class Code for the Intel
852GM/852GMV GMCH. This code has the value 08h, indicating other peripheral device.
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 99
3.10.8. HDR – Header Type
Address Offset: 0Eh
Default Value: 080h
Access: Read Only
Size: 8 bits
This register identifies the header layout of the configuration space. No physical register exists at this
location.
Bit Descriptions
7:0 PCI Header (HDR): This field always returns 80 to indicate that Device 0 is a multifunction device. If
Functions other than #0 are disabled this field returns a 00 to indicate that the Intel 852GM/852GMV GMCH
is a single function device with standard header layout. The default is 80 Reads and writes to this location
have no effect.
3.10.9. SVID – Subsystem Vendor Identification
Address Offset: 2Ch
Default Value: 0000h
Access: Write Once
Size: 16 bits
This value is used to identify the vendor of the subsystem.
Bit Descriptions
15:0 Subsystem Vendor ID (SUBVID): This field should be programmed during boot-up to indicate the vendor of
the system board. After it has been written once, it becomes read only.
3.10.10. ID – Subsystem Identification
Address Offset: 2Eh
Default Value: 0000h
Access: Write Once
Size: 16 bits
This value is used to identify a particular subsystem.
Bit Descriptions
15:0 Subsystem ID (SUBID): This field should be programmed during BIOS initialization. After it has been written
once, it becomes read only.
Register Description
R
100 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.10.11. CAPPTR – Capabilities Pointer
Address Offset: 34h
Default Value: 00h
Access: Read Only
Size: 8 bits
The CAPPTR provides the offset that is the pointer to the location of the first device capability in the
capability list.
Bit Descriptions
7:0 Pointer to the offset of the first capabilit y ID register block: In this case there are no capabilities
therefore these bits are hardwired to 00h to indicate the end of the capability-linked list.
3.10.12. HPLLCC – HPLL Clock Control Register (Device 0)
Address Offset: C0–C1h
Default Value: 00h
Access: Read Only
Size: 16 bits
Bit Descriptions
15:11 Reserved
10 HPLL VCO Change Sequence Initiate Bit:
Software must write a '0' to clear this bit and then write a '1' to initiate sequence again.
9 Hphase Reset Bit:
1 = Assert
0 = Deassert (default)
8 Reserved
7:2 Reserved
1:0 HPLL Clock Control:
Software is allowed to update this register.
See Table 21 for Clock definitions.
Table 21. Intel 852GM/852GMV GMCH Configurations
Straps Read Through
HPLLCC[1:0]: D0:F3 :Register
Offset C0-C1h, bits[1:0 ]
FSB Frequenc y System Memory
Frequency GFX Core
Clock(Low) GFX Core
Clock (High)
00 400 MHz 266 MHz 133 MHz 133 MHz
10 400 MHz 200 MHz 133 MHz 133 MHz
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 101
3.11. Intel 852GM/852GMV GMCH Integrated Graphics
Device Registers (Device #2, Function #0)
This section contains the PCI configuration registers listed in order of ascending offset address. Device
#2 incorporates Function #0. See Section 3.2 for access nomenclature.
Table 22. Integrated Graphics Device Configuration Space (Device #2, Function#0)
Register Name Register
Symbol Address
Offset Register
End Default
Value Access Regs in
Function#1
Vendor Identification VID2 00h 01h 8086h RO C0F0
Device Identification DID2 02h 03h 3582h RO C0F0
PCI Command Register PCICMD2 04h 05h 0000h RO,R/W U1F1
PCI Status Register PCISTS2 06h 07h 0090h RO U1F1
Revision Identification RID2 08h 08h 01h RO C0F0
Class Code CC 09h 0Bh 030000h RO U1F1
Cache Line Size Register CLS 0Ch 0Ch 00h RO C0F0
Master Latency Timer MLT2 0Dh 0Dh 00h RO C0F0
Header Type HDR2 0Eh 0Eh 00h RO C0F0
Graphics Memory Range
Address
GMADR 10h 13h 00000008h R/W,RO U1F1
Memory Mapped Range
Address
MMADR 14h 17h 00000000h R/W,RO U1F1
IO Range Register IOBAR 18h 1Bh 00000001h R/W,RO
Subsystem Vendor ID SVID2 2Ch 2Dh 0000h R/WO C0F0
Subsystem ID SID2 2Eh 2Fh 0000h R/ WO C0F0
Video Bios ROM Base
Address
ROMADR 30h 33h 00000000h RO C0F0
Interrupt Line Register INTRLINE 3Ch 3Ch 00h R/W, RO in F
#1
Interrupt Pin Register INTRPIN 3Dh 3Dh 01h RO, Reserved
In F#1
Minimum Grant Register MINGNT 3Eh 3Eh 00h RO C0F0
Maximum Latency
Register
MAXLAT 3Fh 3Fh 00h RO C0F0
Mirror of GMCH Misc
Control
MGMiscC 50h 51h --- RO CODO
FO GMCH
Misc Control
Register
Power Management
Capabilities
PMCAP D2h D3h 0221h RO COFO
Power Management
Control
PMCS D4h D5h 0000h R/W,RO U1F1
Register Description
R
102 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.11.1. VID2 – Vendor Identification Register – Device #2
Address Offset: 00h 01h
Default Value: 8086h
Access Attributes: Read Only
Size: 16 bits
The VID Register contains the vendor identification number. This 16-bit register combined with the
Device Identification Register un iquely identifies any PCI device. Writes to this register have no effect.
Bit Description
15:0 Vendor Identification Number: This is a 16-bit value assigned to Intel.
3.11.2. DID2 – Device Identification Register - Device #2
Address Offset: 02h 03h
Default Value: 3582h
Access Attributes: Read Only
Size: 16 bits
This 16-bit register combined with the Vendor Identification register uniquely identifies any PCI device.
Writes to this register have no effect.
Bit Description
15:0 Device Identification Number: This is a 16-bit value assigned to the Intel 852GM/852GMV GMCH IGD.
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 103
3.11.3. PCICMD2 – PCI Command Register - Device #2
Address Offset: 04h 05h
Default: 0000h
Access: Read Only, Read/Write
Size: 16 bits
This 16-bit register provides basic control over the IGD’s ability to respond to PCI cycles. The PCICMD
Register in the IGD disables the IGD PCI compliant master accesses to main System Memory.
Bit Description
15:10 Reserved
9 Fast Back-to-Back (FB2B) RO.
8 SERR# Enable (SERRE) RO.
7 Address/Data Stepping RO.
6 Parity Error Enable (PERRE) RO.
5 Video Palette Snooping (VPS) RO.
4 Memory Write and Invalidate Enable (MWIE) RO.
3 Special Cycle Enable (SCE) RO.
2 Bus Master Enable (BME) R/W: This bit determines if the IGD is to function as a PCI compliant master.
0= Disable IGD bus mastering (default).
1 = Enable IGD bus mastering.
1 Memory Access Enable (MAE) R/W: This bit controls the IGD’s response to System Memory space
accesses.
0= Disable (default).
1 = Enable.
0 I/O Access Enable (IOAE) R/W: This bit controls the IGD’s response to I/O space accesses.
0 = Disable (default).
1 = Enable.
Register Description
R
104 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.11.4. PCISTS2 – PCI Status Register - Device #2
Address Offset: 06h 07h
Default Value: 0090h
Access: Read Only
Size: 16 bits
PCISTS is a 16-bit status register that reports the occurrence of a PCI compliant master abort and PCI
compliant target abort. PCISTS also indicates the DEVSEL# timing that has been set by the IGD.
Bit Description
15 Detected Parity Error (DPE): Since the IGD does not detect parity, this bit is always set to 0.
14 Signaled System Error (SSE) – RO
13 Received Master Abort Status (RMAS) – RO
12 Received Target Abort Status (RTAS) – RO
11 Signaled Target Abort Status (STAS) – RO
10:9 DEVSEL# Timing (DEVT) – RO
8 Data Parity Detected (DPD) – RO
7 Fast Back-to-Back (FB2B) – RO
6 User Defined Format (UDF) – RO
5 66-MHz PCI Capable (66C) – RO
4 CAP LIST: This bit is set to 1 to indicate that the register at 34h provides an offset into the function’s PCI
Configuration Space containing a pointer to the location of the first item in the list.
3:0 Reser ved
3.11.5. RID2 – Revision Identification Register - Device #2
Address Offset: 08h
Default Value: 01h
Access: Read Only
Size: 8 bits
This register contains the revision number of the IGD. These bits are read only and writes to this register
have no effect.
Bit Description
7:0 Revision Identification Number: This is an 8-bit value that indicates the revision identification number for the
Intel 852GM/852GMV GMCH.
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 105
3.11.6. CC – Class Code Register - Device #2
Address Offset: 09h 0Bh
Default Value: 030000h
Access: Read Only
Size: 24 bits
This register contains the device programming interface information related to the Sub-Class Code and
Base Class Code definition for the IGD. This register also contains the Base Class Code and the function
sub-class in relation to the Base Class Code.
Bit Description
23:16 Base Class Code (BASEC): 03=Display controller
15:8 Sub-Class Code (SCC):
Function 0: 00h=VGA compatible or 80h=Non VGA
Function 1: 80h=Non VGA
7:0 Programming Interface (PI): 00h=Hardwired as a Display controller.
3.11.7. CLS – Cache Line Size Register - Device #2
Address Offset: 0Ch
Default Value: 00h
Access: Read only
Size: 8 bits
The IGD does not support this register as a PCI slave.
Bit Description
7:0 Cache Line Size (CLS) – RO
3.11.8. MLT2 – Master Latency Timer Register - Device #2
Address Offset: 0Dh
Default Value: 00h
Access: Read Only
Size: 8 bits
The IGD does not support the programmability of the master latency timer because it does not perform
bursts.
Bit Description
7:0 Master Latency Timer Count Val ue – RO
Register Description
R
106 Intel
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852GM/852GMV Chipset GMCH Data sheet
3.11.9. HDR2 – Header Type Register - Device #2
Address Offset: 0Eh
Default Value: 00h
Access: Read Only
Size: 8 bits
This register contains the Header Type of the IGD.
Bit Description
7 Multi Function Status (MFunc): Indicates if the device is a Multi-Function Device.
6:0 Header Code (H): This is a 7-bit value that indicates the Header Code for the IGD. This code has the value
00h, indicating a type 0 configuration space format.
3.11.10. GMADR – Graphics Memory Range Address Register - Device
#2
Address Offset: 10 13h
Default Value: 00000008h
Access: Read/Write, Read Only
Size: 32 bits
IGD graphics System Memory base address is specified in this register.
Bit Description
31:27 Memory Base Address R/W: Set by the OS, these bits correspond to address signals [31:26].
26 128-MB Address Mask – RO: 0 indicates 128-MB address
25:4 Address Mask RO: Indicates (at least) a 32-MB address range.
3 Prefetchable Memory RO: Enable prefetching.
2:1 Memor y Type RO: Indicate 32-bit address.
0 Memory/IO Space RO: Indicate System Memory space.
Register Description
R
Intel
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852GM/852GMV Chipset GMCH Datasheet 107
3.11.11. MMADR – Memory Mapped Range Address Register - Device
#2
Address Offset: 14 17h
Default Value: 00000000h
Access: Read/Write, Read Only
Size: 32 bits
This register requests allocation for the IGD registers and instructio n ports. The allocation is for 512-kB
and the base address is defined by bits [31:19].
Bit Description
31:19 Memory Base Address R/W: Set by the OS, these bits correspond to address signals [31:19].
18:4 Address Mask RO: Indicate 512 -kB address range.
3 Prefetchable Memory RO: Prevents prefetching.
2:1 Memor y Type RO: Indicates 32-bit address.
0 Memory / IO Space RO: Indicates System Memory space.
3.11.12. IOBAR – I/O Base Address Register - (Device #2)
Address offset: 18-1Bh
Default: 00000001h
Access: Read/Write
Size: 16-bits
This register provides the Base offset of the I/O registers wi thin De vice #2. Bits 15:3 are programmable
allowing the I/O Base to be located anywhere in 16-b it I/O Address Space. Bits 2:1 are fixed and return
zero, bit 0 is hardwired to a one indicating that 8-bytes of I/O space are decoded.
Access to the 8Bs of IO space is allowed in PM state D0 when IO Enable (PCICMD bit 0) set. Access is
disallowed in PM states D1-D3 or if IO Enable is clear or if Device #2 is turned off or if internal
graphics is disabled. Note that access to this IO BAR is independent of VGA functionality within Device
#2. Also note that this mechanism is available only through Function #0 of Device#2 and is not
duplicated in Function #1.
If accesses to this IO bar are allowed, then the Intel 852GM/852GMV GMCH claims all 8-bit, 16-bit, or
32-bit IO cycles from the CPU that falls within the 8B claimed.
Bit Description
31:16 Reserved
15:3 IO Base Address R/W: Set by the OS, these bits correspond to address signals [15:3].
2:1 Memor y Type RO: Indicates 32-bit address.
0 Memory / IO Space RO
Register Description
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3.11.13. SVID2 – Subsys tem Vendor Identification Register - Device #2
Address Offset: 2C 2Dh
Default Value: 0000h
Access: Read/Write Once
Size: 16 bits
Bit Description
15:0 Subsystem Vendor ID: This value is used to identify the vendor of the subsystem. This register should be
programmed by BIOS during boot-up. Once written, this register becomes Read_Only. This register can
only be cleared by a Reset.
3.11.14. SID2 – Subsystem Identification Register - Device #2
Address Offset: 2E 2Fh
Default Value: 0000h
Access: Read/Write Once
Size: 16 bits
Bit Description
15:0 Subsystem Identification: This value is used to identify a particular subsystem. This field should be
programmed by BIOS during boot-up. Once written, this register becomes Read_Only. This register can
only be cleared by a Reset.
3.11.15. ROMADR – Video BIOS ROM Base Address Registers - Device
#2
Address Offset: 30 33h
Default Value: 00000000h
Access: Read Only
Size: 32 bits
The IGD does not use a separate BIOS ROM, therefore this register is hardwired to 0’s.
Bit Description
31:18 ROM Base Address RO
17:11 Address Mask RO: Indicates 256 kB address range.
10:1 Reser ved
0 ROM BIOS Enable RO: Indicates ROM not accessible.
Register Description
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3.11.16. INTRLINE Interrupt Line Register - Device #2
Address Offset: 3Ch
Default Value: 00h
Access: Read/Write
Size: 8 bits
Bit Description
7:0 Interrupt Connection: Used to communicate interrupt line routing information. POST software writes the
routing information into this register as it initializes and configures the system. The value in this register
indicates which input of the system interrupt controller that the device’s interrupt pin is connected to.
3.11.17. INTRPIN Interrupt Pin Register - Device #2
Address Offset: 3Dh
Default Value: 01h, 00h for Function #1
Access: Read Only
Size: 8 bits
Bit Description
7:0 Interrupt Pin: As a single function device, the IGD (Integrated GFX Device) specifies INTA# as its interrupt
pin. 01h=INTA#. For Function #1, this register is set to 00h.
3.11.18. MINGNT – Minimum Grant Register - Device #2
Address Offset: 3Eh
Default Value: 00h
Access: Read Only
Size: 8 bits
Bit Description
7:0 Minimum Grant Value: The IGD does not burst as a PCI compliant master.
3.11.19. MAXLAT – Maximum Latency Register - Device #2
Address Offset: 3Fh
Default Value: 00h
Access: Read Only
Size: 8 bits
Bit Description
7:0 Maximum Latency Value: Bits[7:0]=00h. The IGD has no specific requirements for how often it needs to
access the PCI bus.
Register Description
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3.11.20. PMCAP – Power Management Capabilities Register - Device #2
Address Offset: D2h D3h
Default Value: 0221h
Access: Read Only
Size: 16 bits
Bit Description
15:11 PME Support: This field indicates the power states in which the IGD may assert PME#. Hardwired to 0 to
indicate that the IGD does not assert the PME# signal.
10:6 Reserved
5 Device Specific Initialization (DSI): Hardwired to 1 to indicate that special initialization of the IGD is required
before generic class device driver is to use it.
4 Auxiliary Power Source: Hardwired to 0.
3 PME Clock: Hardwired to 0 to indicate IGD does not support PME# generation.
2:0 Version: Hardwired to 001b to indicate there are 4 bytes of power management registers implemented.
3.11.21. PMCS – Power Management Control/Status Register - Device
#2
Address Offset: D4h D5h
Default Value: 0000h
Access: Read/Write, Read Only
Size: 16 bits
Bit Description
15 PME_Status RO: This bit is 0 to indicate that IGD does not support PME# generation from D3
(cold).
14:9 Reserved
8 PME_En RO: This bit is 0 to indicate that PME# assertion from D3 (cold) is disabled.
7:2 Reserved
1:0 PowerState R/W: This field indicates the current power state of the IGD and can be used to set the
IGD into a new power state. If software attempts to write an unsupported state to this field, write
operation must complete normally on the bus, but the data is discarded and no state change occurs.
On a transition from D3 to D0 the graphics controller is optionally reset to initial values.
Bits[1:0] Power State
00 D0 Default
01 D1
10 D2 Not Supported
11 D3
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4. Intel 852GM/852GMV GMCH System
Address Map
A system based on the GMCH supports 4 GB of addressable System Memory space and 64 kB+3B of
addressable I/O space. The I/O and System Memory spaces are divided by system configuration
software into regions. The System Memory ranges are useful either as System Memory or as specialized
System Memory, while the I/O regions are used solely to control the operation of devices in the system.
When the GMCH receives a write request whose address targets an invalid space, the data is ignored.
For reads, the GMCH responds by returning all zeros on the requesting interface.
4.1. System Memory Address Ranges
The GMCH provides a maximum System Memory of 1-GB. The GMCH does not remap APIC memory
space and does not limit DDR SDRAM space in hardware. It is the BIOS or system designer’s
responsibility to limit System Memory population so that adequate PCI High BIOS and APIC
memory space can be allocated. Figure 4 and Figure 5 represent System Memory address map in a
simplified form and provide details on mapping specific System Memory regions as defined and
supported by the GMCH.
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Figure 4. Simplified View of System Address Map
Independently
Programmable
Non-Overlapping
Memory Windows
Main
Memory
Address
Range
P C I
Memory
Address
Range
4 GB
Top of the
Main Memory
0
Graphic
(
Local)
Memory
GMCH System Memory Space
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Figure 5. Detailed View of System Address Map
Low er BI OS
Area (64 kB)
16 kB x 41
Upper
BIOS Area
(64 kB)
Expansion
Card
BIOS and
Buffer Area
(128 kB)
16 kBx8
Standard
PCI/ISA
Video
Memory
(SMM
Memory)
128 kB
DOS Area
Extended P6
Memory
PCI Memory
Range
Optional ISA
Hole
DOS
Compatibility
Memory
SYSMAP. DS4
64 G
4 G max
TOM
1 G
16 M
15 M
1 M
640 k
0 M
DOS
Compatibility
Memory
0FFFFFh
0F0000h
0EFFFFh
0DFFFFh
0C0000h
0BFFFFh
0A0000h
09FFFFh
000000h
1 MB
960 kB
896 kB
768 kB
640 kB
4.2. Compatibility Area
This area is divided into the following address regions:
0 - 640 kB DOS Area
640 – 768 kB Video Buffer Area
768 - 896 kB in 16-kB sections (total of 8 sections) - Expansion Area
896 –960 kB in 16-kB sections (total of 4 sections) - Extended System BIOS Area
960 kB - 1 MB System Memory (BIOS Area) - System BIOS Area
There are 16 System Memory segments in the compatibility area. Thirteen of the System Memory
ranges can be enabled or disabled independently for both read and write cycles.
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Table 23. System Memory Segments and Their Attributes
System Memory
Segments Attributes Comments
000000H - 09FFFFH Fixed - always mapped to main
DDR SDRAM
0 to 640 kB – DOS Region
0A0000H - 0BFFFFH Mapped to Hub Interface or IGD -
configurable as SMM space
Video Buffer (physical DDR SDRAM
configurable as SMM space)
0C0000H - 0C3FFFH WE RE Add-on BIOS
0C4000H - 0C7FFFH WE RE Add-on BIOS
0C8000H - 0CBFFFH WE RE Add-on BIOS
0CC000H - 0CFFFFH WE RE Add-on BIOS
0D0000H - 0D3FFFH WE RE Add-on BIOS
0D4000H - 0D7FFFH WE RE Add-on BIOS
0D8000H - 0DBFFFH WE RE Add-on BIOS
0DC000H - 0DFFFFH WE RE Add-on BIOS
0E0000H - 0E3FFFH WE RE BIOS Extension
0E4000H - 0E7FFFH WE RE BIOS Extension
0E8000H - 0EBFFFH WE RE BIOS Extension
0EC000H - 0EFFFFH WE RE BIOS Extension
0F0000H - 0FFFFFH WE RE BIOS Area
DOS Area (00000h-9FFFFh)
The DOS area is 640-kB in size and is always mapped to the main System Memory controlled by the
GMCH.
Legacy VGA Ranges (A0000h-BFFFFh)
The legacy 128-kB VGA memory range A0000h-BFFFFh (Frame Buffer) can be mapped to IGD
(Device #2) and to the Hub Interface depending on the programming of the VGA steering bits. Priority
for VGA mapping is constant in that the GMCH always decodes intern ally mapped devices first. Internal
to the GMCH, decode precedence is always given to IGD. The GMCH alwa ys positively decodes
internally mapped devices, namely the IGD. Subsequent decoding of regions mapped to the Hub
Interface depends on the Legacy VGA config urations bits (VGA Enable and MDAP). This region is
also the default for SMM space.
Compatible SMRAM Address Range (A0000h-BFFFFh)
When compatible SMM space is enabled, SMM-mode CPU accesses to this range are routed to physical
DDR SDRAM at this address. Non-SMM-mode CPU accesses to this range are considered to be to the
video buffer area as described above. Hub Interface originated cycles to enabled SMM space are not
allowed and are considered to be to the video buffer area.
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Monochrome Adapter (MDA) Range (B0000h - B7FFFh)
Legacy support requires the ability to have a second graphics controller (monochrome) in the system.
Accesses in the standard VGA range ar e forwarded to IGD and the Hub Interface (depending on
configuration bits). Since the monochrome adapter may be mapped to anyone of these devices, the
GMCH must decode cycles in the MDA range and forward them either to IGD or to Hub Interface. This
capability is controlled by a VGA steering bits and th e legacy configuration bit (MDAP bit). In addition
to the System Memory range B0000h to B7FFFh, the GMCH decodes IO cycles at 3B4h, 3B5h, 3B8h,
3B9h, 3BAh, and 3BFh and forwards them to the either the IGD or the Hub Interface.
Expansion Area (C0000h-DFFFFh)
This 128-kByte ISA Expansion region is divided into eight 16-kByte segments. Each segment can be
assigned one of four Read/Write states: read-only, write-only, read/write, or disabled. Typically, these
blocks are mapped through GMCH and ar e subtractively decoded to ISA space. System Memory that is
disabled is not remapped.
Extended System BIOS Area (E0000h-EFFFFh)
This 64-kByte area is divided into four 16-kByte segments. Each segment can be assigned independent
read and write attributes so it can be mapped either to main DDR SDRAM or to Hub Interface.
Typically, this area is used for RAM or ROM. System Memory segments that are disabled are not
remapped elsewhere.
System BIOS Area (F0000h-FFFFFh)
This area is a single 64-kByte segment. This segment can be assigned read and write attributes. It is by
default (after reset) Read/Write disabled and cycles are forwarded to Hub Interface. By manipulating the
Read/Write attributes, the GMCH can “shadow” BIOS into the main DDR SDRAM. When disabled,
this segment is not remapped.
4.3. Extended System Memory Area
This System Memory area covers 100000h (1 MB) to FFFFFFFFh (4 GB-1) address range and it is
divided into the following regions:
Main System Memory from 1 MByte to the Top of System Memory; maximum 512 MB.
PCI Memory space from the Top of System Memory to 4 GB with two specific ranges.
APIC Configuration Space from FEC0_0000h (4 GB-20 MB) to FECF_FFFFh and FEE0_0000h
to FEEF_FFFFh
High BIOS area from 4 GByte to 4 GByte - 2 MB
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4.4. Main System Memory Address Range (0010_0000h to
Top of Main Memory)
The address range from 1 MB to the top of main system memory is mapped to main DDR SDRAM
address range controlled by the GMCH. The Top of Memory (TOM) is limited to 512-MB DDR
SDRAM. The GMCH will forward all accesses to addresses within this range to the DDR SDRAM
unless a hole in this range is created using the fixed hole as controlled by the FDHC register. Accesses
within this hole are forwarded to Hub interface.
The GMCH provides a maximum DDR SDRAM address decode space of 4 GB. The GMCH does not
remap APIC memory space. The GMCH does not limit DDR SDRAM address space in hardware.
4.4.1. 15 MB-16 MB Window
A hole can be created at 15 MB-16 MB as controlled by the fixed hole enable (FDHC register) in Device
0 space. Accesses within this hole are forwarded to the Hub Interface. The range of physical DDR
SDRAM disabled by opening the hole is not remapped to the Top of the memory – that physical DDR
SDRAM space is not accessible. This 15 MB-16 MB hole is an optionally enabled ISA hole. Video
accelerators originally used this hole. Validation and customer SV teams also use it for some of their
test cards. That is why it is being supported. There is no inherent BIOS request for the 15-16 hole.
4.4.2. Pre-allocated System Memory
Voids of physical addresses that are not accessible as general System Memory and reside within System
Memory address range (< TOM) are created for SMM-mode and legacy VGA graphics compatibility. It
is the responsibility of BIOS to properly initialize these regions. The number of UMA optio ns has
been extended. Allocation is at a fixed address in terms of rigid positioning of UMA System Memory
ÆTOM-TSEG-UMA(size), but it is mapped at an y available address by a PCI allocation algorithm.
GMADR and MMADR are requested through BARs.
The following table details the location and attributes of the regions.
Table 24. Pre-allocated System Memory
System Memory Segments Attributes Comments
00000000H - 03E7FFFFH R/W Available System Memory 62.5 MB
03E80000H - 03F7FFFFH R/W Pre-allocated Graphics VGA memory.
1-MB (or 4/8/16/32- MB) when IGD is enabled.
03F80000H - 03FFFFFFH SMM Mode Only - CPU Reads TSEG Address Range
03F80000H - 03FFFFFFH SMM Mode Only - CPU Reads TSEG Pre-allocated System Memory
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4.4.2.1. Extended SMRAM Address Range (HSEG and TSEG)
The HSEG and TSEG SMM transaction address spaces reside in this extended System Memory area.
4.4.2.2. HSEG
SMM mode CPU accesses to enabled HSEG are remapped to 000A0000h-000BFFFFh. Non-SMM
mode CPU accesses to enabled HSEG are considered invalid are terminated immediately on the FSB.
The exceptions to this rule are Non-SMM mode Write Back cycles that are remapped to SMM space to
maintain cache coherency. Hub Interface originated cycles to enabled SMM space are not allowed.
Physical DDR SDRAM behind the HSEG transaction address is not remapped and is not accessible.
4.4.2.3. TSEG
TSEG is 1-MB in size and is at the top of physical System Memory. SMM mode CPU accesses to
enabled TSEG access the physical DDR SDRAM at the same address. Non-SMM mode CPU accesses
to enabled TSEG are considered invalid and are terminated immediately on the FSB. The exceptions to
this rule are Non-SMM-mode Write Back cycles that are directed to the physical SMM space to maintain
cache coherency. Hub Interface originated cycles that enable SMM space are not allowed.
The size of the SMRAM space is determined by the USMM value in the SMRAM register. When the
extended SMRAM space is enabled, non-SMM CPU accesses and all other accesses in this range are
forwarded to the Hub Interface. When SMM is enabled the amount of System Memory available to the
system is equal to the amount of physical DDR SDRAM minus the value in the TSEG register.
4.4.2.4. Intel Dynamic Video Memory Technology (DVMT)
The IGD supports DVMT in a non-grap hics System Memory configuration. DVMT is a mechanism that
manages System Memory and the internal graphics device for optimal graphics performance. DVMT-
enabled software drivers, working with the memory arbiter and the operating system, utilize the System
Memory to support 2D graphics and 3D applications. DVMT dynamically responds to application
requirements by allocating the proper amount of display and texturing memory.
4.4.2.5. PCI Memory Address Range (Top of Main System Memory to 4 GB)
The address range from the top of main DDR SDRAM to 4-GB (top of physical System Memory space
supported by the GMCH) is normally mapped via the Hub Interface to PCI.
As an internal graphics config uration, there are two exceptions to this rule.
1. The first ex ception is addresses decoded to the Graphics Memory Range. One per function in
device #2.
2. The second exception is addresses decoded to the System Memory Mapped Range of the Internal
Graphics Device. One per function in device #2. Both exception cases are forwarded to the
Internal Graphics Device.
There are two sub-ranges within the PCI Memory address range defined as APIC Configuration Space
and High BIOS Address Range. As an Internal Graphics Device, the Graphics Memory Range and the
Memory Mapped Range of the Internal Graphics Device MUST NOT overlap with these two ranges.
These ranges are described in detail in the following paragraphs.
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4.4.2.6. APIC Configuration Space (FEC0_0000h -FECF_FFFFh, FEE0_0000h-
FEEF_FFFFh)
This range is reserved for APIC configuration space that includes the default I/O APIC configuration
space. The default Local APIC configuration space is FEE0_0000h to FEEF_0FFFh.
CPU accesses to the Local APIC configuration space do not result in external bus activity since the
Local APIC configuration sp ace is internal to the CPU. However, an MTRR must be programmed to
make the Local APIC range uncacheable (UC). The Local APIC base address in each CPU should be
relocated to the FEC0_0000h (4 GB-20 MB) to FECF_FFFFh range so that one MTRR can be
programmed to 64-kB for the Local and I/O APICs. The I/O APIC(s) usually resides in the ICH4-M
portion of the chip-set or as a stand-alone component(s).
I/O APIC units will be located beginning at the default address FEC0_0000h. Th e first I/O APIC w ill be
located at FEC0_0000h. Each I/O APIC unit is located at FEC0_x000h where x is I/O APIC unit number
0 through F(hex). This ad dress range will be normally mapped to Hub Interface.
The address range betw een the A PIC configuration space and the High BIOS (FED0_0000h to
FFDF_FFFFh) is always mapped to the Hub Interface.
4.4.2.7. High BIOS Area (FFE0_0000h -FFFF_FFFFh)
The top 2-MB of the Extended Memory Region is reserved for System BIOS (High BIOS), extended
BIOS for PCI devices, and the A20 alias of the system BIOS. CPU begins execution from the High
BIOS after reset. This region is ma pped to Hub Interface so that the upper subset of this region aliases to
16 MB to 256-kB range. The actual address space required for the BIOS is less than 2 MB but the
minimum CPU MTRR range for this region is 2-MB so that full 2-MB must be considered.
4.4.3. System Management Mode (SMM) Memory Range
The GMCH supports the use of main System Memory as System Management RAM (SMM RAM)
enabling the use of System Management Mode. The GMCH supports three SMM options: Compatible
SMRAM (C_SMRAM), High Segment (HSEG), and Top of Memory Segment (TSEG). System
Management RAM space provides a System Memory area that is available for the SMI handler’s and
code and data storage. This System Memory resource is normally hidden from the system OS so that the
processor has immediate access to this System Memory space upon entry to SMM. The GMCH provides
three SMRAM options:
Below 1 -MByte option that supports compatible SMI handlers.
Above 1 -MByte option that allows new SMI handlers to execute with write-back cacheable SMRAM.
Above 1-MByte solu tions require changes to compatible SMRAM handlers code to properly execute
above 1-MByte.
Note: Hub Interface is not allowed to access the SMM space.
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4.4.3.1. SMM Space Restrictions
If any of the following conditions are violated the results of SMM accesses are unpredictable and may
cause the system to hang:
1. The Compatible SMM space must not be set-up as cacheable.
2. High or TSEG SMM transaction address space must not overlap address space assigned to DDR
SDRAM or to any “PCI” devices (including Hub Interface and graphics devices). This is a BIOS
responsibility.
3. Both D_OPEN and D_CLOSE must not be set to 1 at the same time.
4. When TSEG SMM space is enabled, th e TSEG space must not be reported to the OS as available
. This is a BIOS responsibility.
4.4.3.2. SMM Space Definition
SMM space is defined by its addressed SMM space and its DDR SDRAM SMM space. The addressed
SMM space is defined as the range of bus addresses used by the CPU to access SMM space. DDR
SDRAM SMM space is defined as the range of physical DDR SDRAM locations containing the SMM
code. SMM space can be accessed at one of three transaction address ranges: Compatible, High, and
TSEG. The Compatible and TSEG SMM space is not remapped and therefore the addressed and DDR
SDRAM SMM space is the same address range. Since the High SMM space is remapped the addressed
and DDR SDRAM SMM space is a different address range. Note that the High DDR SDRAM space is
the same as the Compatible Transaction Address space. The table below describes three unique address
ranges:
1. Compatible Transaction Address (Adr C)
2. High Transaction Address (Adr H)
3. TSEG Transaction Address (Adr T)
These abbreviations are used later in Table 25.
Table 25. SMM Space Transaction Handling
SMM Space Enabled Transaction Address Space (Adr) DRAM Space (DRAM)
Compatible (C) A0000h to BFFFFh A0000h to BFFFFh
High (H) 0FEDA0000h to 0FEDBFFFFh A0000h to BFFFFh
TSEG (T) (TOM-TSEG_SZ) to TOM (TOM-TSEG_SZ) to TOM
4.4.4. System Memor y Shadowing
Any block of System Memory that can be designated as read-only or write-only can be “shadowed” into
GMCH DDR SDRAM. Typically this is done to allo w ROM code to execute more rapidly out of main
DDR SDRAM. ROM is used as a read-only during the copy process while DDR SDRAM at the same
time is designated write-only. After copying, the DDR SDRAM is designated read-only so that ROM is
shadowed. CPU bus transactions are routed accordingly.
4.4.5. I/O Address Space
The GMCH does not support the existence of any other I/O devices beside itself on the CPU bus. The
GMCH generates Hub Interface or PCI bus cycles for all CPU I/O accesses that it does not claim. Within
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the host bridge the GMCH contains two internal registers in the CPU I/O space, Config uration Address
Register (CONFIG_ADDRESS) and the Configuration Data Register (CONFIG_DATA). These
locations are used to implement configuration space access mechanism and as described in the
Configuration register section.
The CPU allows 64kB +3B to be addressed within the I/O space. The GMCH propagates the CPU I/O
address without any translation on to the destination bus and therefore provides addressability for 64 k+3
byte locations. Note that the upper 3 locations can be accessed only during I/O address wrap-around
when CPU bus A16# address signal is asserted. A16# is asserted on the CPU bus whenever an I/O
access is made to 4 bytes from address 0FFFDh, 0FFFEh, or 0FFFFh. A16# is also asserted when an I/O
access is made to 2 bytes from address 0FFFFh.
A set of I/O accesses (other than ones used for configuration space access) is consumed by the internal
graphics device if it is enabled. The mechanisms for internal graphics IO decode and the associated
control is explained later.
The I/O accesses (other than ones used for configuration space access) are forwarded normally to the
Hub Interface . The GMCH wi l l not po st I/O write cycles to IDE.
4.4.6. GMCH Decode Rules and Cross-Bridge Address Mapping
The address map described above applies globally to accesses arriving on any of the three interfaces i.e.
Host bus, IGD, and Hub Interface.
4.4.7. Hub Interface Decode Rules
The GMCH accepts accesses from Hub Interface to the following address ranges:
All memory read and write accesses to Main DDR SDRAM including PAM region (ex cept SMM
space)
All memory read/write accesses to the Graphics Aperture (DRAM) defined by APBASE and
APSIZE.
Memory writes to VGA range.
All memory reads from the Hub Interface A that are targeted > 4-GB System Memory range will be
terminated with Master Abort completion, and all memory writes (>4-GB) from the Hub Interface will
be ignored.
Hub Interface System Memory accesses that fall elsewhere within the System Memory range are
considered invalid and will be remapp e d to System Memory address 0h, snooped on the ho s t bus, and
dispatched to DDR SDRAM. Reads will return all 1’s with Master Abort completion. Writes will have
BE’s deasserted and will terminate with Master Abort if completion is required. I/O cycles will not be
accepted. They are terminated with Master Abort completion packets.
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4.4.7.1. Hub Interface Accesses to GMCH that Cross Device Boundaries
Hublink accesses are limited to 256-bytes but have no restrictions on crossing address boundaries. A
single Hublink request may therefore span device boundaries (DDR SDRAM) or cross from valid
addresses to invalid addresses (or vise versa). The GMCH does not support transactions that cross device
boundaries. For reads and for writes requiring completion, the GMCH will provide separate completion
status for each naturally aligned 32 -or 64 -byte block. If the starting address of a transaction hits a valid
address, the portion of a request that hits that target dev ice (DDR SDRAM) will complete normally. The
remaining portion of the access that crosses a device boundary (targets a different device than that of the
starting address) or hits an invalid address will be remapped to System Memory address 0h, snooped on
the host bus, and dispatched to DDR SDRAM. Reads will return all 1’s with Master Abort completio n.
Writes will have BE’s deasserted and will terminate with Master Abort if completion is required.
If the starting address of a transaction hits an invalid address the entire transaction will be remapped to
System Memory address 0h, snooped on the host bus, and dispatched to DD R SDRAM. Reads will
return all 1’s with Master Abort completio n. Writes will have BE’s deasserted and will terminate with
Master Abort if completion is required.
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5. Functional Description
5.1. Host Interface Overview
The GMCH Processor System Bus uses source synchronous transfer for the address and data signals.
The address signals are double pumped and two addresses can be generated ev ery bus clock. At 100-
MHz bus frequency, the two address signals run at 200-MT/s for a maximum address queue rate of 50-
M addresses/sec. The data is quad pumped and an entire 64B cache line can be transferred in two bus
clocks. At 100-MHz bus frequency, the data signals run at 400 MHz for a maximum bandwidth of 3.2-
GB/s. The 852GM/852GMV GMCH has In-Order Queue to support outstanding pipelined address
requests on the host bus.
5.2. Dynamic Bus Inversion
The GMCH supports Dynamic Bus Inversion (DBI) when driving and receiving data from the Host Bus.
DBI limits the number of data signals that are driven to a low voltage on each quad pumped data phase.
This decreases the power consumption of the GMCH. DINV[3:0] indicates if the corresponding 16 bits
of data are inverted on the bus for each quad pumped data phase:
Table 26. Relation of DBI Bits to Data Bits
DINV[3:0] Data Bits
DINV[0]# HD[15:0]#
DINV[1]# HD[31:16]#
DINV[2]# HD[47:32]#
DINV[3]# HD[63:48]#
Whenever the CPU or the GMCH drives data, each 16-bit segment is analyzed. If more than eight of the
16 signals would normally be dr iven low on the bus the corresponding DINV# signal will be asserted
and the data will be inverted prior to being driven on the bus. W henev er the CPU or the GMCH receives
data it monitors DINV[3:0 ]# to determine if the corresp onding data segment should be inverted.
5.2.1. System Bus Interrupt Delivery
Each processor supports System Bus interrupt delivery. It does not support the APIC serial bus interrupt
delivery mechanism. Interrupt related messages are encoded on the System Bus as “Interrupt Message
Transactions”. In a GMCH platform, System Bus interrupts may originate from the processor on the
System Bus, or from a downstream device on Hub Interface.
In a GMCH platform, the ICH4-M contains IOxAPICs and its interrupts are generated as upstream Hub
Interface Memory Writes. Furthermore, PC I 2.2 defines MSI’s (Message Signaled Interrupts) that are
also in the form of Memory Writes. A PCI 2.2 device may generate an interrupt as an MSI cycle on its
PCI bus instead of asserting a hardware signal to the IOxAPIC. The MSI may be directed to the
IOxAPIC, which in turn generates an interrupt as an upstream Hub Interface Memory Write.
Alternatively the MSI may be directed directly to the System bus. The target of an MSI is dependent on
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the address of the interrupt Memory Write. The GMCH forw ards inbound Hub Interface Memory Writes
to address 0FEEx_xxxxh, to the System bus as “Interrupt Message Transactions”.
5.2.2. Upstream Interrupt Messages
The GMCH accepts message based interrupts from its Hub Interface and forwards them to the System
bus as Interrupt Message Transactions. The interru pt messages presented to the GMCH are in the form
of Memory Writes to address 0FEEx_xxxxh. At the Hub Interface the Memory Write interrupt message
is treated like any other Memory Write; it is either posted into the inbound data buffer (if space is
available) or retried (if data buffer space is not immediately available). Once posted, the Memory Write
from the Hub Interface, to address 0FEEx_xxxxh, is decoded as a cycle that needs to be propagated by
the GMCH to the System bus as an Interrupt Message Transaction.
5.3. System Memory Interface
5.3.1. DDR SDRAM Interface Overview
The GMCH supports DDR SDRAM at 200/266-MHz and includes the following support:
Up to 1-GB of PC1600/PC2100 DDR SDRAM (Intel 852GM/852GMV GMCH)
PC1600/2100 unbuffered 200-pin DDR SDRAM SO-DIMMs
Maximum of two SO-DIMMs, single-sided and/or double-sided
The 2-bank select lines SBA[1:0] and the 13 Address lines SMA[12:0 ] allow the GMCH to support 64-
bit wide SO-DIMMs using 128-Mb, 256-Mb , and 512-Mb DDR SDRAM technology. While address
lines SMA[9:0] determine the starting address for a burst, burst lengt h can onl y be 4. Fou r chi p selects
SCS[3:0]# lines allow a maximum of two rows of single-sided DDR SDRAM SO-DIMMs and four rows
of double-sided DDR SDRAM SO-DIMMs.
The GMCH main System Memory controller targets CAS latencies of 2 an d 2.5 for DDR SDRAM. The
GMCH provides refresh functionality with a programmable rate (normal DDR SDRAM rate is 1
refresh/15.6 s). For write operations of less than a full cache line, GMCH will perform a cach e-line
read and into the write buffer and perform byte-wise write-merging in the write buffer.
5.3.2. System Memory Organization and Configuration
5.3.2.1. Configuration Mechanism for SO-DIMMs
Detection of the type of DDR SDRAM in stalled on the SO-DIMM is supported via Serial Presence
Detect mechanism as defined in the JEDEC 200-pin SO- DIMM specification.
Before any cycles to the System Memory interface can be supported, the GMCH DDR SDRAM
registers must be initialized. The GMCH must be configu red for operation with the installed System
Memory types. Detection of System Memory type and size is done via the System Management Bus
(SMB) interface on the ICH4-M. This two-w ire bus is used to extract the DDR SDRAM type and size
information from the Serial Presence Detect port on the DDR SDRAM SO-DIMMs. DDR SDRAM SO-
DIMMs contain a 5-pin Serial Presence Detect interface, including SCL (serial clock), SDA (serial data)
and SA[2:0]. Devices on the SMBus have a 7-bit address. For the DDR SDRAM SO-DIMMs, the
upper four bits are fixed at 1010. The lower three bits are strapped on the SA[2:0] pins. SCL and SDA
are connected directly to the System Management Bus on the ICH4-M. Thus data is read from the Serial
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Presence Detect port on the SO-DIMMs via a series of I/O cycles to the south bridge. The BIOS needs
to determine the size and type of System Me mory used for each of the rows of System Memory in order
to properly configure the GMCH System Memory interface.
For SMBus Configuration and Access of the Serial Presence Detect Ports, refer to the Intel 82801DBM
I/O Control ler Hub 4 Mobile (ICH4-M) Datasheet (order number: 252337) for more detail.
5.3.2.2. System Memory Register Programming
This section provides an overview of how the required information for programming the DDR SDRAM
registers is obt ai ned from the Serial Presence Detect ports on the SO-DIMMs. The Serial Presence
Detect ports are used to determine Refresh Rate, MA an d MD Buffer Strength, Row Type (on a row by
row basis), DDR SDRAM Timings, Row Sizes and Row Page Sizes. The following table lists a subset
of the data available through the on board Serial Presence Detect ROM on each SO-DIMM.
Table 27. Data Bytes on SO-DIMM Us ed for Programming DRAM Registers
Byte Function
2 System Memory Type (DDR SDRAM)
3 Number of Row Addresses, not counting Bank Addresses
4 Number of Column Addresses
5 Number of SO-DIMM banks
11 No ECC
12 Refresh Rate/Type
17 Number Banks on each Device
The above table is only a subset of the defined SP D bytes on the SO-DIMMs. These bytes collectively
provide enough data for programming the GMCH DDR SDRAM registers.
5.3.3. DDR SDRAM Performance Description
The overall System Memory performance is controlled by the DDR SDRAM timing register, pipelining
depth used in GMCH, System Memory speed grade and the type of DDR SDRAM used in the system.
Besides this, the exact performance in a system is also dependent on the total System Memory
supported, external buffering and System Memory array layout. The most important contribution to
overall performance by the System Memory controller is to minimize the latency required to initiate and
complete requests to System Memory, and to support the highest possible bandwidth (full streaming,
quick turn-arounds). One measure of performance is the total flight time to complete a cache line
request. A true discussion of performance really involves the entire chipset, not just the System Memory
controller.
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5.4. Integrated Graphics Overview
The GMCH provides a highly integrated graphics accelerator and PCI set while allowing a flexible
Integrated System Graph ics solution.
Figure 6. Intel 852GM/852GMV GMCH Graphics Block Diagram
A_gmch_bl
k
Instr./
Data Setup/Transform
3D Engine
Scan Conversion
Texture Engine
Raster Engine
2D Engine
Video Engine
(
MPEG2 Decode
)
Overlay
Sprite
Cursor
Primary
Display
Secondary
Display
Display C
2
n
d
Overlay
A
lpha
Blend/
Gamma/
CRC
Cursor
Cntl
Mux
Port
DAC
LVDS
DVOC
DDC
Memory Control
DDR/SDRAM
Pipe A
Pipe B
High bandwidth access to da ta is provided through the System Memory port. The GMCH uses a tiling
architecture to minimize page miss latencies and thus maximize effective rendering bandwidth.
5.4.1. 3D/2D Instruction Processing
The GMCH contains an extensive set of instructions that control various functions in cluding 3D
rendering, BLT operations, display, MPEG decode acceleration, and overlay. The 3D instructions set
3D pipeline states and control the processing functions. The 2D instructions provide an efficient method
for invoking BLT operations.
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5.4.2. 3D Engine
The 3D engine of the GMCH has been designed with a deeply pipelined architecture, where performance
is maximized by allowing each stage of the pipeline to simultaneously operate on d ifferent primitives or
portions of the same primitive. The GMCH supports the following :
Perspective-correct Texture Mapping,
Multitextures
Embossed and Dot-Product Bump-Mapping
Cubic Environment Maps
Bilinear, Trilinear, and Anisotrop ic MIP mappe d filtering
Gouraud shading
Alpha-blending
Per-Vertex and Per- Pixel Fog
Z/W Buffering
These features are independently controlled via a set of 3D instructions. The 3D pipelin e subsystem
performs the 3D rendering acceleration. The main blocks of the pipeline are the Setup Engine, Scan
Converter, Texture Pipeline, and Raster Pipeline. A typical programming sequence would be to send
instructions to set the state of the pipeline followed by rendering instructions con taining 3D primitive
vertex data.
5.4.2.1. Setup Engine
The GMCH 3D setup engine takes the input data associated with each vertex of a 3D primitive and
computes the various parameters required for scan conversion. In formatting this data, the GMCH
maintains sub-pixel accuracy. The per-vertex data is converted into gradients that can be used to
interpolate th e data at any pixel within a polygon (colors, alpha, Z or W depth, fog, and texture
coordinates). The pix e ls covered by a polygon are identified and per-pixel texture addresses are
calculated.
5.4.2.2. Viewport Transform and Perspective Divide
A 3D-geometry pipeline typically involves transformation of vertices from model space to clipping
space followed by clip test and clipping. Lighting can be performed during the transformation or at any
other point in the pipeline. After clipping, the next stage involves perspective divide followed by
transformation to the viewport or screen space. The GMCH can support Viewport Transform and
Perspective Divide portion of the 3D geometry pipeline in hardware.
5.4.2.3. 3D Primitives and Data Formats Support
The 3D primitives rendered by the GMCH are points, lines, discrete triangles, line strips, triangle strips,
triangle fans, and polygons. In addition to this, the GMCH supports DirectX’s* Flexible Vertex Format*
(FVF), which enables th e application to specify a variable length parameter list, obviating the need for
sending unused information to the hardware. Strips, Fans, and Indexed Vertices as well as FVF improves
delivered vertex rate to the setup engine significantly.
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5.4.2.4. Pixel Accurate Fast Scissoring and Clipping Operation
The GMCH supports clipping to a scissoring rectangle within the drawing window. The GMCH clipping
and scissoring in hardware reduce the need for software to process polygons, and thus improves
performance. During the setup stage, the GMCH clips polygons to the drawing window. The scissor
rectangle accelerates the clipping process by allowing the driver to clip to a bigger region than the
hardware renders to. The scissor rectangle is pixel accurate, and independent of line and point width.
The GMCH supports a single scissor box rectangle.
5.4.2.5. Backface Culling
As part of the setup, the GMCH can discard polygons from further processing, if they are either facing
away from or towards th e user’s viewpoint. This operation, referred to as “Back Face Culling” is
accomplished based on the “clockwise” or “counter-clockwise” orientation of the vertices on a primitive.
This can be enabled o r di sabled by the driver.
5.4.2.6. Scan Converter
The Scan Converter takes the vertex and edge information is us ed to identify all pixels that are affected
by features being rendered. It works on a per-polygon basis, and one polygon may be en tering the
pipeline while cal cul a t i ons fi n ish on another.
5.4.2.7. Texture Engine
The GMCH allows an image pattern, or video to be placed on the surface of a 3D polygon. The texture
engine performs texture color or chromakey matching texture filtering (an-isotropic, tri-linear, and
bilinear), and YUV to RGB conversion.
As texture sizes increase beyond the bounds of graphics memory, executing textures from graphics
memory becomes impractical. Every rendering pass would require copying each and every texture in a
scene from System Memory to graphics memory, then using the texture, and finally overwriting the local
memory copy of the texture by copying the next texture into graphics memory. The GMCH, using
Intel’s Direct Memory Execution model, simplifies this process by rendering each scene using the
texture located in System Memory. The GMCH includes a cache controller to avoid frequent memory
fetches of recently used texture data.
5.4.2.8. Perspective Correct Texture Support
A textured polygon is generated by mapping a 2D texture pattern onto each pixel of the polygon. A
texture map is like wa llpaper pasted onto the polygon. Since polygons are rendered in persp ective, it is
important that texture be mapped in perspective as well. Without perspective correction, texture is
distorted when an object recedes into the distance. Perspective correction involves a compute-inten sive
“per-pixel-divide” operation on each pixel. Perspective correction is necessary for realistic 3D graphics.
5.4.2.9. Texture Decompression
As the textures’ average size gets larger with higher color depth and multiple textures become the norm,
it becomes increasingly important to provide support for compressed textures.
DirectX* supports Texture Compression/Decompression to reduce the bandwidth required to deliver
textures. The GMCH supports several compressed texture formats (DirectX: DXT1, DXT2 , DXT3,
DXT4, DXT5) and OpenGL FXT1 formats.
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5.4.2.10. Texture Chromakey
Chromakey is a method for removing a specific color or range of colors from a texture map before it is
applied to an object. For “nearest” texture filter modes, removing a color simply makes tho se portions of
the object transp arent (the previous contents of the back buffer show through). For “linear “ texture
filtering modes, the texture filter is modified if only the non-nearest neighbor tex e ls match th e key
(range).
Chromakeying can be performed for both paletted and non-paletted textures, and removes texels that fall
within a specified color range. The Chromakey mode refers to testing the ARGB or YUV components
to see if they fall between high and low state variable values. If the color of a texel con tribution is in this
range and chromakey is enabled, then this contribution is removed from the resulting pixel color.
5.4.2.11. Anti-Aliasing
Aliasing is one of the artifacts th at degrade image quality. In its simplest manifestation, aliasing causes
the jagged staircase effects on sloped lines and polygon edges. Another artifact is the moiré patterns,
which occur as a result of the fact that there is very small number of pixels available on screen to contain
the data of a high-resolution texture map.
Full Scene Anti-Aliasing uses super-sampling , which means that the image is rendered internally at a
higher resolution th an it is displayed on screen. The GMCH can render internally at 1600x1 200 and then
this image is down-sampled (via a Bilinear filter) to the screen resolution of 640 x480 and 800x600. Full
Scene Anti-aliasing removes jaggies at th e edges as well as moiré patterns. The GMCH renders the
super-sampled image up to 2K x 2K pixel dimensions. The GMCH then reads it as a texture and bilinear
filters it to the final resolution.
5.4.2.12. Texture Map Filtering
Many texture-mapping modes are supported. Perspective correct mapping is always performed. As the
map is fitted across the po lygon, the map can be tiled, mirrored in either the U or V directions, or
mapped up to the end of the texture and no longer placed on the object (this is known as clamp mode).
The way a texture is combined with other object attributes is also definable.
The GMCH supports up to 12 Levels-of-Detail (LODs) ranging in size from 2048x2048 to 1x1 texels.
(A texel is defined as a texture map element.) Included in the texture processor is a texture cache, which
provides efficient MIP-mapping.
The GMCH supports 7 types of texture filtering:
Nearest (also known as Point Filtering): Texel with coordinates nearest to the desired pixel is
used. (This is used if only one LOD is present.)
Linear (also known as Bilinear Filtering): A weighted average of a 2x2 area of texels surrounding
the desired pixel is used. (This is used if only one LOD is present.)
Nearest MIP Nearest (also known as Point Filtering ): This is used if many LODs are present. The
nearest LOD is chosen and the texel with coordinates nearest to the desired pixel are used .
Linear MIP Nearest (Bilinear MIP Mapping): This is used if many LODs are present. The nearest
LOD is chosen and a weighted average of a 2x2 area of texels surrounding the desired pixel is
used (four texels). This is also referred to as Bilinear MIP Mapping.
Nearest MIP Linear (Point MIP Mapping): This is used if many LODs are present. Two
appropriate LODs are selected and within each LOD the texel with coordinates n earest to the
desired pixel are selected. The Final texture value is generated by linear interpolation between the
two texels selected from each of the MIP Maps.
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Linear MIP Linear (Trilinear MIP Mapping): This is used if many LODs are present. Two
appropriate LODs are selected and a weighted average of a 2x2 area of texels surrounding the
desired pixel in each MIP Map is generated (four texels per MIP Map). The Final texture value is
generated by linear interpolation between the two texels generated for each of the MIP Maps.
Trilinear MIP Mapping is used minimize the visibility of LOD transitions across the polygon .
Anisotropic MIP Nearest (A nisotropic Filtering): This filter can be used when textured object
pixels map back to significantly non-square regions of the texture (e.g., when the texture is scaled
in one screen direction than the other screen direction).
Both DirectX and OGL (Rev.1.1) allow s upport for all these filtering modes.
5.4.2.13. Multiple Texture Composition
The GMCH also performs multiple texture composition. This allows th e combination of two or greater
MIP maps to produce a new one with new LODs and texture attributes in a single or iterated pass. The
setup engine su pports up to four texture map coordinates in as single pass. The GMCH allows up to two
Bilinear MIP Maps or a single Trilinear MIP Map to be composited in a single pass. Greater than two
Bilinear MIP Maps or more than one Trilinear MIP Map would require multiple passes. The actual
blending or composition of the MIP Maps is done in the raster engine. The texture engine provides the
required texels including blend ing information.
Flexible vertex format support allows multi-texturing because it makes it possible to pass more than one
texture in the vertex structure.
5.4.2.14. Cubic Environment Mapping
Environment maps allow applications to render scenes with complex ligh ting and reflections while
significantly decreasing CPU load. There are several methods to generate environment maps such as
spherical, circular and cubic. The GMCH supports cubic reflection mapping over spherical and circular
since it is the best choice to provide real-time enviro nment mapping for complex lighting and reflections.
Cubic Mapping supports a texture map for each of the 6 cube faces. These can be generated by pointing
a camera with a 90-degree field-of-view in the appropriate direction. Per-vertex vectors (normal,
reflection or refraction) are interpolated across the polygon and the intersection of these vectors with th e
cube texture faces are calculated. Texel values are then read from the intersection point on the
appropriate face and filtered according ly.
5.4.2.15. Bump Mapping
The GMCH only supports embossed and dot product bump map ping, not environment bump mapping.
5.4.3. Raster Engine
The Raster Engine is where the color data such as fogging, specular RGB, texture map blending, etc. is
processed. The final color of the pixel is calculated and the RGB valu e combin ed with the
corresponding components resulting from the Texture Engine. These textured pixels are modified by the
specular and fog parameters. These specular highlighted, fogged, textured pixels are color blended with
the existing values in the frame buffer. In parallel, stencil, alpha, and depth buffer tests are conducted
which will determine whether the Frame and Depth Buffers will be updated with the new pixel values.
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5.4.3.1. Texture Map Blending
Multiple Textures can be blended toge ther in an iterative process and ap plied to a primitive. The GMCH
allows up to four distinct or shared texture coordinates and texture maps to be specified onto the same
polygon. Also, the GM CH supports a texture coordinate set to access multiple texture maps. State
variables in multiple textures are bound to texture coordinates, texture map or texture blending.
5.4.3.2. Combining Intrinsic and Specular Color Components
The GMCH allows an independently specified an d interpolated “specular RGB” attribute to be added to
the post-texture blended pixel color. This feature provides a full RGB specular highlight to be applied to
a textured surface, permitting a high quality reflective colored lighting effect n ot available in dev ices,
which apply texture after the lighting comp onents have been comb ined. If specular-add state variable is
disabled, only the resultant colors from the map blending are used. If this state variable is enabled, the
specular RGB color is added to the RGB values from the output of the map blending.
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5.4.3.3. Color Shading Modes
The Raster Engine supports the flat and Gouraud shading modes. These shading modes are programmed
by the appropriate state variables issued through the command stream.
Flat shading is performed by smoothly interpolating the vertex intrinsic color components (Red,
Green, Blue), Specular (R, G, B), Fog, and Alpha to the pixel, where each vertex color has the
same value. The setup engine substitutes one of the vertex ’s attribute values for the other two
vertices attribute values thereby creating the correct flat shading terms. This condition is set up by
the appropriate state variables issued prior to rendering the primitive.
Gouraud shading is performed by smoothly interpolating the vertex intrinsic color components
(Red, Green, Blue). Specular (RGB), Fog, and Alpha to the pixel, where each vertex color has a
different value. All the attributes can be selected independently to one of the shading mode by
setting the appropriate value state variables.
5.4.3.4. Color Dithering
Color Dithering in the GMCH helps to hide color quantization errors for 16-bit color buffers. Color
Dithering takes advantage of the human eye’s propensity to “average” the colors in a small area. Input
color, alpha, and fog components are converted from 8-bit components to 5-bit or 6-bit component by
dithering. Dithering is performed on blended textured pixels. In 32-bit mode, dithering is not performed.
5.4.3.5. Vertex and Per Pixel Fogging
Fogging is used to create atmospheric effects such as low visibility conditions in flight simulator-type
games. It adds another level of realism to computer-generated scenes. Fog can be used for depth cueing
or hiding distant objects. With fog, distant objects can be rendered with fewer details (less polygons),
thereby improving the renderin g speed or frame rate. Fog is simulated by attenuating the color of an
object with the fog color as a function of distance, and the greater the distance, the higher the density
(lower visibility for distant objects). There are two ways to implement the fogging technique: per-vertex
(linear) fogging and per-pixel (non-linear) fogging. The per-vertex method interpolates the fog value at
the vertices of a polygon to determine the fog factor at each pixel within the polygon. This method
provides realistic fogging as long as the polygons are small. With large polygons (such as a ground plane
depicting an airport runway), the per-vertex technique results in unnatural fogging.
The GMCH supports both types of fog operations, vertex and per pixel or table fog. If fog is disabled,
the incoming color intensities are passed unch anged to the destination blend unit. If fog is enabled, the
incoming pixel color is blended with the fog color based on a fog coefficient on a per pixel basis using
the following eq uation before sending to the destination blend unit.
5.4.3.6. Alpha Blending
Alpha Blending in the GMCH adds the material property of transparency or opacity to an object. Alpha
blending combines a source pixel color and alpha component with a destination pixel colo r and alpha
component. For example, this is so that a glass surface on top (source) of a red surface (destination)
would allow mu ch of the red base color to show through.
Blending allows the sou r ce and destination color values to be multiplied by programmable factors and
then combined via a programmable blend function. The combined and independent selection of factors
and blend function s for color and alpha is supported.
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5.4.3.7. Color Buffer Formats: (Destination Alpha)
The Raster Engine supports 8-bit, 16-bit, and 32-bit Color Buffer Formats. The 8-bit format is used to
support planar YUV420 format, which is used only in Motion Compensation and Arithmetic Stretch
format. The bit format of Color and Z is allowed to mix.
The GMCH can support an 8-bit destination alpha in 32-bit mode. Destination alpha is supported in 16-
bit mode in 1555 or 4444 format. The In tel 852GM/852GMV GMCH does not support general 3D
rendering to 8-bit surfaces. 8-bit destinations are supported for operations on planar YUV surfaces (e.g.,
stretch Blts) where each 8-bit color component is written in a separate pass. The GMCH also supports a
mode where both U an d V pl anar surfaces can be operated on simultaneously.
The frame buffer of th e GMCH contains at least two hardware buffers - the Front Buffer (display buffer)
and the Back Buffer (rendering buffer). While the back buffer may actually coincide with (or be part of)
the visible display surface, a separate (screen or window-sized) back buffer is typically used to permit
double-buffered drawing. That is, the image being drawn is not visible until the scene is complete and
the back buffer made visible or copied to the front buffer via a 2D BLT operation. Rendering to one
buffer and displaying from the other buffer removes image tearing artifacts. Additionally, more than
two back buffers (e.g., triple-buffering) can be supported.
5.4.3.8. Depth Buffer
The Raster Engine is able to read and write from this buffer and use the data in per fragment operations
that determine resultant color and depth value of the pixel for the fragment are to b e updated or not.
Typical applications for entertainment or visual simulations w ith exterior scenes require far/near ratios
of 1000 to 10000. At 1000, 98% of the range is spent on the first 2% of the depth. This can cause hidden
surface artifacts in distant objects, especially when using 16-bit depth buffers. A 24-bit Z-buffer provides
16 million Z-values as opposed to only 64 k with a 16-bit Z-buffer. With lower Z-resolution, two distant
overlapping objects may be assigned the same Z-value. As a result, the rendering hardware may have a
problem resolving the order of the objects, and the object in th e back may appear through the object in
the front.
By contrast, when w (or eye-relative z) is used, th e buffer bits can be more evenly allocated between the
near and far clip planes in world space. The key benefit is that the ratio of far and near is no longer an
issue, and allows applications to support a maximum range of miles, yet still get reasonably accurate
depth buffering within inches of th e eye point. The selection of depth buffer size is relatively
independent of the color buffer. A 16-bit Z/W or 24-bit Z/W buffer can be selected with a 16-bit color
buffer. Z buffer is not supported in 8-bit mode.
5.4.3.9. Stencil Buffer
The Raster Engine provides 8-bit sten cil buffer storage in 32-bit mode and the ability to perform stencil
testing. Stencil testing controls 3D drawing on a per pixel basis and conditionally eliminates a pixel on
the outcome of a comparison between a stencil reference value and the value in the stencil buffer at the
location of the source pixel being processed. They are typically used in multipass algorithms to achieve
special effects, such as decals, ou tlining, shadows, and constructive so lid geometry rendering.
One of three possible stenci l operations is performed when stencil testing is enabled. The stencil
operation specifies how the stencil buffer is modified when a fragment passes or fails the stencil test.
The selection of the stencil operation to be perfor med is based upon the result of the stencil test and the
depth test. A stencil write mask is also included that controls the writing of particular bits into the stencil
buffer. It selects between the destination value and the updated value on a per-bit basis. The mask is 8-
bit wide.
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5.4.3.10. Projective Textures
The GMCH supports two simultan eous projective textures at full rate processing. These textures require
three floating-point texture coordinates to be included in the FVF format. Projective textures enable
special effects such as projecting spot light textures obliquely onto walls, etc.
5.4.4. 2D Engine
The GMCH provides an extensive set of 2D instructions and 2D HW acceleration for block transfers of
data (BLTs). The BLT engine provides the ability to copy a source block of data to a destinatio n and
perform operations (e.g., ROP1, ROP2, and ROP3) on the data using a pattern, and/or another
destination. The Stretch BLT engine is used to move source data to a destination that need not be the
same size, with source transparency. Performing these common tasks in hardware reduces CPU load,
and thus improves performance.
5.4.4.1. 256-Bit Pattern Fill and BLT Engine
Use of this BLT engine accelerates the Graphical User Interface (GUI) of Microsoft* Windows*. The
GMCH BLT Engine provides hardware acceleration of block transfers of pixel data for many common
Windows operations. The term BLT refers to a block transfer of pixel data between System Memory
locations. The BLT engine can be used for the following:
Move rectangular blocks of data between System Memory locations
Data Alignment
Perform logical operations (raster ops)
The rectangular block of data does not change as it is transferre d bet ween System Mem ory locati ons.
Data to be transferred can consist of regions of System Memory, patterns, or solid color fills. A pattern
will always be 8x8 pixels wide and may be 8-bits, 16-bits, or 32-bits per pixel.
The GMCH BLT engine has the ability to expand monochrome data into a color depth of 8-bits, 16-bits,
or 32-bits. BLTs can be either opaque or transparent. Opaque transfers, move the data specified to the
destination. Transparent transfers compare destination color to source color and write according to th e
mode of transparency selected.
Data is horizontally and vertically aligne d at the destination. If the destination for the BLT overlaps with
the source System Memory location, the GMCH can specify which area in System Memory to begin the
BLT transfer. Hardware is included for all 256 raster operations (Source, Pattern, and D estination)
defined by Microsoft, including transparent BLT.
The GMCH has instructions to invoke BLT operations, permitting software to set up instruction buffers
and use batch processing as described in the Instruction Processi ng Secti o n. The GMCH can pe rf orm
hardware clipping during BLTs.
5.4.4.2. Alpha Stretch BLT
The stretch BLT function can stretch source data in the X and Y directions to a destination larger or
smaller than the source. Stretch BLT functionality expands a region of System Memory into a larger or
smaller region using replication and interpolation. The stretch BLT function also provides fo rmat
conversion and d a ta alignment.
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5.4.5. Planes and Engines
The GMCH display can be functionally delineated into Planes and Engines (Pipes and Ports). A plane
consists of rectangular shaped image that has characteristics such as source, size, position, method, and
format. These planes get attached to source surfaces, which are rectangular System Memory surfaces
with a similar set of characteristics. They are also associated with a particular destination pipe.
A pipe consists of a set of planes that will be combined and a timing generator. A port is the destin ation
for th e result of the pipe. Th erefore, planes are associated with pipes and pipes ar e associated with ports.
5.4.5.1. Dual Pipe Independent Display Functionality
The display consists of two display pipes, A and B. Pipes have a set of planes that are assigned to them
as sources. The analog display port may only use Pipe A or Pipe B, the DVO C port may use either Pipe
A or Pipe B, and the LFP LVDS interface may only use Pipe B. This limits the resolutions available on a
digital display w hen an analog CRT is active.
Table 28. Dual Display Usage Model (Intel 852GM/852GMV GMCH)
Display Pipe A Display Pipe B
CRT LVDS
DVO C CRT
CRT DVO C
DVO C LVDS
CRT/DVO C LVDS
5.4.6. Hardware Cursor Plane
The GMCH supports two hardw are cursors. The cursor plane is one of the simplest display planes. With
a few exceptions, has a fixed size of 64 x 64 and a fixed Z-order (top). In legacy modes, cu rsor can cause
the display data below it to be inverted. In the alpha blend mode, true color cursor data can be alpha
blended into the display stream. It can be assigned to either display pipe A or display pipe B and
dynamically flipped from one to the other when both are running.
5.4.6.1. Cursor Color Formats
Color data can be in an indexed format or a true color format. Indexed data uses the entries in the four-
entry cursor palette to convert the two-bit index to a true color fo rmat before b eing passed to the
blenders. The index can optionally specify that a cursor pixel be transparent or cause an inversion of the
pixel value below it or one of two colors from the cursor palette. Blending of YUV or RGB data is only
supported with planes that have data of the same format.
5.4.6.2. Popup Plane (Second Cursor)
The popup plane is used for control functions in mob ile applications. Only the hardware curso r has a
higher Z-order precedence over the hardware icon. In standard modes (non-VGA) either cursor A or
cursor B can be used as a Popup Icon. For VGA modes, 32-bpp data format is not supported.
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5.4.6.3. Popup Color Formats
Source color data for the popup is in an indexed fo rmat. Index ed data uses the entries in the four-entry
cursor palette to convert th e two-b it ind ex to a true co lor format before being passed to the blenders.
Blending of color data is only supported with data of the same format.
5.4.7. Overlay Plane
The overlay engine provides a method of merging either video capture data (from an external Video
Capture device) or data delivered by the CPU, with the graphics data on the screen.
5.4.7.1. Multiple Overlays (Display C)
A single overlay plane and scalar is imple mented. This overlay plane can be connected to the primary
display, secondary display or in bypass mode. In the default mode, it appears on the primary display.
The overlay may be displayed in a multi- monitor scenario for single-pipe simultaneous disp lays only.
Picture-in-Picture feature is supported via software through the arithmetic stretch blitter.
5.4.7.2. Source/Destination Color/Chromakeying
Overlay source/destinatio n chromakeying enables blending of the overlay with the underlying graphics
background. Destination co lor-/chromakeying can be used to handle occluded portions of the overlay
window on a pixel-by-pixel basis that is actually an underlay. Destination color keying supports a
specific color (8-bit or 15-bit) mode as well as 32-bit alpha blending.
Source color/chromakeying is used to handle transparency based on the overlay window on a pixel-by-
pixel basis. This is used when “blue screening” an image to overlay the image on a new background
later.
5.4.7.3. Gamma Correction
To compensate for overlay color intensity loss, the overlay engine supports independent gamma
correction. This allows the overlay data to be converted to linear data or corrected for the display device
when not blending.
5.4.7.4. YUV to RGB Conversion
The format conversion can be bypassed in th e case of RGB source data.
5.4.7.5. Color Control
Color control provides a method of changing the color characteristics of the pixel data. It is applied to
the data while in YUV format and uses input parameters such as brigh tness, saturation, hue (tint) and
contrast. This feature is supplied for the overlay on ly and works in YUV formats o nly.
5.4.7.6. Dynamic Bob and Weave
Interlaced data that originates from a video camera creates two fields that ar e temporally offset by 1/60
of a second. There are several schemes to de-interlace the video stream: line replication, vertical
filtering, field merging, and vertical temporal filterin g. Field merging takes lines from the previous field
and inserts them into the current field to construct the frame – this is know n as We aving. This is the best
solution for images with little motion; however, showing a frame that consists of the two field s will have
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serration or feathering of moving edge s when there is motion in the scene. Vertical filtering or “Bob ”
interpolates adjacent lines rather replicating the nearest neighbor. This is the best solution for images
with motion however, it will have reduced spatial resolu tion in areas that have no motion and introduce
jaggies. In absence of any other de-inter lacing, these form the baseline and are supported by the GMCH.
5.4.8. Video Functionality
The GMCH supports MPEG-2 decodin g ha rdware, sub-picture support and DTV all format decode.
5.4.8.1. MPEG-2 Decoding
The GMCH MPEG2 Decoding supports Hardware Motion Compensation (HWMC). The GMCH can
accelerate video decoding for the following video coding standards:
MPEG-2 support
MPEG-1: Full feature su pport
H.263 support
MPEG-4: Only supports some features in the simple profile.
The GMCH HWMC interface is optimized for Microsoft’s* VA API. Hardware Video Acceleration
API (HVA) is a generic DirectDraw and DirectShow interface supported in Windows 2000 and
Windows 98 Millennium to provide video decoding acceleratio n. Direct VA is the open standard
implementation of HVA, which is natively supported by the GMCH hardware.
5.4.8.2. Hardware Motion Compensation
The Hardware Motion Compensation (HWMC) process consists of reconstructing a new picture by
predicting (either forw ard, backward, or bi-directional) the resulting pixel colors from one or more
reference pictures. The GMCH receives the video stream and implements Motion Compensation and
subsequent steps in hardware. Performing Motion Compensation in hardware reduces the processor
demand of software-based MPEG-2 decoding, and thus improves system performance.
5.4.8.3. Sub-picture Support
Sub-picture is used for two purposes: Subtitles for movie captions, which are superimposed on a main
picture, and for Menus to provide some visual operation environments for the user.
DVD allows movie subtitles to be recorded as Sub-pictures. On a DVD disc, it is called “Subtitle”
because it has been prepared for storing captions. Since the disc can have a maximum of 32 tracks for
Subtitles, they can be used for variou s applications, for example, as Subtitles in different languages.
There are two kinds of Menus, the System Menus and other In-Title Menus. First, the System Menus are
displayed and operated at startup of or during the playback of the disc or from the stop state. Second, In-
Title menus can be programmed as a combination of Sub-picture and Highlight commands to be
displayed during playback of the disc.
The GMCH supports sub-picture for DVD and DBS by mixing the two video streams via alpha
blending. Unlike color keying, alpha blending provides a softer effect and each pixel that is displayed is
a composite between the two video stream pixels. The GMCH can utilize four methods when dealing
with sub-pictures. Th is flexibilit y means that the GMCH can work w ith all sub -p icture formats.
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5.5. Display Interface
The GMCH has three dedicated display ports: the analog port, the LFP LVDS interface, and Digital
display port, DVOC. DVOC can support TV-out encoders, external DACs, LVDS transmitters, and
TMDS transmitters. Each display port has control signals that may be used to control, configure and/or
determine the capabilities of an external device. The d ata that is sen t out the display ports are selected
from one of the two possible sources, display pipe A or display pipe B, except for the LVDS port which
can only be driven on Pipe B.
The GMCH’s digital display port is capable of driving a 165-MHz pixel clock on a single DVO port.
5.5.1. Analog Display Port Characteristics
The analog display po rt provides an RGB signal output along with an HSYNC and VSYNC signal.
There is an associated DDC signal pair that is implemented using GPIO pins dedicated to the analog
port. The intended target device is for a CRT based monitor with a VGA connector.
5.5.1.1. Integrated RAMDAC
The display function contains a 350-MHz integrated 24-bit RAM-based Digital-to-Analog Converter
(RAMDAC) that transforms up to 1600X1200 digital pixels (Intel 852GM/852GMV GMCH) at a
maximum refresh rate of 85 Hz. Three 8-bit DACs provide the R, G, and B signals to the monitor.
5.5.1.2. DDC (Display Data Channel)
DDC is defined by VESA. It allows communication between the host system and display. Both
configuration and control information can be exchanged allowing plug-and-play systems to be realized.
Support for DDC 1 and 2 is implemented.
5.5.2. Digital Display Interface
5.5.2.1. Dedicated LVDS Interface
The GMCH has a dedicated ANSI/TIA/EIA –644-1995 Specification compliant dual channel LFP
LVDS interface that can su pport TFT panel resolutions up to SXGA+ with a maxi mu m pixe l format of
18 bpp (with SSC supported frequency range from 25-MHz to 112-MHz (single channel/dual channel).
The display pipe selected by the LVDS display port is programmed with the panel timing parameters
that are determined by installed panel specifications or read from an onboard EDID ROM. The
programmed timing values are then “locked” into the registers to prevent unwanted corruption of the
values. From that point on, the display modes are changed by selecting a different source size for that
pipe, programming the VGA registers, or selecting a source size and enabling the VGA. The timing
signals will remain stable and active through mode chang es. Th ese mod e changes include VGA to
VGA, VGA to HiRes, HiRes to VGA, and HiRes to HiRes.
The transmitter can operate in a variety of modes and supports sev eral data formats. The serializer
supports 6-bit or 8-bit color and sing le or dual channel operating modes. The display stream from the
display pipe is sent to the LVDS transmitter port at the dot clock frequency, which is determined by the
panel timing requirements. The output of LVDS is running at a fixed multiple of the dot clock
frequency, which is determined by th e mode of operation; single or dual channel.
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Depending on configuration and mode, a single channel can take 18-bits of RGB pixel data plus 3 bits of
timing control (HSYNC/VSYNC/DE) an d output them on three differential data p air outputs; or 24 bits
of RGB plus 3 bits of timing control output on four differential data pair outputs. A dual channel
interface converts 36 bits or 48 bits of color information plus the 3 bits of timing contro l and outputs it
on six or eight sets of differential data outputs.
This display port is normally used in conjunction with the pipe functions of panel scaling and a 6-bit to
8-bit dither. This display port is also used in conjunction with the panel power sequencing and
additional associated fu nctions.
When enabled, the LVDS constant current drivers consume significant power. Individual pairs or sets of
pairs can be selected to be powere d dow n when not used. When disabl ed , indi vidual or sets of pairs wi l l
enter a low power state. When the port is disab led all pairs enters a low power mode. The panel power
sequencing can be set to override the selected power state of the drivers during power sequenci ng . For
more details on using the GMCH’s LFP LVDS interface for TFT Panel support, please refer to the
Common Panel Interfac e Specification, Rev 1.5 for details on:
CPIS Supported Resolutions
CPIS DC/AC Specifications
CPIS Pin Lists and Connectors
CPIS EDID Table Outline
CPIS Reference EDID Formats (XGA at 60-Hz Refresh Rate)
Sample CPIS EDID DTD’s (Primary Resolution at 60-Hz Refresh Rate)
Video Serialization Formats
References and External Standards
5.5.2.2. LVDS Interface Signals
LVDS for flat panel is compatible with the ANSI/TIA/EIA-644 specification. This is an electrical
standard only defining driver output characteristics and rece iver in put characteristics. There are two
LVDS transmitter channels (channel A and channel B) in the LVDS interface. Each channel consists of
four data pairs and a clock pair. The interface consists of a total of ten differential signal pairs of which
eight are data and two are clocks. The phase locked tr ansmit cloc k is transmitted in parallel with the data
being sent out over the data pairs and over the LVDS clock pair.
Each channel supports transmit clock frequency ranges from 25-MHz to 112-MHz, which provides a
throughput of up to 784-Mbps on each data output and up to 112-MP/s on the input. When using both
channels, they each operate at the same frequency each carrying a portion of the data. The maximum
pixel rate is increased to 224-MP/s but may be limited to less than that due to restrictions elsewhere in
the circuit.
The LVDS Port Enable bit enables or disables the entire LVDS interface. When the port is disabled, it
will be in a low power state. Once the port is enabled, individual driver pairs will b e disabled based on
the operating mode. Disabled drivers can be powered down for reduced power consumption or
optionally fixed to forced 0’s output.
5.5.2.3. LVDS Pair States
The LVDS pairs can be put into one of the following five states: powered down tri-state, powered down
Zero Volts, common mode, send zeros, or active. When in the active state, several data formats are
supported. When in powered down state, the circuit enters a low power state and dri ves ou t 0 V or tri-
states on both the output pins for the entire channel. The common mode tri-state is both pins of the pair
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set to the common mode voltage. When in the send zeros state, the circuit is powered up but sends only
zero for the pixel color data regardless what th e actual data is with the clock lines and timing signals
sending the normal clock and timing data.
5.5.2.4. Single Channel versus Dual Channel Mode
Both single channel and dual channel modes are available to allow interfacing to either single or dual
channel panel interfaces. This LVDS port can operate in single channel or dual channel mode. Dual
channel mode uses twice the number of LVDS pairs and transfers the pixel data at twice the rate of the
single channel. In general, one channel will be us ed for even pixels and the other for odd pixel data.
The first pixel of the line is determined by the display enable going active and th at pixel will be sent out
channel A. All horizontal timings for active, sync, and blank will be limited to be on two pixe l
boundaries in the two channel modes.
5.5.2.5. LVDS Channel Skew
When in dual channel mode, the two channels must meet the panel requirements with respect to the inter
channel skew.
5.5.2.6. LVDS PLL
The Display PLL is used to synthesize the clocks that control transmission of the data across the LVDS
interface. The three operations that are controlled are the pixel rate, the load rate, and the IO shift rate.
These are synchronized to each other and have specific ratios based on single channel or dual channel
mode. If the pixel clock is considered the 1x rate, a 7x or 3.5x speed IO_shift clock needed for the high-
speed, serial outputs settin g the data rate of the transmitters. The load clock will h ave either a 1x or .5x
ratio to the pixel clock.
5.5.2.7. SSC Support
The GMCH is designed to tolerate 0.5%, 1.0%, and 2.5% down/center spread at a modulation rate from
30-50kHz triangle. An external SSC clock synthesizer can be used to provide the 48/66-MHz reference
clock into the GMCH Pipe B PLL.
5.5.2.8. Panel Power Sequencing
This section provides details for the power sequence timing relationship of the panel power, the
backlight enab le and the LVDS data timing deliv ery. In order to meet the pan e l power timing
specification requirements, two signals, PANELVDDEN and PANELBKLTEN are provided to control
the timing sequencing function of the panel and the backlight power supplies.
5.5.2.8.1. Panel Power Sequence States
A defined power sequence is recommended when enabling the panel or disabling the panel. Th e set of
timing parameters can vary from panel to panel vendor, provided that they stay within a predefined
range of values. The panel VDD power, the backlight on/off state and the LVDS clock and data lines
are all managed by an internal power sequencer.
A requested power-up sequence is only allowed to begin after the power cycle delay time requirement
T4 is met.
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Figure 7. Panel Power Sequencing
Power On Sequence from off state and
Power Off Sequence after full On
Panel VDD
Enable
Panel
BackLight
Enable
Clock/Data Lines
T1+T2 T5 T3
Valid
T4
Panel
On
Off Off
TX
T4
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Table 29. Panel Power Sequencing Timing Parameters
Panel Power Sequence Timing Parameters
Name Spec Name From To
T1+T2 Vdd On to LVDS Active
Panel Vdd must be on for a minimum time before the LVDS data
stream is enabled.
.1 Vdd LVDS Active
T5 Backlight
LVDS data must be enabled for a minimum time before the backlight is
turned on.
LVDS Active Backlight on
TX Backlight State
Backlight must be disabled for a minimum time before the LVDS data
stream is stopped.
Backlight Off LVDS off
T3 LVDS State
Data must be off for a minimum time before the panel VDD is turned
off.
LVDS Off Start power off
T4 Power cycle Delay
When panel VDD is turned from On to Off, a minimum wait must be
satisfied before the panel VDD is enabled again.
Power Off Power On
Sequence
Start
5.5.2.9. Back Light Inverter Control
The GMCH offers integrated PWM for TFT panel Backlight Inverter control. Other methods of control
are specified in the Common Panel Interface Specification, Version 1.5.
PWM – based Backlight Brig htness Control
SMBus-based Backlight Brightness Control
DBL (Display Brightness Link) –to- VDL (Video Data Link) Power Sequencing
5.5.2.10. Digital Video Output Port
The GMCH has the capability to support additional d igital display devices (e.g. TMDS transmitter,
LVDS transmitter or TV-out encoder) through its digital video output port. DVOC can deliver a 165-
MHz dot clock on its 12-bit interface.
The digital display port consists of a digital data bus, VSYNC, HSYNC, and BLANK# signals. The data
bus can operate only in a 12-bit mode. Embedded sync information or HSYNC and VSYNC signals can
optionally provide the basic timing information to the external d ev ice and the BLANK# signal indicates
which clock cycles contain valid data. The BLANK# signal can be optionally selected to includ e the
border area of the timing. The VSYNC and HSYNC signals can be di sabl ed when embedded sync
information is to be used or to support DPMS. Optionally a STA LL signal can cau s e the nex t line of data
to not be sent until the STALL signal is remov ed. Op tionally the FIELD pin can indicate to the overlay
which field is currently being displayed at the display device.
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6. Power and Thermal Management
The Intel 852GM/852GMV GMCH platform is intended to be complian t with the following
specifications and technologies:
APM Rev 1.2
PCI Power Management Rev 1.0
PC’99, Rev 1.0, PC’99A, and PC’01, Rev 1.0
ACPI 1.0b and 2.0 sup port
ACPI S0, S1-M, S3, S4, S5, C0, C1, C2, C3 states
Internal Graphics Adapter D0, D1, D3 (Hot/Cold)
Enhanced Intel SpeedStep
®
Technology
On Die Thermal Sensor, enabling core and System Memory write thermal throttling for prevention
of catastrophic thermal conditions
External Thermal Sensor Input pin
Enabling SO-DIMM thermal throttling
C4 compatible (C4 = Deeper sleep) is same as C3 from the GMCH perspective, but from p latfo rm
perspective, CPU v ol t a ge is r e duced during C3 and S1-M entry to minimum to maintain state)
The GMCH also reduces I/O power dynamically, by disabling sense amps on input buffers, as
well as tristating output buffers when possible
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6.1. General Description of Supported CPU States
C0 (Full On): This is th e only state that runs software. All clocks are running, STPCLK is deasserted,
and the processor core is active. The processor can service snoops and maintain cache coherency in this
state.
C1 (Auto Halt): The first level of power reduction occurs when the processor executes an Auto-Halt
instruction. This stops the execution of the instruction stream and reduces the processor’s power
consumption. The processor can service snoops and maintain cache coherency in this state.
C2 (Stop Grant): To enter this low power state, STPCLK is asserted. The processor can still service
snoops and maintain cache coherency in this state.
C3 (Sleep or Deep Sleep): In these states the processor clock is stopped. The GMCH assumes that no
Hub Interface cycles (except special cycles) will occur while the GMCH is in this state. The processor
cannot snoop its caches to maintain coherency while in the C3 state. The GMCH will transition from the
C0 state to the C3 state when software reads the Level 3 Register. This is an ACPI defined register but
BIOS or APM (via BIOS) can use this facility when entering a low power state. The Host Clock PLL
within the GMCH can be programmed to be shut off for increased power savings and the GMCH uses
the DPSLP signal input for this purpose.
C4 (Deeper Sleep): The C4 state appears to the GMCH as identical to the C3 state, but in this state the
processor core voltage is lowered. There are no internal events in GMCH fo r the C4 state that differ
from the C3 state (this state is not supported for Intel Celeron M pro cessor and mobile Intel Celeron
processor).
6.2. General Description of ACPI States
Internal Graphics Adapter:
D0 Full on, display activ e
D1 Low power state, low latency recovery. No display, System Memory retained
D3 Hot - All state lost other than PCI config. System Memory lost (optionally)
D3 Cold - Power off
CPU:
C0 Full On
C1 Auto Halt
C2 Desktop Stop Clock. Clk to CPU still running. Clock stopped to CPU co re.
C3 Deep Sleep. Clock to CPU stopped.
C4 Deeper Sleep. Same as C3 with reduced voltage on the CPU.
System States
• G0/S0 Full On
• G1/S1-M Power On Suspend (POS). System Context Preserved
• G1/S2 Not suppo rted.
• G1/S3 Suspend to RAM (STR). Power and context lost to chipset.
• G1/S4 Susp end to Disk (STD). All power lost (except wakeup on ICH4-M)
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• G2/S5 Hard off. Total reboot.
6.3. Enhanced Intel SpeedStep Technology Overview
With Enhanced Intel SpeedStep Technology the processor core voltage changes and allows true CPU
core frequency changes versus only clock throttling.
Note: Enhanced Intel Speed Step technology is not supported for Intel Celeron M pro cessor, mob ile Intel
Celeron processor and Intel Celeron D processor on 90 nm process and in the 478-pin package.
Table 30. Enhanced Intel SpeedStep Technology Overview
CPU Mobile Intel Pentium 4 Processor-M
Benefit Over Non-power Managed CPU Additional lower voltages and frequencies
Transition Prompt OS based on CPU load demand, thermal control, or user event based
CPU Availability CPU unavailability can be restricted to ~250 µs (CPU dependent) by s/w
6.4. Internal Thermal Sensor
This section describes the new on-die thermal sensor capability. The thermal sensor functions are
provide d bel ow:
Catastrophic Trip Point: This trip point is programmed through the BIOS du ring in itialization. This
trip point is set at the temperature at which the GMCH should be shut down immediately with minimal
software support. The settings for this are lockable.
High Temperature Trip Point: This trip point is nominally 14ºC below the Catastrophic Trip Point.
The BIOS can be programmed to provide an interrupt when it is crossed in either direction. Upon the trip
event, hardware throttling may be enab led when the temperature is exceeded.
6.4.1. Hardware Throttling
The Hot trip points’ crossings events may be used to trigger throttling w ithout intervention b y software.
System Memory write throttling may be enabled on Hot trip points. The HTC register selects wh ether it
is Catastrophic or both that enable thro ttling. System Memory write throttling registers in Device #0
configuration space determine whether throttling is enabled at all.
6.4.2. Register Locking
TCO contains a lock bit that locks the catastrophic programming interface, includ ing TCO, TCTS, and
two bits in TSCR that could disable the sensor or alter the trip point. HTC has a lo ck bit for the hardware
throttling settings.
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6.4.3. Hysteresis Operation
Hysteresis provides a small amount of positive feedback to the thermal sensor circuit to prevent a trip
point from flipping back and forth rapidly when the temperature is right at the trip point.
6.5. External Thermal Sensor Input
An external thermal sensor with a serial interface may be placed next to DDR SDRAM SO-DIMM (or
any other appropriate platform location), or a remote Thermal Diode may be placed next to the SO-
DIMM (or any other appropriate platform location) and connected to the external Thermal sensor. Intel
advises that the external Thermal sensor co ntains some form of hysteresis, since none is provided by the
GMCH hardware.
The external sensor can be connected to the ICH4-M via the SMBus Interface to allow programming and
setup by BIOS software over the serial interface. The external sensor’s output should include an Active-
Low Open-Drain signal indicating an Over-Temp condition, wh ich remains asserted for as long as the
Over-Temp Condition exists, and deasserts when temperature has returned to w ithin normal operating
range. This external sensor outp ut will be connected to the GMCH input (EXTTS_0) and will trigger a
preset interrupt and/or read-throttle on a level-sensitiv e basis.
Additional external thermal sensor’s outputs, fo r multiple sensors, can be wire-ORed together allow
signaling from multiple sensors located physically separately. Software can, if necessary, distinguish
which SO-DIMM(s) is the source of the over-temp through the serial interface. However, since the SO-
DIMM(s) will be located on the same System Memory Bus Da ta lines, any GMCH-based Read Throttle
will apply equally.
Note: The use of external sensors that include an internal pull-up resistor on the open-drain th ermal trip output
is discouraged. However, it may be possible depending on the size of the pull-up and the voltage of the
sensor. Please refer to the platform design guide for mo re information.
6.5.1. Usage
External Sensor(s) Used for Dynamic Temperature Feedback Control in production releases:
Sensor on SO-DIMMs, which can be us ed to dynamically control read throttling.
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7. Testability
In the Intel 852GM/852GMV GMCH, testab ility for Au tomated Test Equipment (ATE) board level
testing has been implemented as an XOR chain. An XOR-tree is a chain of XOR gates, each with one
input pin connected to it. The XOR Chain test mode is used by product engineers during manufacturing
and OEMs during board level connectivity tests. The main purpose of th is test mode is to detect
connectivity shorts between adjacent pins and to check proper bonding between I/O pads and I/O pins.
Figure 8. XOR–Tree Chain
Input
XOR
Out
xor.vsd
Input
Input Input Input
VCC1_2
The algorithm used for in–circuit test is as follo ws:
1. Drive all input pins to an initial logic level 1. Observ e the output corresponding to scan chain
being tested.
2. Toggle pins one at a time starting from the first pin in th e chain, continuing to the last pin, from its
initial logic level to the opposite logic level. Observe the output changes with each pin toggle.
7.1. XOR Test Mode Entry
Please refer to XOR Chain Test Mode Entry Events Diagram in Figure 9.
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Figure 9. XOR Chain Test Mode Entry Events Diagram
powerok
LCLKCTLA
HSYNC
Don't care
Don't care
RSTIN#
(PCI reset)
Don't care
VSYNC
Note: HSYNC and LCLKCTLA = XOR Chain Test Mode Activation; No clock is required for XOR Chain
Test Mode. A minimum of 50 ns PW ROK assertion prior to RSTIN# assertion is recommended. A
minimum of 10 ns VSYNC/HSYNC/LCLKCTLA assertion prior to PWROK assertion is reco mmended.
Please refer to ALLZ Test Mode Entry Events Diagram in Figure 10.
Figure 10. ALLZ Test Mode Entry Ev ents Diagram
powerok
LCLKCTLA
Don't care
HSYNC
VSYNC
Don't care
Don't care
RSTIN#
(PCI reset)
NOTE: VSYNC and LCLKCTLA = ALL Z Test Mode Activation; No clock is required for ALLZ Test Mode Activation.
A minimum of 50 ns PWROK assertion prior to RSTIN# assertion is recommended. A minimum of 10 ns
VSYNC/HSYNC/LCLKCTLA assertion prior to PWROK assertion is recommended.
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7.2. XOR Chain Differential Pairs
Table 31 provides differential signals in the XOR chains that must be treated as pairs. Pin1 and Pin2 as
shown below need to drive to the opp osite value always.
Table 31. Differential Signals in the XOR Chains
Pin1 Pin2 XOR Chain
DVOCCLK# DVOCCLK DVO XOR 2
HLSTB# HLSTB HUB XOR
7.3. XOR Chain Exclusion List
See Table 32 for a list of pins that are not included in the XOR chains (excluding all VCC/VSS/VTT).
Note: Connectivity column is used to identify what need to be driven on that particular pin during XOR chain
test mode.
Table 32. XOR Chain Exclusion List of Pins
Item# IN/OUT Ball Pin/VHDL I/O Type Voltage Connectivity
1 IN Y3 GCLKIN PLL CLK 3.3 0
2 - W1 HLVREF Analog 1/3 VCCHL 0.4
3 - T2 HLRCOMP Analog N/A N/A
4 - U2 PSWING Analog N/A N/A
5 - F1 GVREF Analog 1/2 VCCDVO 0.75
6 - D1 DVORCOMP Analog N/A N/A
7 IN J11 PWROK CMOS 3.3 N/A
8 IN B7 DREFCLK PLL CLK 3.3 0
9 - E8 REFSET Analog N/A N/A
10 - C9 BLUE Analog N/A N/A
11 - D9 BLUE# Analog N/A N/A
12 - C8 GREEN Analog N/A N/A
13 - D8 GREEN# Analog N/A N/A
14 A7 RED Analog N/A N/A
15 - A8 RED# Analog N/A N/A
16 - D12 LVREFH Analog 1.1 1.1
17 - A10 LIBG Analog N/A N/A
18 - B12 LVBG Analog N/A N/A
19 - F12 LVREFL Analog 1.1 1.1
20 IN B17 DREFSSCLK PLL CLK 3.3 0
21 - J17 HDVREF[2] Analog 2/3 VTTLF 1.0
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Item# IN/OUT Ball Pin/VHDL I/O Type Voltage Connectivity
22 - B20 HXRCOMP Analog N/A N/A
23 - B18 HXSWING Analog N/A N/A
24 - J21 HDVREF[1] Analog 2/3 VTTLF 1.0
25 IN AD29 BCLK# Diff 0.7 0
26 IN AE29 BCLK Diff 0.7 0.7
27 - K21 HDVREF[0] Analog 2/3 VTTLF 1.0
28 - Y28 HCCVREF Analog 2/3 VTTLF 1.0
29 - Y22 HAVREF Analog 2/3 VTTLF 1.0
30 - H28 HYRCOMP Analog N/A N/A
31 - K28 HYSWING Analog N/A N/A
32 IN D28 RSTIN# CMOS 3.3 N/A
33 - AJ24 SMVREF_0 Analog 1/2 VCCSM 1.25
34 - AB1 SMRCOMP Analog N/A N/A
7.4. XOR Chain Connectivity/Ordering
The following tables contain the ordering for all of the Intel 852GM/852GMV GMCH XOR chains and
pin to ball mapping information:
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Table 33. XOR Mapping
XOR Chain DVO 1
DVO IN/OUT Ball Pin/VHDL I/O Type Voltage
XOR Out
OUT AB5 SMA[12] SSTL_2 2.5
1 INOUT T6 RSVD DVO 1.5
2 INOUT T5 RSVD DVO 1.5
3 INOUT T7 MDDCDATA DVO 1.5
4 INOUT R3 RSVD DVO 1.5
5 INOUT R4 RSVD DVO 1.5
6 INOUT R6 RSVD DVO 1.5
7 INOUT R5 RSVD DVO 1.5
8 INOUT P2 RSVD DVO 1.5
9 INOUT P4 RSVD DVO 1.5
10 INOUT P3 RSVD DVO 1.5
11 INOUT P6 RSVD N/A N/A
12 INOUT P5 RSVD N/A N/A
13 INOUT N2 RSVD N/A N/A
14 INOUT N3 RSVD N/A N/A
15 INOUT M1 RSVD N/A N/A
16 INOUT N5 RSVD N/A N/A
17 INOUT M2 RSVD N/A N/A
18 INOUT M5 RSVD N/A N/A
19 INOUT M3 DVOBCCLKINT DVO 1.5
20 INOUT L2 RSVD N/A N/A
21 INOUT P7 MDDCCLK DVO 1.5
22 INOUT N6 MI2CDATA DVO 1.5
23 INOUT M6 MDVIDATA DVO 1.5
24 INOUT N7 MDVICLK DVO 1.5
25 INOUT L7 DVODETECT DVO 1.5
26 INOUT K7 MI2CCLK DVO 1.5
27 OUT B2 RSVD N/A N/A
28 IN B3 RSVD N/A N/A
XOR Chain DVO 2
DVO IN/OUT Ball Pin/VHDL I/O Type Voltage
XOR Out
OUT AD5 SMA[11] SSTL_2 2.5
1 INOUT L3 DVOCBLANK# DVO 1.5
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INOUT K1 DVOCD[1] DVO 1.5
3 INOUT L4 RSVD DVO N/A
4 INOUT L5 DVOCVSYNC DVO 1.5
5 INOUT K2 DVOCD[3] DVO 1.5
6 INOUT K5 DVOCD[0] DVO 1.5
7 INOUT K3 DVOCD[2] DVO 1.5
8 INOUT J2 DVOCCLK# DVO 1.5
9 INOUT J3 DVOCCLK DVO 1.5
10 INOUT H2 DVOCD[6] DVO 1.5
11 INOUT J5 DVOCD[5] DVO 1.5
12 INOUT H1 DVOCD[7] DVO 1.5
13 INOUT J6 DVOCD[4] DVO 1.5
14 INOUT K6 DVOCHSYNC DVO 1.5
15 INOUT H4 DVOCD[9] DVO 1.5
16 INOUT H3 DVOCD[8] DVO 1.5
17 INOUT H5 DVOCFLDSTL DVO 1.5
18 INOUT H6 DVOCD[10] DVO 1.5
19 INOUT G2 DVOBCINT# DVO 1.5
20 INOUT G3 DVOCD[11] DVO 1.5
21 IN D2 RSVD N/A N/A
22 IN D3 RSVD N/A N/A
23 IN F4 ADDID[5] DVO 1.5
24 IN F5 ADDID[1] DVO 1.5
25 IN F6 ADDID[7] DVO 1.5
26 IN E2 ADDID[3] DVO 1.5
27 IN E5 ADDID[0] DVO 1.5
28 IN F3 RSVD N/A N/A
29 IN F2 RSVD N/A N/A
30 OUT C2 RSVD N/A N/A
31 IN E3 ADDID[2] DVO 1.5
32 OUT C3 GST[1] DVO 1.5
33 OUT C4 GST[0] DVO 1.5
34 IN G5 ADDID[4] DVO 1.5
35 IN G6 ADDID[6] DVO 1.5
36 IN D5 DPMS DVO 1.5
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XOR Chain FSB 1
IN/OUT Ball Pin I/O Type Voltage
XOR Out
OUT AC19 SMA[10] SSTL_2 2.5
1 INOUT D16 HD[62]# GTL+ 1.5
2 INOUT C16 HD[60]# GTL+ 1.5
3 INOUT G16 HD[58]# GTL+ 1.5
4 INOUT C17 HD[55]# GTL+ 1.5
5 INOUT E17 HD[61]# GTL+ 1.5
6 INOUT E16 HD[59]# GTL+ 1.5
7 INOUT F17 HD[56]# GTL+ 1.5
8 INOUT B19 HD[57]# GTL+ 1.5
9 INOUT E18 HDSTBP[3]# GTL+ 1.5
10 INOUT D18 HDSTBN[3]# GTL+ 1.5
11 INOUT C18 HD[63]# GTL+ 1.5
12 INOUT G17 HD[51]# GTL+ 1.5
13 INOUT C19 HD[54]# GTL+ 1.5
14 INOUT D20 HD[52]# GTL+ 1.5
15 INOUT E20 HD[50]# GTL+ 1.5
16 INOUT E19 HD[49]# GTL+ 1.5
17 INOUT G19 DINV[3]# GTL+ 1.5
18 INOUT F19 HD[53]# GTL+ 1.5
19 INOUT G18 HD[48]# GTL+ 1.5
20 INOUT B21 HD[32]# GTL+ 1.5
21 INOUT C20 HD[46]# GTL+ 1.5
22 INOUT C23 HD[35]# GTL+ 1.5
23 INOUT B23 HD[43]# GTL+ 1.5
24 INOUT B22 HD[42]# GTL+ 1.5
25 INOUT B25 DINV[2]# GTL+ 1.5
26 INOUT D22 HD[36]# GTL+ 1.5
27 INOUT C24 HD[34]# GTL+ 1.5
28 INOUT C21 HD[47]# GTL+ 1.5
29 INOUT E21 HDSTBP[2]# GTL+ 1.5
30 INOUT E22 HDSTBN[2]# GTL+ 1.5
31 INOUT D24 HD[39]# GTL+ 1.5
32 INOUT C25 HD[37]# GTL+ 1.5
33 INOUT F21 HD[45]# GTL+ 1.5
34 INOUT E24 HD[38]# GTL+ 1.5
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INOUT E23 HD[41]# GTL+ 1.5
36 INOUT G21 HD[33]# GTL+ 1.5
37 INOUT F23 HD[44]# GTL+ 1.5
38 INOUT G20 HD[40]# GTL+ 1.5
39 OUT M27 RS[2]# GTL+ 1.5
40 OUT P28 BPRI# GTL+ 1.5
41 OUT AA22 DPWR# GTL+ 1.5
42 INOUT AA26 HADSTB[1]# GTL+ 1.5
XOR Chain FSB 2
IN/OUT Ball Pin I/O Type Voltage
XOR Out
OUT AC5 SMA[9] SSTL_2 2.5
1 INOUT E25 DINV[1]# GTL+ 1.5
2 INOUT B26 HD[26]# GTL+ 1.5
3 INOUT C26 HD[28]# GTL+ 1.5
4 INOUT B27 HD[18]# GTL+ 1.5
5 INOUT B28 HD[31]# GTL+ 1.5
6 INOUT G23 HD[30]# GTL+ 1.5
7 INOUT E26 HD[9]# GTL+ 1.5
8 INOUT D26 HDSTBP[1]# GTL+ 1.5
9 INOUT C27 HDSTBN[1]# GTL+ 1.5
10 INOUT G22 HD[27]# GTL+ 1.5
11 INOUT G24 HD[24]# GTL+ 1.5
12 INOUT C28 HD[25]# GTL+ 1.5
13 INOUT E27 HD[20]# GTL+ 1.5
14 INOUT F2 HD[17]# GTL+ 1.5
15 INOUT D27 HD[23]# GTL+ 1.5
16 INOUT G25 HD[21]# GTL+ 1.5
17 INOUT F25 HD[16]# GTL+ 1.5
18 INOUT H23 HD[19]# GTL+ 1.5
19 INOUT F28 HD[22]# GTL+ 1.5
20 INOUT K23 HD[11]# GTL+ 1.5
21 INOUT J23 HD[14]# GTL+ 1.5
22 INOUT H25 HD[10]# GTL+ 1.5
23 INOUT G27 HD[12]# GTL+ 1.5
24 INOUT K22 HD[0]# GTL+ 1.5
25 INOUT H26 HD[15]# GTL+ 1.5
26 INOUT G28 HD[5]# GTL+ 1.5
27 INOUT H27 HD[1]# GTL+ 1.5
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INOUT J24 HD[9]# GTL+ 1.5
29 INOUT L23 HD[7]# GTL+ 1.5
30 INOUT K25 HD[2]# GTL+ 1.5
31 INOUT K27 HDSTBP[0]# GTL+ 1.5
32 INOUT J28 HDSTBN[0]# GTL+ 1.5
33 INOUT J25 DINV[0]# GTL+ 1.5
34 INOUT K26 HD[13]# GTL+ 1.5
35 INOUT L24 HD[3]# GTL+ 1.5
36 INOUT L25 HD[8]# GTL+ 1.5
37 INOUT L27 HD[6]# GTL+ 1.5
38 INOUT J27 HD[4]# GTL+ 1.5
39 OUT M28 DEFER# GTL+ 1.5
40 OUT N23 RS[0]# GTL+ 1.5
41 OUT P26 RS[1]# GTL+ 1.5
42 INOUT T26 HADSTB[0]# GTL+ 1.5
XOR Chain FSB 3
IN/OUT Ball Pin I/O Type Voltage
XOR Out
OUT AC6 SMA[8] SSTL_2 2.5
1 OUT F15 CPURST# GTL+ 1.5
2 IN Y23 DPSLP# CMOS 1.5
3 INOUT N27 HIT# GTL+ 1.5
4 INOUT N28 HITM# GTL+ 1.5
5 INOUT N25 BNR# GTL+ 1.5
6 INOUT N24 DRDY# GTL+ 1.5
7 IN P27 HLOCK# GTL+ 1.5
8 INOUT M23 BREQ0# GTL+ 1.5
9 OUT M25 HTRDY# GTL+ 1.5
10 INOUT M26 DBSY# GTL+ 1.5
11 INOUT L28 ADS# GTL+ 1.5
12 INOUT R28 HREQ[0]# GTL+ 1.5
13 INOUT P25 HREQ[1]# GTL+ 1.5
14 INOUT T28 HA[5]# GTL+ 1.5
15 INOUT R27 HA[6]# GTL+ 1.5
16 INOUT R23 HREQ[2]# GTL+ 1.5
17 INOUT R24 HA[9]# GTL+ 1.5
18 INOUT T27 HA[13]# GTL+ 1.5
19 INOUT U28 HA[10]# GTL+ 1.5
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INOUT P23 HA[3]# GTL+ 1.5
21 INOUT T25 HA[4]# GTL+ 1.5
22 INOUT R25 HREQ[3]# GTL+ 1.5
23 INOUT V27 HA[14]# GTL+ 1.5
24 INOUT U27 HA[12]# GTL+ 1.5
25 INOUT V28 HA[11]# GTL+ 1.5
26 INOUT T23 HREQ[4]# GTL+ 1.5
27 INOUT U24 HA[8]# GTL+ 1.5
28 INOUT U23 HA[7]# GTL+ 1.5
29 INOUT V26 HA[16]# GTL+ 1.5
30 INOUT U25 HA[15]# GTL+ 1.5
31 INOUT V25 HA[18]# GTL+ 1.5
32 INOUT Y26 HA[30]# GTL+ 1.5
33 INOUT W28 HA[28]# GTL+ 1.5
34 INOUT W25 HA[20]# GTL+ 1.5
35 INOUT V23 HA[19]# GTL+ 1.5
36 INOUT W27 HA[25]# GTL+ 1.5
37 INOUT Y25 HA[21] GTL+ 1.5
38 INOUT W24 HA[23]# GTL+ 1.5
39 INOUT Y27 HA[26]# GTL+ 1.5
40 INOUT Y24 HA[17]# GTL+ 1.5
41 INOUT AA27 HA[22]# GTL+ 1.5
42 INOUT W23 HA[24]# GTL+ 1.5
43 INOUT AB28 HA[31]# GTL+ 1.5
44 INOUT AB27 HA[29]# GTL+ 1.5
45 INOUT AA28 HA[27] GTL+ 1.5
XOR Chain GPIO
IN/OUT Ball Pin I/O Type Voltage
XOR Out
OUT AD7 SMA[7] SSTL_2 2.5
1 OUT G8 PANELBKLTCTL CMOS 3.3
2 OUT F8 PANELBKLTEN CMOS 3.3
3 OUT C6 LCLKCTLB CMOS 3.3
4 IN D6 EXTTS_0 CMOS 3.3
5 OUT F7 AGPBUSY# CMOS 3.3
6 IN D7 RSVD N/A N/A
7 INOUT C5 DDCPDATA CMOS 3.3
8 INOUT B4 DDCPCLK CMOS 3.3
9 OUT H10 HSYNC CMOS 3.3
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OUT A5 PANELVDDEN CMOS 3.3
11 INOUT B6 DDCACLK CMOS 3.3
12 OUT J9 VSYNC CMOS 3.3
13 INOUT G9 DDCADATA CMOS 3.3
14 OUT H9 LCLKCTLA CMOS 3.3
XOR Chain HUB
IN/OUT Ball Pin I/O Type Voltage
XOR Out
OUT AD8 SMA[6] SSTL_2 2.5
1 INOUT W2 HL[4] HL1.5 1.2
2 INOUT W6 HL[5] HL1.5 1.2
3 INOUT W7 HL[7] HL1.5 1.2
4 INOUT V6 HL[6] HL1.5 1.2
5 INOUT W3 HLSTB HL1.5 1.2
6 INOUT V2 HLSTB# HL1.5 1.2
7 IN V5 Hl[9] HL1.5 1.2
8 INOUT V4 HL[10] HL1.5 1.2
9 INOUT V3 HL[3] HL1.5 1.2
10 INOUT U4 HL[1] HL1.5 1.2
11 INOUT U3 HL[2] HL1.5 1.2
12 INOUT U7 HL[0] HL1.5 1.2
13 OUT T3 HL[8] HL1.5 1.2
XOR Chain LVDS
IN/OUT Ball Pin I/O Type Voltage
XOR Out
OUT AD17 SMA[3] SSTL_2 2.5
1 INOUT F10 ICLKBP LVDS 1.5
2 INOUT E10 ICLKBM LVDS 1.5
3 INOUT G10 IYBP[3] LVDS 1.5
4 INOUT G11 IYBM[3] LVDS 1.5
5 INOUT G12 IYBP[0] LVDS 1.5
6 INOUT H12 IYBM[0] LVDS 1.5
7 INOUT E11 IYBP[1] LVDS 1.5
8 INOUT E12 IYBM[1] LVDS 1.5
9 INOUT C11 IYBP[2] LVDS 1.5
10 INOUT C12 IYBM[2] LVDS 1.5
11 INOUT E13 ICLKAP LVDS 1.5
12 INOUT D14 ICLKAM LVDS 1.5
13 INOUT B13 IYAP[3] LVDS 1.5
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INOUT C13 IYAM[3] LVDS 1.5
15 INOUT F14 IYAP[0] LVDS 1.5
16 INOUT G14 IYAM[0] LVDS 1.5
17 INOUT C14 IYAP[2] LVDS 1.5
18 INOUT C15 IYAM[2] LVDS 1.5
19 INOUT E14 IYAP[1] LVDS 1.5
20 INOUT E15 IYAM[1] LVDS 1.5
XOR Chain SM1
DDR SDRAM
IN/OUT Ball Pin I/O Type Voltage
XOR Out
OUT AD23 SCS[0]# SSTL_2 2.5
1 INOUT AE27 SDQ[62] SSTL_2 2.5
2 INOUT AD27 SDQ[63] SSTL_2 2.5
3 INOUT AF26 SDQ[61] SSTL_2 2.5
4 INOUT AG26 SDQ[60] SSTL_2 2.5
5 OUT AC25 SCS[3]# SSTL_2 2.5
6 OUT AD24 SDM[6] SSTL_2 2.5
7 INOUT AH24 SDQS[6] SSTL_2 2.5
8 OUT AD25 SWE# SSTL_2 2.5
9 OUT AC18 SMA[0] SSTL_2 2.5
10 INOUT AH17 SDQS[4] SSTL_2 2.5
11 OUT AD19 SDM[4] SSTL_2 2.5
12 CLK AC26 SCK[1] SSTL_2 2.5
13 CLK AB23 SCK[4] SSTL_2 2.5
14 CLK AA3 SCK[5] SSTL_2 2.5
15 CLK AC2 SCK[3] SSTL_2 2.5
16 CLK AB2 SCK[0] SSTL_2 2.5
17 CLK AC3 SCK[2] SSTL_2 2.5
18 OUT AH15 SDM[8] SSTL_2 2.5
19 INOUT AF17 RSVD N/A N/A
20 INOUT AF16 RSVD N/A N/A
21 INOUT AG16 RSVD N/A N/A
22 INOUT AE15 RSVD N/A N/A
23 INOUT AH14 RSVD N/A N/A
24 INOUT AE17 RSVD N/A N/A
25 INOUT AD15 SDQS[8] SSTL_2 2.5
26 INOUT AE14 RSVD N/A N/A
27 INUT AG14 RSVD N/A N/A
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INOUT AH8 SDQS[2] SSTL_2 2.5
29 OUT AE9 SDM[2] SSTL_2 2.5
30 OUT AC7 SCKE[0] SSTL_2 2.5
31 INOUT AG2 SDQS[0] SSTL_2 2.5
32 OUT AE5 SDM[0] SSTL_2 2.5
XOR Chain SM2
DDR SDRAM
IN/OUT Ball Pin I/O Type Voltage
XOR Out
OUT AD26 SCS[1]# SSTL_2 2.5
1 INOUT AF28 SDQ[59] SSTL_2 2.5
2 INOUT AG28 SDQ[58] SSTL_2 2.5
3 INOUT AH27 SDQS[7] SSTL_2 2.5
4 OUT AH28 SDM[7] SSTL_2 2.5
5 INOUT AE26 SDQ[57] SSTL_2 2.5
6 INOUT AH26 SDQ[56] SSTL_2 2.5
7 INOUT AH25 SDQ[51] SSTL_2 2.5
8 INOUT AG25 SDQ[55] SSTL_2 2.5
9 INOUT AF25 SDQ[54] SSTL_2 2.5
10 INOUT AE24 SDQ[50] SSTL_2 2.5
11 INOUT AH23 SDQ[49] SSTL_2 2.5
12 INOUT AF23 SDQ[53] SSTL_2 2.5
13 INOUT AE23 SDQ[48] SSTL_2 2.5
14 INOUT AG23 SDQ[52] SSTL_2 2.5
15 INOUT AE21 SDQS[5] SSTL_2 2.5
16 OUT AD21 SDM[5] SSTL_2 2.5
17 OUT AD20 SBA[1] SSTL_2 2.5
18 OUT AD22 SBA[0] SSTL_2 2.5
19 OUT AC21 SRAS# SSTL_2 2.5
20 OUT AC15 RCVENOUT# SSTL_2 2.5
21 INOUT AC16 RCVENIN# SSTL_2 2.5
22 CLK AB24 SCK[4]# SSTL_2 2.5
23 CLK AB25 SCK[1]# SSTL_2 2.5
24 CLK AB4 SCK[5]# SSTL_2 2.5
25 CLK AA2 SCK[0]# SSTL_2 2.5
26 CLK AD2 SCK[3]# SSTL_2 2.5
27 CLK AD4 SCK[2]# SSTL_2 2.5
28 OUT AD10 SMAB[5] SSTL_2 2.5
29 OUT AD14 SMA[1] SSTL_2 2.5
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OUT AD16 SMAB[1] SSTL_2 2.5
31 OUT AD13 SMA[2] SSTL_2 2.5
32 OUT AF11 SMAB[4] SSTL_2 2.5
33 OUT AC12 SMAB[2] SSTL_2 2.5
34 OUT AC13 SMA[5] SSTL_2 2.5
35 INOUT AE12 SDQS[3] SSTL_2 2.5
36 OUT AH12 SDM[3] SSTL_2 2.5
37 OUT AD11 SMA[4] SSTL_2 2.5
38 OUT AC10 SCKE[3] SSTL_2 2.5
39 OUT AE6 SDM[1] SSTL_2 2.5
40 INOUT AH5 SDQS[1] SSTL_2 2.5
41 OUT AC9 SCKE[2] SSTL_2 2.5
42 OUT AB7 SCKE[1] SSTL_2 2.5
XOR Chain SM 3
DDR SDRAM
IN/OUT Ball Pin I/O Type Voltage
XOR Out
OUT AC22 SCS[2]# SSTL_2 2.5
1 OUT AC24 SCAS# SSTL_2 2.5
2 INOUT AG22 SDQ[47] SSTL_2 2.5
3 INOUT AH22 SDQ[43] SSTL_2 2.5
4 INOUT AF22 SDQ[42] SSTL_2 2.5
5 INOUT AG20 SDQ[41] SSTL_2 2.5
6 INOUT AF20 SDQ[44] SSTL_2 2.5
7 INOUT AH21 SDQ[46] SSTL_2 2.5
8 INOUT AH19 SDQ[45] SSTL_2 2.5
9 INOUT AH20 SDQ[40] SSTL_2 2.5
10 INOUT AH16 SDQ[32] SSTL_2 2.5
11 INOUT AD18 SDQ[36] SSTL_2 2.5
12 INOUT AG19 SDQ[39] SSTL_2 2.5
13 INOUT AH18 SDQ[38] SSTL_2 2.5
14 INOUT AF19 SDQ[34] SSTL_2 2.5
15 INOUT AE18 SDQ[37] SSTL_2 2.5
16 INOUT AG17 SDQ[33] SSTL_2 2.5
17 INOUT AE20 SDQ[35] SSTL_2 2.5
18 INOUT AG13 SDQ[26] SSTL_2 2.5
19 INOUT AF14 SDQ[27] SSTL_2 2.5
20 INOUT AF13 SDQ[30] SSTL_2 2.5
21 INOUT AH13 SDQ[31] SSTL_2 2.5
Testability
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Intel
®
852GM/852GMV Chipset GMCH Datasheet
161
22
INOUT AD12 SDQ[29] SSTL_2 2.5
23 INOUT AH10 SDQ[24] SSTL_2 2.5
24 INOUT AH11 SDQ[25] SSTL_2 2.5
25 INOUT AG11 SDQ[28] SSTL_2 2.5
26 INOUT AF10 SDQ[22] SSTL_2 2.5
27 INOUT AE11 SDQ[23] SSTL_2 2.5
28 INOUT AG10 SDQ[19] SSTL_2 2.5
29 INOUT AF8 SDQ[16] SSTL_2 2.5
30 INOUT AH9 SDQ[18] SSTL_2 2.5
31 INOUT AD9 SDQ[21] SSTL_2 2.5
32 INOUT AH7 SDQ[20] SSTL_2 2.5
33 INOUT AG8 SDQ[17] SSTL_2 2.5
34 INOUT AF7 SDQ[14] SSTL_2 2.5
35 INOUT AG7 SDQ[10] SSTL_2 2.5
36 INOUT AE8 SDQ[11] SSTL_2 2.5
37 INOUT AH6 SDQ[15] SSTL_2 2.5
38 INOUT AF5 SDQ[12] SSTL_2 2.5
39 INOUT AD6 SDQ[8] SSTL_2 2.5
40 INOUT AH4 SDQ[13] SSTL_2 2.5
41 INOUT AG5 SDQ[9] SSTL_2 2.5
42 INOUT AH2 SDQ[3] SSTL_2 2.5
43 INOUT AF4 SDQ[2] SSTL_2 2.5
44 INOUT AG4 SDQ[6] SSTL_2 2.5
45 INOUT AH3 SDQ[7] SSTL_2 2.5
46 INOUT AF2 SDQ[0] SSTL_2 2.5
47 INOUT AD3 SDQ[4] SSTL_2 2.5
48 INOUT AE3 SDQ[1] SSTL_2 2.5
49 INOUT AE2 SDQ[5] SSTL_2 2.5
Testability
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Intel
®
852GM/852GMV Chipset GMCH Data sheet
7.4.1. VCC/VSS Voltage Groups
Table 34. Voltage Levels and Ball Out for Voltage Groups
Name Voltage Level Ball out
VCC 1.2 H14,J15,N14,N16,P13,P15,P17,R14,R16,T13,T15,
T17,U14,U16,W21,AA15,AA17,AA19
VCCADAC 1.5 A9,B9
VCCDVO 1.5 E1,E4,E6,H7,J1,J4,J8,K9,L8,M4,M8,M9,N1,N8,P9,R8
VCCASM 1.2 AD1,AF1
VCCDLVDS 1.5 B14,B15,G13,J13
VCCGPIO 3.3 A3,A4
VCCHL 1.2 U6,U8,V1,V7,V9,W5,W8,Y1
VCCQSM 2.5 AJ6,AJ8
VCCSM 2.5 Y4,Y7,Y9,AA6,AA8,AA11,AA13,AB3,AB6,AB8,AB10,
AB12,AB14,AB16,AB18,AB20,AB22,AC1,AC29,AF3,
AF6,AF9,AF12,AF15,AF18,AF21,AF24,AF27,AF29,
AG1,AG29,AJ5,AJ9,AJ13,AJ17,AJ21,AJ25
VCCTXLVDS 2.5 A12,B10,D10,F9
VTTHF 1.5 A22,A24,H29,M29,V29
VTTLF 1.5 A18,A20,A26,F29,G15,H16,H18,H20,H22,J19,K29,L21,
M22,N21,P22,R21,T22,U21,V22,Y29,AB29
VSS 0 A13,A17,A19,A21,A23,A25,A27,B5,B24,C1,C7,C10,C22,C29,
D4,D11,D13,D15,D17,D19,D21,D23,D25,D28,E7,E9,E28,E29,
F11,F13,F16,F18,F20,F22,F24,F27,G1,G4,G7,G26,G29,H8,H11,
H13,H15,H17,H19,H21,H24,J7,J10,J12,J14,J16,J18,J20,J22,J26,
J29,K4,K8,K24,L1,L6,L9,L22,L26,L29,M7,M21,M24,N4,N9,N13,
N15,N17,N22,N26,N29,P8,P14,P16,P21,P24,R2,R7,R9,R13,R15,
R17,R22,R26,T4,T8,T9,T14,T16,T21,T24,U1,U5,U9,U13,U15,
U17,U22,U26,U29,V8,V21,V24,W4,W9,W22,W26,W29,Y5,Y6,
Y8,Y21,AA1,AA4,AA7,AA10,AA12,AA14,AA16,AA18,AA20,
AA21,AA23,AA24,AA25,AA29,AB9,AB11,AB13,AB15,AB17,
AB19,AB21,AB26,AC4,AC8,AC11,AC14,AC17,AC20,AC23,
AC27,AC28,AE1,AE4,AE7,AE10,AE13,AE16,AE19,AE22,AE25,
AE28,AG3,AG6,AG9,AG12,AG15,AG18,AG21,AG24,AG27,AJ1,
AJ3,AJ7,AJ10,AJ11,AJ12,AJ18,AJ20,AJ23,AJ26,AJ27
Intel 852GM/852GMV GMCH Strap Pins
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Intel
®
852GM/852GMV Chipset GMCH Datasheet
163
8. Intel 852GM/852GMV GMCH Strap
Pins
8.1. Strapping Configuration
Table 35. Strapping Signals and Configuration
Pin Name Strap Des c ription Configuration I/F Type Buffer Type
HSYNC XOR Chain Test Low = Normal Ops (Default)
High = XOR Test On
GPIO OUT
VSYNC ALL Z Test Low = Normal Ops (Default)
High = AllZ Test On
GPIO OUT
LCLKCTLB
VTT Voltage Select High = Mobile Intel Pentium 4
Processor–M/ Mobile Intel
Celeron processor/Intel
Celeron M processor/Intel
Celeron D processor on 90 nm
process and in the 478-pin
package
GPIO OUT
DVODETECT *DVO Select (If
DVODETECT=0 during
Reset, ADDID[7:0] is
latched to the ADDID
Register)
Low = DVO (Default)
High = Reserved
DVO BI
GST[1] * Clock Config: Bit_1
GST[0] * Clock Config: Bit_0
Please refer to Device #0
Function #3 (HPLLCC
Register) for proper GST[1:0]
settings
DVO Out:
0) Before
CPURST#, there
is internal pull-
down
1) Just out of
CPURST#:
These pins are
Hi-Z
2) C3: these
pins are Hi-Z
3) S1-M: these
pins are Hi-Z
4) Internal GFX
D1/D3: these
pins are Hi-Z
5) S3: these pins
are Power down
6) S4/S5: these
pins are Power
down
* External pull-ups/downs will be required on the board to enable the non-default state of the straps.
Intel 852GM/852GMV GMCH Stra p Pins
R
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Intel
®
852GM/852GMV Chipset GMCH Data sheet
NOTE:
All strap signals are sampled with respect to the leading edge of the Intel 852GM/852GMV GMCH PWROK In
signal.
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Ballout and P ackage Information
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Intel
®
852GM/852GMV Chipset GMCH Datasheet
165
9. Ballout and Package Information
Figure 11. Intel 852GM/852GMV GMCH Ballout Diagram (Top View)
292827262524232221201918171615141312111098765432
AJ NC NC VSS VSS VCCSM SMVREF
_0 VSS SMVSWI
NGL VCCSM VSS SMVSWI
NGH VSS VCCSM VCCSM VSS VSS VSS VCCSM VCCQS
MVSS VCCQS
MVCCSM NC VSS NC
AH NC SDM[7] SDQS[7] SDQ[56] SDQ[51] SDQS[6] SDQ[49] SDQ[43] SDQ[46] SDQ[40] SDQ[45] SDQ[38] SDQS[4] SDQ[32] SDM[8] SDQ[68] SDQ[31] SDM[3] SDQ[25] SDQ[24] SDQ[18] SDQS[2] SDQ[20] SDQ[15] SDQS[1] SDQ[13] SDQ[7] SDQ[3]
AG VCCSM SDQ[58] VSS SDQ[60] SDQ[55] VSS SDQ[52] SDQ[47] VSS SDQ[41] SDQ[39] VSS SDQ[33] SDQ[67] VSS SDQ[64] SDQ[26] VSS SDQ[28] SDQ[19] VSS SDQ[17] SDQ[10] VSS SDQ[9] SDQ[6] VSS SDQS[0]
AF VCCSM SDQ[59] VCCSM SDQ[61] SDQ[54] VCCSM SDQ[53] SDQ[42] VCCSM SDQ[44] SDQ[34] VCCSM SDQ[71] SDQ[70] VCCSM SDQ[27] SDQ[30] VCCSM SMAB[4] SDQ[22] VCCSM SDQ[16] SDQ[14] VCCSM SDQ[12] SDQ[2] VCCSM SDQ[0]
AE BCLK VSS SDQ[62] SDQ[57] VSS SDQ[50] SDQ[48] VSS SDQS[5] SDQ[35] VSS SDQ[37] SDQ[66] VSS SDQ[69] SDQ[65] VSS SDQS[3] SDQ[23] VSS SDM[2] SDQ[11] VSS SDM[1] SDM[0] VSS SDQ[1] SDQ[5]
AD BCLK# RSTIN# SDQ[63] SCS[1]# SWE# SDM[6] SCS[0]# SBA[0] SDM[5] SBA[1] SDM[4] SDQ[36] SMA[3] SMAB[1] SDQS[8] SMA[1] SMA[2] SDQ[29] SMA[4] SMAB[5] SDQ[21] SMA[6] SMA[7] SDQ[8] SMA[11] SCK[2]# SDQ[4] SCK[3]#
AC VCCSM VSS VSS SCK[1] SCS[3]# SCAS# VSS SCS[2]# SRAS# VSS SMA[10] SMA[0] VSS RCVENI
N#
RCVEN
OUT VSS SMA[5] SMAB[2] VSS SCKE[3] SCKE[2] VSS SCKE[0] SMA[8] SMA[9] VSS SCK[2] SCK[3]
AB VTTLF HA[31]# HA[29]# VSS SCK[1]# SCK[4]# SCK[4] VCCSM VSS VCCSM VSS VCCSM VSS VCCSM VSS VCCSM VSS VCCSM VSS VCCSM VSS VCCSM SCKE[1] VCCSM SMA[12] SCK[5]# VCCSM SCK[0]
AA VSS HA[27]# HA[22]# HADSTB
[1]# VSS VSS VSS DPWR# VSS VSS VCC VSS VCC VSS VCC VSS VCCSM VSS VCCSM VSS NC VCCSM VSS VCCSM RSVD VSS SCK[5] SCK[0]#
YVTTLF
HCCVR
E
FHA[26]# HA[30]# HA[21]# HA[17]# DPSLP# HAVREF VSS VCCSM VSS VCCSM VSS VSS VCCSM GCLKIN VCCAG
P
LL
W VSS HA[28]# HA[25]# VSS HA[20]# HA[23]# HA[24]# VSS VCC VSS VCCHL HL[7] HL[5] VCCHL VSS HLSTB HL[4]
V VTTHF HA[11]# HA[14]# HA[16]# HA[18]# VSS HA[19]# VTTLF VSS VCCHL VSS VCCHL HL[6] HL[9] HL[10] HL[3] HLSTB#
U VSS HA[10]# HA[12]# VSS HA[15]# HA[8]# HA[7]# VSS VTTLF VSS VCC VSS VCC VSS VSS VCCHL HL[0] VCCHL VSS HL[1] HL[2] PSW ING
T HA[5]# HA[13]# HADSTB
[0]# HA[4]# VSS HREQ[4]
#VTTLF VSS VCC VSS VCC VSS VCC VSS VSS MDDCD
ATA RSVD RSVD VSS HL[8] HLRCO
MP
RHREQ[0]
#HA[6]# VSS HREQ[3]
#HA[9]# HREQ[2]
#VSS VTTLF VSS VCC VSS VCC VSS
VSS VCCDV
OVSS RSVD RSVD RSVD RSVD VSS
P BPRI# HLOCK# RS[1]# HREQ[1]
#VSS HA[3]# VTTLF VSS VCC VSS VCC VSS VCC VCCDV
OVSS MDDCC
LK RSVD RSVD RSVD RSVD RSVD
N VSS HITM# HIT# VSS BNR# DRDY# RS[0]# VSS VTTLF VSS VCC VSS VCC VSS VSS VCCDV
O
MDVICL
K
MI2CDA
TA RSVD VSS RSVD RSVD
M VTTHF DEFER# RS[2]# DBSY# HTRDY# VSS BREQ0# VTTLF VSS VCCDV
O
VCCDV
OVSS MDVIDA
TA RSVD VCCDV
O
DVOBC
CLKINT RSVD
L VSS ADS# HD[6]# VSS HD[8]# HD[3]# HD[7]# VSS VTTLF VSS VCCDV
O
DVODET
ECT VSS DVOCV
S
YNC RSVD DVOCBL
ANK# RSVD
KVTTLF
HYSWIN
G
HDSTBP
[0]# HD[13]# HD[2]# VSS HD[11]# HD[0]# HDVREF
[0]
VCCDV
OVSS MI2CCL
K
DVOCH
SYNC
DVOCD[
0] VSS DVOCD[
2]
DVOCD[
3]
JVSS
HDSTBN
[0]# HD[4]# VSS DINV[0]# HD[9]# HD[14]# VSS HDVREF
[1] VSS VTTLF VSS HDVREF
[2] VSS VCC VSS VCCDLV
DS VSS PWROK VSS VSYNC VCCDV
OVSS DVOCD[
4]
DVOCD[
5]
VCCDV
O
DVOCC
L
K
DVOCC
L
K#
H VTTHF HYRCO
MP HD[1]# HD[15]# HD[10]# VSS HD[19]# VTTLF VSS VTTLF VSS VTTLF VSS VTTLF VSS VCC VSS IYBM[0] VSS HSYNC LCLKCT
LA VSS VCCDV
O
DVOCD[
10]
DVOCFL
DSTL
DVOCD[
9]
DVOCD[
8]
DVOCD[
6]
G VSS HD[5]# HD[12]# VSS HD[21]# HD[24]# HD[30]# HD[27]# HD[33]# HD[40]# DINV[3]# HD[48]# HD[51]# HD[58]# VTTLF IYAM[0] VCCDLV
DS IYBP[0] IYBM[3] IYBP[3] DDCAD
A
TA
PANELB
KLTCTL VSS
A
DDID[6]
A
DDID[4] VSS DVOCD[
11]
DVOBCI
NTR#
F VTTLF HD[22]# VSS HD[17]# HD[16]# VSS HD[44]# VSS HD[45]# VSS HD[53]# VSS HD[56]# VSS CPURST
#IYAP[0] VSS RSVD VSS ICLKBP VCCTXL
VDS
PANELB
KLTEN
A
GPBUS
Y#
A
DDID[7]
A
DDID[1]
A
DDID[5] RSVD RSVD
E VSS VSS HD[20]# HD[29]# DINV[1]# HD[38]# HD[41]# HDSTBN
[2]#
HDSTBP
[2]# HD[50]# HD[49]# HDSTBP
[3]# HD[61]# HD[59]# IYAM[1] IYAP[1] ICLKAP IYBM[1] IYBP[1] ICLKBM VSS REFSET VSS VCCDV
O
A
DDID[0] VCCDV
O
A
DDID[2]
A
DDID[3]
DVCCAHP
LL VSS HD[23]# HDSTBP
[1]# VSS HD[39]# VSS HD[36]# VSS HD[52]# VSS HDSTBN
[3]# VSS HD[62]# VSS ICLKAM VSS RSVD VSS VCCTXL
VDS BLUE# GREEN# RSVD EXTTS_
0DPMS VSS RSVD RSVD
C VSS HD[25]# HDSTBN
[1]# HD[28]# HD[37]# HD[34]# HD[35]# VSS HD[47]# HD[46]# HD[54]# HD[63]# HD[55]# HD[60]# IYAM[2] IYAP[2] IYAM[3] IYBM[2] IYBP[2] VSS BLUE GREEN VSS LCLKCT
LB
DDCPD
A
TA GST[0] GST[1] RSVD
B NC HD[31]# HD[18]# HD[26]# DINV[2]# VSS HD[43]# HD[42]# HD[32]# HXRCO
MP HD[57]# HXSWIN
G
DREFSS
CLK
VCCADP
LLB
VCCDLV
DS
VCCDLV
DS IYAP[3] RSVD VSSALV
DS
VCCTXL
VDS
VCCAD
A
C
VSSADA
C
DREFCL
K
DDCACL
KVSS DDCPCL
KRSVD RSVD
A NC NC VSS VTTLF VSS VTTHF VSS VTTHF VSS VTTLF VSS VTTLF VSS VSS VCCTXL
VDS
VCCALV
DS LIBG VCCAD
A
CRED# RED VCCADP
LLA
PANELV
DDEN
VCCGPI
O
VCCGPI
ONC
292827262524232221201918171615141312111098765432
Ballout and Package Information
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Intel
®
852GM Chipset GMCH Datasheet
Table 36. Ballout Table
Row Column Signal Name
E 5 ADDID[0]
F 5 ADDID[1]
E 3 ADDID[2]
E 2 ADDID[3]
G 5 ADDID[4]
F 4 ADDID[5]
G 6 ADDID[6]
F 6 ADDID[7]
L 28 ADS#
F 7 AGPBUSY#
AE 29 BCLK
AD 29 BCLK#
C 9 BLUE
D 9 BLUE#
N 25 BNR#
P 28 BPRI#
M 23 BREQ0#
F 15 CPURST#
M 26 DBSY#
B 6 DDCACLK
G 9 DDCADATA
B 4 DDCPCLK
C 5 DDCPDATA
M 28 DEFER#
J 25 DINV[0]#
E 25 DINV[1]#
B 25 DINV[2]#
G 19 DINV[3]#
D 5 DPMS
Y 23 DPSLP#
N 24 DRDY#
B 7 DREFCLK
B 17 DREFSSCLK
L 2 DVOBBLANK#
Row Column Signal Name
M 3 DVOBCCLKINT
G 2 DVOBCINTR#
P 3 RSVD
P 4 RSVD
R 3 RSVD
R 5 RSVD
M 1 RSVD
M 5 RSVD
R 6 RSVD
R 4 RSVD
P 6 RSVD
P 5 RSVD
N 5 RSVD
P 2 RSVD
N 2 RSVD
N 3 RSVD
M 2 RSVD
T 6 RSVD
T 5 RSVD
L 7 DVODETECT
D 1 DVORCOMP
D 6 EXTTS_0
Y 3 GCLKIN
C 8 GREEN
D 8 GREEN#
F 1 GVREF
U 28 HA[10]#
V 28 HA[11]#
U 27 HA[12]#
T 27 HA[13]#
V 27 HA[14]#
U 25 HA[15]#
V 26 HA[16]#
Y 24 HA[17]#
V 25 HA[18]#
Row Column Signal Name
V 23 HA[19]#
W 25 HA[20]#
Y 25 HA[21]#
AA 27 HA[22]#
W 24 HA[23]#
W 23 HA[24]#
W 27 HA[25]#
Y 27 HA[26]#
AA 28 HA[27]#
W 28 HA[28]#
AB 27 HA[29]#
P 23 HA[3]#
Y 26 HA[30]#
AB 28 HA[31]#
T 25 HA[4]#
T 28 HA[5]#
R 27 HA[6]#
U 23 HA[7]#
U 24 HA[8]#
R 24 HA[9]#
T 26 HADSTB[0]#
AA 26 HADSTB[1]#
Y 22 HAVREF
Y 28 HCCVREF
K 22 HD[0]#
H 27 HD[1]#
H 25 HD[10]#
K 23 HD[11]#
G 27 HD[12]#
K 26 HD[13]#
J 23 HD[14]#
H 26 HD[15]#
F 25 HD[16]#
F 26 HD[17]#
B 27 HD[18]#
H 23 HD[19]#
Ballout and P ackage Information
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®
852GM/852GMV Chipset GMCH Datasheet
167
Row Column Signal Name
K 25 HD[2]#
E 27 HD[20]#
G 25 HD[21]#
F 28 HD[22]#
D 27 HD[23]#
G 24 HD[24]#
C 28 HD[25]#
B 26 HD[26]#
G 22 HD[27]#
C 26 HD[28]#
E 26 HD[29]#
L 24 HD[3]#
G 23 HD[30]#
B 28 HD[31]#
B 21 HD[32]#
G 21 HD[33]#
C 24 HD[34]#
C 23 HD[35]#
D 22 HD[36]#
C 25 HD[37]#
E 24 HD[38]#
D 24 HD[39]#
J 27 HD[4]#
G 20 HD[40]#
E 23 HD[41]#
B 22 HD[42]#
B 23 HD[43]#
F 23 HD[44]#
F 21 HD[45]#
C 20 HD[46]#
C 21 HD[47]#
G 18 HD[48]#
E 19 HD[49]#
G 28 HD[5]#
E 20 HD[50]#
Row Column Signal Name
G 17 HD[51]#
D 20 HD[52]#
F 19 HD[53]#
C 19 HD[54]#
C 17 HD[55]#
F 17 HD[56]#
B 19 HD[57]#
G 16 HD[58]#
E 16 HD[59]#
L 27 HD[6]#
C 16 HD[60]#
E 17 HD[61]#
D 16 HD[62]#
C 18 HD[63]#
L 23 HD[7]#
L 25 HD[8]#
J 24 HD[9]#
J 28 HDSTBN[0]#
C 27 HDSTBN[1]#
E 22 HDSTBN[2]#
D 18 HDSTBN[3]#
K 27 HDSTBP[0]#
D 26 HDSTBP[1]#
E 21 HDSTBP[2]#
E 18 HDSTBP[3]#
K 21 HDVREF[0]
J 21 HDVREF[1]
J 17 HDVREF[2]
N 27 HIT#
N 28 HITM#
U 7 HL[0]
U 4 HL[1]
V 4 HL[10]
U 3 HL[2]
V 3 HL[3]
Row Column Signal Name
W 2 HL[4]
W 6 HL[5]
V 6 HL[6]
W 7 HL[7]
T 3 HL[8]
V 5 HL[9]
P 27 HLOCK#
T 2 HLRCOMP
W 3 HLSTB
V 2 HLSTB#
W 1 HLVREF
R 28 HREQ[0]#
P 25 HREQ[1]#
R 23 HREQ[2]#
R 25 HREQ[3]#
T 23 HREQ[4]#
H 10 HSYNC
M 25 HTRDY#
B 20 HXRCOMP
B 18 HXSWING
H 28 HYRCOMP
K 28 HYSWING
D 14 ICLKAM
E 13 ICLKAP
E 10 ICLKBM
F 10 ICLKBP
G 14 IYAM[0]
E 15 IYAM[1]
C 15 IYAM[2]
C 13 IYAM[3]
F 14 IYAP[0]
E 14 IYAP[1]
C 14 IYAP[2]
B 13 IYAP[3]
H 12 IYBM[0]
Ballout and Package Information
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Intel
®
852GM/852GMV Chipset GMCH Data sheet
Row Column Signal Name
E 12 IYBM[1]
C 12 IYBM[2]
G 11 IYBM[3]
G 12 IYBP[0]
E 11 IYBP[1]
C 11 IYBP[2]
G 10 IYBP[3]
H 9 LCLKCTLA
C 6 LCLKCTLB
A 10 LIBG
P 7 MDDCCLK
T 7 MDDCDATA
N 7 MDVICLK
M 6 MDVIDATA
K 7 MI2CCLK
N 6 MI2CDATA
AJ 29 NC
AH 29 NC
B 29 NC
A 29 NC
AJ 28 NC
A 28 NC
AA 9 NC
AJ 4 NC
AJ 2 NC
A 2 NC
AH 1 NC
B 1 NC
G 8 PANELBKLTCTL
F 8 PANELBKLTEN
A 5 PANELVDDEN
U 2 PSWING
J 11 PWROK
AC 16 RCVENIN#
AC 15 RCVENOUT
A 7 RED
Row Column Signal Name
A 8 RED#
E 8 REFSET
N 23 RS[0]#
P 26 RS[1]#
M 27 RS[2]#
AD 28 RSTIN#
AA 22 DPWR#
L 3 DVOCBLANK#
J 3 DVOCCLK
J 2 DVOCCLK#
K 5 DVOCD[0]
K 1 DVOCD[1]
H 6 DVOCD[10]
G 3 DVOCD[11]
K 3 DVOCD[2]
K 2 DVOCD[3]
J 6 DVOCD[4]
J 5 DVOCD[5]
H 2 DVOCD[6]
H 1 DVOCD[7]
H 3 DVOCD[8]
H 4 DVOCD[9]
H 5 DVOCFLDSTL
K 6 DVOCHSYNC
L 5 DVOCVSYNC
F 12 RSVD
D 12 RSVD
B 12 RSVD
AA 5 RSVD
L 4 RSVD
C 4 GST[0]
F 3 RSVD
D 3 RSVD
C 3 GST[1]
B 3 RSVD
F 2 RSVD
Row Column Signal Name
D 2 RSVD
C 2 RSVD
B 2 RSVD
D 7 RSVD
AD 22 SBA[0]
AD 20 SBA[1]
AC 24 SCAS#
AB 2 SCK[0]
AA 2 SCK[0]#
AC 26 SCK[1]
AB 25 SCK[1]#
AC 3 SCK[2]
AD 4 SCK[2]#
AC 2 SCK[3]
AD 2 SCK[3]#
AB 23 SCK[4]
AB 24 SCK[4]#
AA 3 SCK[5]
AB 4 SCK[5]#
AC 7 SCKE[0]
AB 7 SCKE[1]
AC 9 SCKE[2]
AC 10 SCKE[3]
AD 23 SCS[0]#
AD 26 SCS[1]#
AC 22 SCS[2]#
AC 25 SCS[3]#
AE 5 SDM[0]
AE 6 SDM[1]
AE 9 SDM[2]
AH 12 SDM[3]
AD 19 SDM[4]
AD 21 SDM[5]
AD 24 SDM[6]
AH 28 SDM[7]
AH 15 SDM[8]
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Row Column Signal Name
AF 2 SDQ[0]
AE 3 SDQ[1]
AG 7 SDQ[10]
AE 8 SDQ[11]
AF 5 SDQ[12]
AH 4 SDQ[13]
AF 7 SDQ[14]
AH 6 SDQ[15]
AF 8 SDQ[16]
AG 8 SDQ[17]
AH 9 SDQ[18]
AG 10 SDQ[19]
AF 4 SDQ[2]
AH 7 SDQ[20]
AD 9 SDQ[21]
AF 10 SDQ[22]
AE 11 SDQ[23]
AH 10 SDQ[24]
AH 11 SDQ[25]
AG 13 SDQ[26]
AF 14 SDQ[27]
AG 11 SDQ[28]
AD 12 SDQ[29]
AH 2 SDQ[3]
AF 13 SDQ[30]
AH 13 SDQ[31]
AH 16 SDQ[32]
AG 17 SDQ[33]
AF 19 SDQ[34]
AE 20 SDQ[35]
AD 18 SDQ[36]
AE 18 SDQ[37]
AH 18 SDQ[38]
AG 19 SDQ[39]
AD 3 SDQ[4]
Row Column Signal Name
AH 20 SDQ[40]
AG 20 SDQ[41]
AF 22 SDQ[42]
AH 22 SDQ[43]
AF 20 SDQ[44]
AH 19 SDQ[45]
AH 21 SDQ[46]
AG 22 SDQ[47]
AE 23 SDQ[48]
AH 23 SDQ[49]
AE 2 SDQ[5]
AE 24 SDQ[50]
AH 25 SDQ[51]
AG 23 SDQ[52]
AF 23 SDQ[53]
AF 25 SDQ[54]
AG 25 SDQ[55]
AH 26 SDQ[56]
AE 26 SDQ[57]
AG 28 SDQ[58]
AF 28 SDQ[59]
AG 4 SDQ[6]
AG 26 SDQ[60]
AF 26 SDQ[61]
AE 27 SDQ[62]
AD 27 SDQ[63]
AG 14 SDQ[64]
AE 14 SDQ[65]
AE 17 SDQ[66]
AG 16 SDQ[67]
AH 14 SDQ[68]
AE 15 SDQ[69]
AH 3 SDQ[7]
AF 16 SDQ[70]
AF 17 SDQ[71]
Row Column Signal Name
AD 6 SDQ[8]
AG 5 SDQ[9]
AG 2 SDQS[0]
AH 5 SDQS[1]
AH 8 SDQS[2]
AE 12 SDQS[3]
AH 17 SDQS[4]
AE 21 SDQS[5]
AH 24 SDQS[6]
AH 27 SDQS[7]
AD 15 SDQS[8]
AC 18 SMA[0]
AD 14 SMA[1]
AC 19 SMA[10]
AD 5 SMA[11]
AB 5 SMA[12]
AD 13 SMA[2]
AD 17 SMA[3]
AD 11 SMA[4]
AC 13 SMA[5]
AD 8 SMA[6]
AD 7 SMA[7]
AC 6 SMA[8]
AC 5 SMA[9]
AD 16 SMAB[1]
AC 12 SMAB[2]
AF 11 SMAB[4]
AD 10 SMAB[5]
AB 1 SMRCOMP
AJ 24 SMVREF_0
AJ 19 SMVSWINGH
AJ 22 SMVSWINGL
AC 21 SRAS#
AD 25 SWE#
W 21 VCC
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Row Column Signal Name
AA 19 VCC
AA 17 VCC
T 17 VCC
P 17 VCC
U 16 VCC
R 16 VCC
N 16 VCC
AA 15 VCC
T 15 VCC
P 15 VCC
J 15 VCC
U 14 VCC
R 14 VCC
N 14 VCC
H 14 VCC
T 13 VCC
P 13 VCC
B 9 VCCADAC
A 9 VCCADAC
A 6 VCCADPLLA
B 16 VCCADPLLB
Y 2 VCCAGPLL
D 29 VCCAHPLL
A 11 VCCALVDS
AF 1 VCCASM
AD 1 VCCASM
B 15 VCCDLVDS
B 14 VCCDLVDS
J 13 VCCDLVDS
G 13 VCCDLVDS
P 9 VCCDVO
M 9 VCCDVO
K 9 VCCDVO
R 8 VCCDVO
N 8 VCCDVO
M 8 VCCDVO
Row Column Signal Name
L 8 VCCDVO
J 8 VCCDVO
H 7 VCCDVO
E 6 VCCDVO
M 4 VCCDVO
J 4 VCCDVO
E 4 VCCDVO
N 1 VCCDVO
J 1 VCCDVO
E 1 VCCDVO
A 4 VCCGPIO
A 3 VCCGPIO
V 9 VCCHL
W 8 VCCHL
U 8 VCCHL
V 7 VCCHL
U 6 VCCHL
W 5 VCCHL
Y 1 VCCHL
V 1 VCCHL
AJ 8 VCCQSM
AJ 6 VCCQSM
AG 29 VCCSM
AF 29 VCCSM
AC 29 VCCSM
AF 27 VCCSM
AJ 25 VCCSM
AF 24 VCCSM
AB 22 VCCSM
AJ 21 VCCSM
AF 21 VCCSM
AB 20 VCCSM
AF 18 VCCSM
AB 18 VCCSM
AJ 17 VCCSM
AB 16 VCCSM
Row Column Signal Name
AF 15 VCCSM
AB 14 VCCSM
AJ 13 VCCSM
AA 13 VCCSM
AF 12 VCCSM
AB 12 VCCSM
AA 11 VCCSM
AB 10 VCCSM
AJ 9 VCCSM
AF 9 VCCSM
Y 9 VCCSM
AB 8 VCCSM
AA 8 VCCSM
Y 7 VCCSM
AF 6 VCCSM
AB 6 VCCSM
AA 6 VCCSM
AJ 5 VCCSM
Y 4 VCCSM
AF 3 VCCSM
AB 3 VCCSM
AG 1 VCCSM
AC 1 VCCSM
A 12 VCCTXLVDS
D 10 VCCTXLVDS
B 10 VCCTXLVDS
F 9 VCCTXLVDS
AA 29 VSS
W 29 VSS
U 29 VSS
N 29 VSS
L 29 VSS
J 29 VSS
G 29 VSS
E 29 VSS
C 29 VSS
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Row Column Signal Name
AE 28 VSS
AC 28 VSS
E 28 VSS
D 28 VSS
AJ 27 VSS
AG 27 VSS
AC 27 VSS
F 27 VSS
A 27 VSS
AJ 26 VSS
AB 26 VSS
W 26 VSS
U 26 VSS
R 26 VSS
N 26 VSS
L 26 VSS
J 26 VSS
G 26 VSS
AE 25 VSS
AA 25 VSS
D 25 VSS
A 25 VSS
AG 24 VSS
AA 24 VSS
V 24 VSS
T 24 VSS
P 24 VSS
M 24 VSS
K 24 VSS
H 24 VSS
F 24 VSS
B 24 VSS
AJ 23 VSS
AC 23 VSS
AA 23 VSS
Row Column Signal Name
D 23 VSS
A 23 VSS
AE 22 VSS
W 22 VSS
U 22 VSS
R 22 VSS
N 22 VSS
L 22 VSS
J 22 VSS
F 22 VSS
C 22 VSS
AG 21 VSS
AB 21 VSS
AA 21 VSS
Y 21 VSS
V 21 VSS
T 21 VSS
P 21 VSS
M 21 VSS
H 21 VSS
D 21 VSS
A 21 VSS
AJ 20 VSS
AC 20 VSS
AA 20 VSS
J 20 VSS
F 20 VSS
AE 19 VSS
AB 19 VSS
H 19 VSS
D 19 VSS
A 19 VSS
AJ 18 VSS
AG 18 VSS
AA 18 VSS
Row Column Signal Name
J 18 VSS
F 18 VSS
AC 17 VSS
AB 17 VSS
U 17 VSS
R 17 VSS
N 17 VSS
H 17 VSS
D 17 VSS
A 17 VSS
AE 16 VSS
AA 16 VSS
T 16 VSS
P 16 VSS
J 16 VSS
F 16 VSS
AG 15 VSS
AB 15 VSS
U 15 VSS
R 15 VSS
N 15 VSS
H 15 VSS
D 15 VSS
AC 14 VSS
AA 14 VSS
T 14 VSS
P 14 VSS
J 14 VSS
AE 13 VSS
AB 13 VSS
U 13 VSS
R 13 VSS
N 13 VSS
H 13 VSS
F 13 VSS
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Row Column Signal Name
D 13 VSS
A 13 VSS
AJ 12 VSS
AG 12 VSS
AA 12 VSS
J 12 VSS
AJ 11 VSS
AC 11 VSS
AB 11 VSS
H 11 VSS
F 11 VSS
D 11 VSS
AJ 10 VSS
AE 10 VSS
AA 10 VSS
J 10 VSS
C 10 VSS
AG 9 VSS
AB 9 VSS
W 9 VSS
U 9 VSS
T 9 VSS
R 9 VSS
N 9 VSS
L 9 VSS
E 9 VSS
AC 8 VSS
Y 8 VSS
V 8 VSS
T 8 VSS
P 8 VSS
K 8 VSS
H 8 VSS
Row Column Signal Name
AJ 7 VSS
AE 7 VSS
AA 7 VSS
R 7 VSS
M 7 VSS
J 7 VSS
G 7 VSS
E 7 VSS
C 7 VSS
AG 6 VSS
Y 6 VSS
L 6 VSS
Y 5 VSS
U 5 VSS
B 5 VSS
AE 4 VSS
AC 4 VSS
AA 4 VSS
W 4 VSS
T 4 VSS
N 4 VSS
K 4 VSS
G 4 VSS
D 4 VSS
AJ 3 VSS
AG 3 VSS
R 2 VSS
AJ 1 VSS
AE 1 VSS
AA 1 VSS
U 1 VSS
L 1 VSS
G 1 VSS
Row Column Signal Name
C 1 VSS
B 8 VSSADAC
B 11 VSSALVDS
J 9 VSYNC
V 29 VTTHF
M 29 VTTHF
H 29 VTTHF
A 24 VTTHF
A 22 VTTHF
AB 29 VTTLF
Y 29 VTTLF
K 29 VTTLF
F 29 VTTLF
A 26 VTTLF
V 22 VTTLF
T 22 VTTLF
P 22 VTTLF
M 22 VTTLF
H 22 VTTLF
U 21 VTTLF
R 21 VTTLF
N 21 VTTLF
L 21 VTTLF
H 20 VTTLF
A 20 VTTLF
J 19 VTTLF
H 18 VTTLF
A 18 VTTLF
H 16 VTTLF
G 15 VTTLF
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9.1. Package Mechanical Information
The following figures provide detail on the package information and dimensions of the Intel
852GM/852GMV GMCH. The Intel 852GM/852GMV GMCH comes in a Micro-FCBGA package,
which is similar to the mobile processors. The package consists of a silicon die mounted face down on
an organic substrate populated with solder balls on the bottom side. Capacitors may be placed in the
area surrounding the die. Because the die-side capacitors are electrically conductive, and only slightly
shorter than the die heigh t, care should be taken to avoid contacting the capacitors with electrically
conductive materials. Doing so may short the capacitors and possibly damage the device or render it
inactive.
The use of an insulating mate rial between the capacitors and any thermal so lution should be considered
to prevent capacitor shorting. An exclusion, or keepout area, surrounds the die and capacitors, and
identifies the contact area for the pack age. Care should be taken to avoid contact with the pack age inside
this area.
Figure 12. Intel 852GM/852GMV GMCH Micro-FCBGA Package Dimensions (Top View)
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Figure 13. Intel 852GM/852GMV GMCH Micro-FCBGA Package Dimensions (Side View)
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Figure 14. Intel 852GM/852GMV GMCH Micro-FCBGA Package Dimensions (Bottom View)
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