290656-002

R Intel® 810 Chipset: Intel® 82810/82810-DC100 Graphics and Memory Controller Hub (GMCH) Datasheet June 1999 Order Number: 290656-002 Intel 82810/82810-DC100 (GMCH) ® R 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 fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. Intel products are not intended for use in medical, life saving, or life sustaining applications. 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® 810 and Intel® 810-DC100 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. I2C is a 2-wire communications bus/protocol developed by Philips. SMBus is a subset of the I2C bus/protocol and was developed by Intel. Implementations of the I2C 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-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: Intel Corporation or call 1-800-548-4725 *Third-party brands and names are the property of their respective owners. Copyright © Intel Corporation 1998, 1999 2 Datasheet R Intel 82810/82810-DC100 (GMCH) ® Contents 1. Overview..................................................................................................................................... 11 1.1. 1.2. 1.3. 1.4. 1.5. 1.6. 1.7. 1.8. 1.9. 2. The Intel 810 Chipset System ..................................................................................... 11 GMCH Overview............................................................................................................ 14 Host Interface ................................................................................................................ 15 System Memory Interface.............................................................................................. 15 Display Cache Interface (82810-DC100 Only)............................................................... 15 Hub Interface ................................................................................................................. 15 GMCH Graphics Support............................................................................................... 16 1.7.1. Display, Digital Video Out, and LCD/Flat Panel ................................................ 16 System Clocking ............................................................................................................ 17 References .................................................................................................................... 17 ® Signal Description....................................................................................................................... 19 2.1. 2.2. 2.3. 2.4. 2.5. 2.6. 2.7. 2.8. 2.9. 2.10. 2.11. Host Interface Signals.................................................................................................... 20 System Memory Interface Signals ................................................................................. 21 Display Cache Interface Signals (82810-DC100 only)................................................... 22 Hub Interface Signals .................................................................................................... 22 Display Interface Signals ............................................................................................... 23 Digital Video Output Signals/TV-Out Pins ..................................................................... 24 Power Signals ................................................................................................................ 25 Clock Signals ................................................................................................................. 25 Miscellaneous Interface Signals .................................................................................... 26 Power-Up/Reset Strap Options (82810) ........................................................................ 26 Power-Up/Reset Strap Options (82810-DC100)............................................................ 26 3. Configuration Registers .............................................................................................................. 27 3.1. 3.2. Register Nomenclature and Access Attributes .............................................................. 27 PCI Configuration Space Access................................................................................... 28 3.2.1. PCI Bus Configuration Mechanism ................................................................... 28 3.2.2. Logical PCI Bus #0 Configuration Mechanism.................................................. 29 3.2.3. Primary PCI (PCI0) and Downstream Configuration Mechanism ..................... 29 3.2.4. Internal Graphics Device Configuration Mechanism......................................... 29 3.2.5. GMCH Register Introduction ............................................................................. 29 I/O Mapped Registers.................................................................................................... 30 3.3.1. CONFIG_ADDRESSConfiguration Address Register ................................... 30 3.3.2. CONFIG_DATAConfiguration Data Register ................................................ 31 Host-Hub Interface Bridge/DRAM Controller Device Registers (Device 0) ................... 31 3.4.1. VIDVendor Identification Register (Device 0) ................................................ 33 3.4.2. DIDDevice Identification Register (Device 0) ................................................ 33 3.4.3. PCICMDPCI Command Register (Device 0)................................................. 33 3.4.4. PCISTSPCI Status Register (Device 0) ........................................................ 35 3.4.5. RIDRevision Identification Register (Device 0).............................................. 36 3.4.6. SUBCSub-Class Code Register (Device 0) .................................................. 36 3.4.7. BCCBase Class Code Register (Device 0) ................................................... 36 3.4.8. MLTMaster Latency Timer Register (Device 0)............................................. 37 3.4.9. HDRHeader Type Register (Device 0) .......................................................... 37 3 3.3. 3.4. Datasheet Intel 82810/82810-DC100 (GMCH) ® R 3.5. 3.6. 3.7. 3.4.10. SVIDSubsystem Vendor Identification Register (Device 0) .......................... 37 3.4.11. SIDSubsystem Identification Register (Device 0) ......................................... 38 3.4.12. CAPPTRCapabilities Pointer (Device 0) ....................................................... 38 3.4.13. GMCHCFGGMCH Configuration Register (Device 0) .................................. 39 3.4.14. PAMR—Programmable Attributes Register (Device 0) .................................... 40 3.4.15. DRPDRAM Row Population Register (Device 0) .......................................... 41 3.4.16. DRAMTDRAM Timing Register (Device 0) ................................................... 43 3.4.17. FCHCFixed DRAM Hole Control Register (Device 0)................................... 44 3.4.18. SMRAMSystem Management RAM Control Register (Device 0) ................ 45 3.4.19. MISCCMiscellaneous Control Register (Device 0) ....................................... 47 3.4.20. MISCC2Miscellaneous Control 2 Register (Device 0) .................................. 48 3.4.21. BUFF_SC—System Memory Buffer Strength Control Register (Device 0) ...... 49 Graphics Device Registers – (Device 1) ....................................................................... 51 3.5.1. VIDVendor Identification Register (Device 1) ............................................... 52 3.5.2. DIDDevice Identification Register (Device 1)................................................ 52 3.5.3. PCICMDPCI Command Register (Device 1) ................................................ 53 3.5.4. PCISTSPCI Status Register (Device 1) ........................................................ 54 3.5.5. RIDRevision Identification Register (Device 1) ............................................. 55 3.5.6. PI-Programming Interface Register (Device 1) ................................................ 55 3.5.7. SUBC1—Sub-Class Code Register (Device 1) ................................................ 55 3.5.8. BCC1—Base Class Code Register (Device 1)................................................. 56 3.5.9. CLSCache Line Size Register (Device 1) ..................................................... 56 3.5.10. MLTMaster Latency Timer Register (Device 1) ............................................ 56 3.5.11. HDRHeader Type Register (Device 1).......................................................... 57 3.5.12. BISTBuilt In Self Test (BIST) Register (Device 1) ........................................ 57 3.5.13. GMADRGraphics Memory Range Address Register (Device 1) .................. 58 3.5.14. MMADRMemory Mapped Range Address Register (Device 1).................... 59 3.5.15. SVIDSubsystem Vendor Identification Register (Device 1) .......................... 59 3.5.16. SIDSubsystem Identification Register (Device 1) ......................................... 60 3.5.17. ROMADRVideo BIOS ROM Base Address Registers (Device 1)................ 60 3.5.18. CAPPOINTCapabilities Pointer Register (Device 1)..................................... 60 3.5.19. INTRLINEInterrupt Line Register (Device 1)................................................. 61 3.5.20. INTRPINInterrupt Pin Register (Device 1) .................................................... 61 3.5.21. MINGNTMinimum Grant Register (Device 1) ............................................... 61 3.5.22. MAXLATMaximum Latency Register (Device 1) .......................................... 61 3.5.23. PM_CAPIDPower Management Capabilities ID Register (Device 1) ........... 62 3.5.24. PM_CAPPower Management Capabilities Register (Device 1).................... 62 3.5.25. PM_CS—Power Management Control/Status Register (Device 1)................. 63 Display Cache Interface (82810-DC100 Only) .............................................................. 64 3.6.1. DRT—DRAM Row Type ................................................................................... 64 3.6.2. DRAMCL—DRAM Control Low ........................................................................ 65 3.6.3. DRAMCH—DRAM Control High....................................................................... 66 Display Cache Detect and Diagnostic Registers (82810-DC100 Only)........................ 67 3.7.1. GRXGRX Graphics Controller Index Register .............................................. 67 3.7.2. MSRMiscellaneous Output ........................................................................... 68 3.7.3. GR06Miscellaneous Register ....................................................................... 69 3.7.4. GR10Address Mapping................................................................................. 70 3.7.5. GR11Page Selector ...................................................................................... 70 4 Datasheet R Intel 82810/82810-DC100 (GMCH) Functional Description ................................................................................................................ 71 4.1. System Address Map..................................................................................................... 71 4.1.1. Memory Address Ranges.................................................................................. 71 4.1.1.1. Compatibility Area ................................................................................ 72 4.1.1.2. Extended Memory Area........................................................................ 74 4.1.1.3. System Management Mode (SMM) Memory Range ............................ 76 4.1.2. Memory Shadowing .......................................................................................... 76 4.1.3. I/O Address Space ............................................................................................ 77 4.1.4. GMCH Decode Rules and Cross-Bridge Address Mapping ............................. 77 Host Interface ................................................................................................................ 78 4.2.1. Host Bus Device Support .................................................................................. 78 4.2.2. Special Cycles................................................................................................... 81 System Memory DRAM Interface .................................................................................. 82 4.3.1. DRAM Organization and Configuration............................................................. 82 4.3.1.1. Configuration Mechanism For DIMMs.................................................. 83 4.3.1.2. DRAM Register Programming.............................................................. 84 4.3.2. DRAM Address Translation and Decoding ....................................................... 84 4.3.3. DRAM Array Connectivity.................................................................................. 86 4.3.4. SDRAMT Register Programming...................................................................... 86 4.3.5. SDRAM Paging Policy....................................................................................... 87 Intel® Dynamic Video Memory Technology (D.V.M.T.) .................................................. 87 Display Cache Interface (82810-DC100 Only)............................................................... 87 4.5.1. Supported DRAM Types ................................................................................... 88 4.5.2. Memory Configurations ..................................................................................... 88 4.5.3. Address Translation .......................................................................................... 89 4.5.4. Display Cache Interface Timing ........................................................................ 89 Internal Graphics Device ............................................................................................... 90 4.6.1. 3D/2D Instruction Processing ........................................................................... 90 4.6.2. 3D Engine ......................................................................................................... 91 4.6.3. Buffers............................................................................................................... 91 4.6.4. Setup................................................................................................................. 93 4.6.5. Texturing ........................................................................................................... 93 4.6.6. 2D Operation..................................................................................................... 95 4.6.7. Fixed Blitter (BLT) and Stretch Blitter (STRBLT) Engines ................................ 95 4.6.7.1. Fixed BLT Engine................................................................................. 96 4.6.7.2. Arithmetic Stretch BLT Engine ............................................................. 96 4.6.8. Hardware Motion Compensation....................................................................... 96 4.6.9. Hardware Cursor............................................................................................... 97 4.6.10. Overlay Engine.................................................................................................. 97 4.6.11. Display............................................................................................................... 97 4.6.12. Flat Panel Interface / 1.8V TV-Out Interface..................................................... 99 4.6.13. DDC (Display Data Channel) .......................................................................... 100 System Reset for the GMCH ....................................................................................... 101 System Clock Description............................................................................................ 101 Power Management..................................................................................................... 101 4.9.1. Specifications Supported ................................................................................ 101 82810 and 82810-DC100 GMCH Pinout ..................................................................... 103 Package Dimensions ................................................................................................... 109 ® 4. 4.2. 4.3. 4.4. 4.5. 4.6. 4.7. 4.8. 4.9. 5. Pinout and Package Information .............................................................................................. 103 5.1. 5.2. Datasheet 5 Intel 82810/82810-DC100 (GMCH) 6. ® R Testability................................................................................................................................. 111 6.1. 6.2. XOR TREE Testability Algorithm Example ................................................................. 112 6.1.1. Test Pattern Consideration for XOR Chain 7 ................................................. 112 XOR Tree Initialization ................................................................................................ 113 6.2.1. Chain [1:2, 4:7] Initialization............................................................................ 113 6.2.2. Chain 3 Initialization........................................................................................ 113 XOR Chain Pin Assignments ...................................................................................... 114 6.3. 6 Datasheet R Intel 82810/82810-DC100 (GMCH) ® Figures Figure 1. Intel 810 Chipset System Block Diagram With Intel 82810 GMCH and Either ICH or ICH0 ....................................................................................................12 ® Figure 2. Intel 810 Chipset System Block Diagram With Intel 82810-DC100 GMCH and ICH.....................................................................................................................13 Figure 3. GMCH Block Diagram...............................................................................................14 Figure 4. System Memory Address Map ..................................................................................71 Figure 5. Detailed Memory System Address Map ....................................................................72 Figure 6. GMCH Graphics Register Memory Address Space ..................................................75 Figure 7. DRAM Array Sockets (2 DIMM Sockets) ..................................................................86 Figure 8. GMCH Display Cache Interface to 4MB....................................................................88 Figure 9. 3D/2D Pipeline Preprocessor ....................................................................................90 Figure 10. Data Flow for the 3D Pipeline..................................................................................92 Figure 11. GMCH Pinout (Top View-Left Side) ......................................................................104 Figure 12. GMCH Pinout (Top View-Right Side) ....................................................................105 Figure 13. GMCH Package Dimensions (421 BGA) – Top and Side Views ..........................109 Figure 14. GMCH Package Dimensions (421 BGA) – Bottom View ......................................110 Figure 15. XOR Tree Implementation ....................................................................................111 ® Tables Table 1. Power-Up Options (82810).........................................................................................26 Table 2. Power-Up Options (82810-DC100) ............................................................................26 Table 3. GMCH PCI Configuration Space (Device 0) ..............................................................32 Table 4. Programming DRAM Row Population Register Fields ...............................................42 Table 5. GMCH Configuration Space (Device 1) .....................................................................51 Table 6. Memory Map for 03000h–0FFFFh Address Offset Range.........................................64 Table 7. Memory Segments and their Attributes ......................................................................73 Table 8. Summay of Transactions Supported By GMCH.........................................................79 Table 9. Host Responses Supported by the GMCH.................................................................80 Table 10. Special Cycles ..........................................................................................................81 Table 11. Sample Of Possible Mix And Match Options For 4 Row/2 DIMM Configurations ....83 Table 12. Data Bytes on DIMM Used for Programming DRAM Registers ...............................84 Table 13. GMCH DRAM Address Mux Function ......................................................................85 Table 14. Programmable SDRAM Timing Parameters ............................................................86 Table 15. Memory Size for Each Configuration........................................................................88 Table 16. GMCH Local Memory Address Mapping..................................................................89 Table 17. Partial List of Display Modes Supported ..................................................................98 Table 18. Partial List of Flat Panel Modes Supported ..............................................................99 Table 19. Partial List of TV-Out Modes Supported.................................................................100 Table 20. Alphabetical Pin Assignment.................................................................................106 Table 21. GMCH Package Dimensions (421 BGA) ...............................................................110 Table 22. XOR Test Pattern Example....................................................................................112 Table 23. XOR Chain 1 ..........................................................................................................114 Table 24. XOR Chain 2 ..........................................................................................................114 Table 25. XOR Chain 3 ..........................................................................................................115 Table 26. XOR Chain 4 ..........................................................................................................116 Table 27. XOR Chain 5 ..........................................................................................................117 Table 28. XOR Chain 6 ..........................................................................................................118 Table 29. XOR Chain 7 ..........................................................................................................119 Datasheet 7 Intel 82810/82810-DC100 (GMCH) ® R Revision History Rev. -002 Description Editorial changes throughout for clarification Updated Section 4.4, Section 2.6 (CLKOUT[1:0] description), Section 2.5 (IREF description), Added new figure in Sectdion 3.6. -001 Initial Release April 1999 Date June 1999 8 Datasheet R Intel 82810/82810-DC100 (GMCH) ® Intel® 82810 and Intel® 82810-DC100 Product Features ƒ Processor/Host Bus Support ®       Optimized for the Intel CeleronTM processor Supports processor 370-Pin Socket connector Supports 32-Bit System Bus Addressing 4 deep in-order queue; 4 or 1 deep request queue Supports Uni-processor systems only In-order and Dynamic Deferred Transaction Support  66/100MHz System Bus Frequency  AGTL+ I/O Buffer Integrated DRAM Controller ƒ  8 MB to 256 MB using 16Mb/64Mb technology (512 MB using 128Mb technology)  Supports up to 2 double sided DIMM modules  64-bit data interface  100MHz system memory bus frequency  Support for Asymmetrical DRAM addressing only  Support for x8, x16 and x32 DRAM device width  Refresh Mechanism: CBR ONLY supported  Enhanced Open page Arbitration SDRAM paging scheme  Suspend to RAM support ƒ Integrated Graphics Controller  3D Hyper Pipelined Architecture  -Parallel Data Processing (PDP)  -Precise Pixel Interpolation (PPI)  Full 2D H/W Acceleration  Motion Video Acceleration 3D Graphics Visual Enhancements ƒ  Flat & Gouraud Shading  Mip Maps with Bilinear and Anisotropic Filtering  Fogging Atmospheric Effects  Z-Buffering  3D Pipe 2D Clipping  Backface Culling 3D Graphics Texturing Enhancements ƒ  Per Pixel Perspective Correction Texture Mapping  Texture Compositing  Texture Color Keying/Chroma Keying ƒ Digital Video Output  85MHz Flat Panel Monitor Interface Or Digital Video Output for use with a external TV encoder Display ƒ  Integrated 24-bit 230MHz RAMDAC  Gamma Corrected Video  DDC2B Compliant ƒ 2D Graphics  Up to 1600x1200 in 8-bit Color at 85 Hz Refresh  Hardware Accelerated Functions  3 Operand Raster BitBLTs  64x64x3 Color Transparent Cursor ƒ Arithmetic Stretch Blitter Video  H/W Motion Compensation Assistance for S/W MPEG2 Decode  Software DVD at 30fps  Digital Video Out Port  NTSC and PAL TV Out Support  H/W Overlay Engine with Bilinear Filtering  Independent gamma correction, saturation, brightness & contrast for overlay ƒ Integrated Graphics Memory Controller  Intel® D.V.M. Technology ƒ Display Cache Interface (82810-DC100 Only)  32-bit data interface  100 MHz SDRAM interface  Support for 1Mx16, (4 MB Only) Arbitration Scheme and Concurrency ƒ  Centralized Arbitration Model for Optimum Concurrency Support  Concurrent operations of processor and System busses supported via dedicated arbitration and data buffering Data Buffering ƒ  Distributed Data Buffering Model for optimum concurrency  DRAM Write Buffer with read-around-write capability  Dedicated CPU-DRAM, hub interface-DRAM and Graphics-DRAM Read Buffers ƒ Power Management Functions  SMRAM space remapping to A0000h (128 KB)  Optional Extended SMRAM space above 256 MB, additional 512K/1MB TSEG from Top of Memory, cacheable  Stop Clock Grant and Halt special cycle translation from the host to the hub interface  ACPI Compliant power management  APIC Buffer Management  SMI, SCI, and SERR error indication ƒ Supporting I/O Bridge  241 Pin BGA I/O Controller Hub (ICH0/ICH) ƒ Packaging/Power  421 BGA  1.8V core with 3.3V CMOS I/O Datasheet 9 Intel 82810/82810-DC100 (GMCH) GMCH Simplified Block Diagram HA[31:3]# HD[63:0]# ADS# BNR# BPRI# DBSY# DEFER# DRDY# HIT# HITM# HLOCK# HREQ[4:0]# HTRDY# RS[2:0]# CPURST# SMAA[11:0] SMAB[7:4]# SBS[1:0] SMD[63:0] SDQM[7:0] SCS[3:0]# SRAS# SCAS# SWE# SCKE[1:0] VSYNC HSYNC IREF RED GREEN BLUE DDCSCL DDCSDA ® R Display Interface System Bus Interface Digital TV Out LTVCL LTVDA TVCLKIN/INT# CLKOUT[1:0] BLANK# LTVDATA[11:0] TVSYNC TVHSYNC HCLK SCLK LTCLK LOCLK LRCLK DCLKREF HLCLK GLRREFA GTLREFB RESET# HUBREF HL[10:0] HLSTRB HLSTRB# HCOMP System Memory Interface Clock Signals LCS# LDQM[3:0]# LSRAS# LSCAS# LMA[11:0] LWE# LMD[31:0] Display Cache Interface (82810DC100 Only) Misc. Interface Signals Hub Interface Note: The Display Cache Interface is only avaliable on the 82810-DC100. gmch_blk.vsd 10 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 1. Overview The Intel® 810 chipset is a high-integration chipset designed for the basic graphics/multimedia PC platform. The chipset consists of a Graphics and Memory Controller Hub (GMCH) Host Bridge and an I/O Controller Hub (ICH/ICH0) Bridge for the I/O subsystem. The GMCH integrates a system memory DRAM controller that supports a 64-bit 100 MHz DRAM array. The DRAM controller is optimized for maximum efficiency. There are two versions of the GMCH (82810 and 82810-DC100). These two versions are pin compatible. The difference between the two versions is that the 82810DC-100 integrates a Display Cache DRAM controller that supports a 4 MB, 32-bit 100 MHz DRAM array for enhanced 2D and 3D performance. This document describes both versions of the GMCH (82810 and 82810-DC100). An overview of the Intel® 810 chipset is provided in the next section. Note: In this document the term “GMCH” refers to both the 82810 and 82810-DC100, unless otherwise specified. The Intel® 810 and Intel® 810-DC100 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. 1.1. The Intel® 810 Chipset System The Intel® 810 Chipset uses a hub architecture with the GMCH as the host bridge hub and the 82801xx I/O Controller Hub (ICH) as the I/O hub. The ICH is a highly integrated multifunctional I/O Controller Hub that provides the interface to the PCI Bus and integrates many of the functions needed in today’s PC platforms. The GMCH and ICH communicate over a dedicated hub interface. Like the GMCH, there are two versions of the ICH (82801AA: ICH and 82801AB: ICH0). This provides added flexibility in designing cost-effective system solutions. These devices are pin compatible and are in 241-pin packages. The GMCH devices are designed to work with either ICH or ICH0. 82801AA (ICH) / 82801AB (ICH0) functions and capabilities include: • PCI Rev 2.2 compliant with support for 33 MHz PCI operations • ICH0 Supports up to 4 Req/Gnt pairs (PCI Slots); ICH supports up to 6 Req/Gnt pairs (PCI Slots) • Power Management Logic Support • Enhanced DMA Controller, Interrupt Controller & Timer Functions • Integrated IDE controller; ICH0 supports Ultra ATA/33; ICH also supports Ultra ATA/66 • USB host interface with support for 2 USB ports • System Management Bus (SMBus) compatible with most I2C devices • AC’97 2.1 Compliant Link for Audio and Telephony CODECs • Low Pin Count (LPC) interface • Firmware Hub (FWH) interface support • Alert On LAN* (82801AA ICH only) Datasheet 11 Intel 82810/82810-DC100 (GMCH) Figure 1and Figure 2 show block diagrams of typical platforms based on the Intel® 810 Chipset. The GMCH supports processor bus frequencies of 66/100 MHz. Figure 1 shows a system without a display cache. It uses the Intel 82810 GMCH and either the ICH (82801AA) or ICH0 (82801AB). Both ICH0 and ICH provide extensive I/O support. The ICH provides additional support for 6 PCI bus Req/Gnt pairs (instead of 4 for the ICH0), increased IDE capability from Ultra ATA/33 to Ultra ATA/66, and Alert On LAN*. Figure 2 shows a system based on the 82810-DC100 GMCH that includes a display cache. Figure 1. Intel 810 Chipset System Block Diagram With Intel 82810 GMCH and Either ICH or ICH0 Processor System Bus (66/100 MHz) Digital Video Out Encoder Intel® 82810 (GMCH0) TV ® R ® Intel® 810 Chipset 64 Bit / 100 MHz Only System Memory Display - Memory Controller - Graphcs Controller - 3D Engine - 2D Engine - Video Engine PCI Slots (ICH = 6 Req/Gnt pairs) (ICH0 = 4 Req/Gnt pairs) PCI Bus ISA Option LAN Option Audio Codec Modem Codec 2 IDE Ports ICH = Ultra ATA/66 ICH0 = Ultra ATA/33 ICH and ICH0 (I/O Controller Hub) Super I/O AC'97 2 USB Ports USB USB FWH (Firmware Hub) sysblk1.vsd 12 Datasheet R Intel 82810/82810-DC100 (GMCH) ® ® Figure 2. Intel 810 Chipset System Block Diagram With Intel 82810-DC100 GMCH and ICH Processor System Bus (66/100 MHz) Digital Video Out Encoder Intel® 82810-DC100 (GMCH) 64 Bit / 100 MHz Only Intel® 810 Chipset TV System Memory Display Display Cache - Memory Controller - Graphcs Controller - 3D Engine - 2D Engine - Video Engine PCI Slots (ICH=6 Req/Gnt pairs) PCI Bus ISA Option LAN Option Audio Codec Modem Codec (4 MB SDRAM, 100 MHz Only) 2 IDE Ports Ultra ATA/66 ICH (I/O Controller Hub) Super I/O AC'97 2 USB Ports USB USB FWH (Firmware Hub) sysblk2.vsd Datasheet 13 Intel 82810/82810-DC100 (GMCH) ® R 1.2. GMCH Overview Figure 3 is a block diagram of the GMCH illustrating the various interfaces and integrated components of the GMCH chip. The GMCH functions and capabilities include: • Support for a single processor configuration • 64-bit AGTL+ based System Bus Interface at 66 MHz/100 MHz • 32-bit Host Address Support • 64-bit System Memory Interface with optimized support for SDRAM at 100 MHz • Integrated 2D & 3D Graphics Engines • Integrated H/W Motion Compensation Engine • Integrated 230 MHz DAC • Integrated Digital Video Out Port • 4 MB Display Cache (82810-DC100 only) Figure 3. GMCH Block Diagram System Bus Interface Buffer Display En g ine HW Motion Comp 3D En g ine 3D En g ine 2D En g ine Memory Interface Display Cache Memory (82810-DC100 only) System Memory Analo g Display Out DAC Overla y HW Cursor Di g ital Video Out DDC I2C Stretch BLT En g B LT En g Di g ital Video Out Port Buffer Hub Interface gmch_blk2.vsd 14 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 1.3. Host Interface The host interface of the GMCH is optimized to support the Intel® CeleronTM processor. The GMCH implements the host address, control, and data bus interfaces within a single device. The GMCH supports a 4-deep in-order queue (i.e., supports pipelining of up to 4 outstanding transaction requests on the host bus) . Host bus addresses are decoded by the GMCH for accesses to system memory, PCI memory and PCI I/O (via hub interface), PCI configuration space and Graphics memory. The GMCH takes advantage of the pipelined addressing capability of the processor to improve the overall system performance. The GMCH supports the 370-pin socket (PGA370). This is a zero insertion force (ZIF) socket that a processor in the PPGA package uses to interface with a system board. 1.4. System Memory Interface The GMCH integrates a system memory DRAM controller that supports a 64-bit 100 MHz DRAM array. The DRAM type supported is industry standard Synchronous DRAM (SDRAM). The DRAM controller interface is fully configurable through a set of control registers. Complete descriptions of these registers are given in the Configuration Register Description Section. The GMCH supports industry standard 64-bit wide DIMM modules with SDRAM devices. The twelve multiplexed address lines, SMAA[11:0], along with the two bank select lines, SBS[1:0], allow the GMCH to support 2M, 4M, 8M, and 16M x64 DIMMs. Only asymmetric addressing is supported. The GMCH has four SCS# lines, enabling the support of up to four 64-bit rows of DRAM. The GMCH targets SDRAM with CL2 and CL3 and supports both single and double-sided DIMMs. Additionally, the GMCH also provides a seven deep refresh queue. The GMCH can be configured to keep multiple pages open within the memory array, pages can be kept open in any one row of memory. SCKE[1:0] is used in configurations requiring powerdown mode for the SDRAM. 1.5. Display Cache Interface (82810-DC100 Only) The 82810-DC100 GMCH supports a Display Cache DRAM controller with a 32-bit 100 MHz DRAM array. The DRAM type supported is industry standard Synchronous DRAM (SDRAM) like that of the system memory. The local memory DRAM controller interface is fully configurable through a set of control registers. Complete descriptions of these registers are given in the Register Description Section. 1.6. Hub Interface The hub interface is a private interconnect between the GMCH and the ICH. Datasheet 15 Intel 82810/82810-DC100 (GMCH) ® R 1.7. GMCH Graphics Support The Graphics and Memory Controller Hub (GMCH) includes a highly integrated graphics accelerator. Its architecture consists of dedicated multi-media engines executing in parallel to deliver high performance 3D, 2D and motion compensation video capabilities. The 3D and 2D engines are managed by a 3D/2D pipeline preprocessor allowing a sustained flow of graphics data to be rendered and displayed. The deeply pipelined 3D accelerator engine provides 3D graphics quality and performance via per-pixel 3D rendering and parallel data paths that allow each pipeline stage to simultaneously operate on different primitives or portions of the same primitive. The GMCH graphics accelerator engine supports perspective-correct texture mapping, bilinear and anisotropic Mip-Mapping, Gouraud shading, alphablending, fogging and Z-buffering. A rich set of 3D instructions permit these features to be independently enabled or disabled. For the 82810-DC100, a Display Cache (DC) can be used for Z-buffers (Textures and display buffer are located in system memory). If the display cache is not used, the Z-buffer is located in system memory. The GMCH integrated graphics accelerator’s 2D capabilities include BLT and arithmetic STRBLT engines, a hardware cursor and an extensive set of 2D registers and instructions. The high performance 64-bit BitBLT engine provides hardware acceleration for many common Windows operations. In addition to its 2D/3D capabilities, the GMCH integrated graphics accelerator also supports full MPEG-2 motion compensation for software-assisted DVD video playback, a VESA DDC2B compliant display interface and a digital video out port that may support (via an external video encoder) NTSC and PAL broadcast standards. 1.7.1. Display, Digital Video Out, and LCD/Flat Panel The GMCH provides interfaces to a standard progressive scan monitor, TV-Out device, and LCD/Flat Panel transmitter. • The GMCH directly drives a standard progressive scan monitor up to a resolution of 1600x1200. • The GMCH provides a Digital Video Out interface to connect an external device to drive an autodetection of 1024x768 non-scalar DDP digital Flat Panel with appropriate EDID 1.x data. The interface has 1.8V signaling to allow it to operate at higher frequencies. This interface can also connect to a 1.8V TV-Out encoder. 16 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 1.8. System Clocking The GMCH has a new type of clocking architecture. It has integrated SDRAM buffers that always run at 100 MHz, regardless of system bus frequency. The system bus frequency is selectable between 66 MHz and 100 MHz. The GMCH uses a copy of the USB clock as the DOT Clock input for the graphics pixel clock PLL. 1.9. References • • • • • Intel® 810 Chipset Design Guide (Order Number 290657) PC ’99: Contact www.microsoft.com/hwdev AGTL+ I/O Specification: Contained in the Pentium® II Processor Databook PCI Local bus Specification 2.2: Contact www.pcisig.com Intel® 82801AA (ICH) and Intel® 82801AB (ICH0) I/O Controller Hub Datasheet (Order Number 290655) Datasheet 17 Intel 82810/82810-DC100 (GMCH) ® R 18 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 2. Signal Description This section provides a detailed description of the GMCH signals. The signals are arranged in functional groups according to their associated interface. The states of all of the signals during reset are provided in the System Reset section. The “#” symbol at the end of a signal name indicates that the active, or asserted state occurs when the signal is at a low voltage level. When “#” is not present after the signal name the signal is asserted when at the high voltage level. The following notations are used to describe the signal type: I O I/OD I/O Input pin Output pin Input / Open Drain Output pin. This pin requires a pullup to the VCC of the processor core Bi-directional Input/Output pin The signal description also includes the type of buffer used for the particular signal: AGTL+ CMOS LVTTL 1.8V Analog Open Drain AGTL+ interface signal. Refer to the AGTL+ I/O Specification for complete details The CMOS buffers are Low Voltage TTL compatible signals. These are 3.3V only. Low Voltage TTL compatible signals. There are 3.3V only. 1.8V signals for the digital video interface Analog CRT Signals Note that the processor address and data bus signals (Host Interface) are logically inverted signals (i.e., the actual values are inverted versions of what appears on the processor 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 conventions. A 0 indicates an active level (low voltage) if the signal is followed by a “#” symbol and a 1 indicates an active level (high voltage) if the signal has no “#” suffix. Datasheet 19 Intel 82810/82810-DC100 (GMCH) ® R 2.1. Host Interface Signals Signal Name CPURST# Type O AGTL+ Description CPU Reset. The GMCH asserts CPURST# while RESET# (PCIRST# from ICH) is asserted and for approximately 1ms after RESET# is deasserted. The GMCH also pulses CPURST# for approximately 1ms when requested via a hub interface special cycle. The CPURST# allows the processor to begin execution in a known state. Host Address Bus: HA[31:3]# connect to the processor address bus. During processor cycles, HA[31:3]# are inputs. The GMCH drives HA[31:3]# during snoop cycles on behalf of Primary PCI. Note that the address bus is inverted on the processor bus. Host Data: These signals are connected to the processor data bus. Note that the data signals are inverted on the processor bus. Address Strobe: The processor bus owner asserts ADS# to indicate the first of two cycles of a request phase. Block Next Request: Used to block the current request bus owner from issuing a new request. This signal is used to dynamically control the processor bus pipeline depth. Priority Agent Bus Request: The GMCH is the only Priority Agent on the processor bus. It asserts this signal to obtain the ownership of the address bus. This signal has priority over symmetric bus requests and causes the current symmetric owner to stop issuing new transactions, unless the HLOCK# signal was asserted. Data Bus Busy: Used by the data bus owner to hold the data bus for transfers requiring more than one cycle. Defer: The GMCH generates a deferred response as defined by the rules of the GMCH dynamic defer policy. The GMCH also uses the DEFER# signal to indicate a processor retry response. Data Ready: Asserted for each cycle that data is transferred. 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. 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. HITM# is also driven in conjunction with HIT# to extend the snoop window. Host Lock: All processor bus cycles sampled with the assertion of HLOCK# and ADS#, until the negation of HLOCK# must be atomic (i.e., no hub interface or GMCH graphics snoopable access to DRAM is allowed when HLOCK# is asserted by the processor). Host Request Command: Asserted during both clocks of request phase. In the first clock, the signals define the transaction type to a level of detail that is sufficient to begin a snoop request. In the second clock, the signals carry additional information to define the complete transaction type. The transactions supported by the GMCH are defined in the Host Interface section of this document. HA[31:3]# I/O AGTL+ HD[63:0]# ADS# BNR# I/O AGTL+ I/O AGTL+ I/O AGTL+ O AGTL+ BPRI# DBSY# DEFER# I/O AGTL+ O AGTL+ I/O AGTL+ I/O AGTL+ I/O AGTL+ I AGTL+ DRDY# HIT# HITM# HLOCK# HREQ[4:0]# I/O AGTL+ 20 Datasheet R Intel 82810/82810-DC100 (GMCH) Signal Name HTRDY# RS[2:0]# Type I/O AGTL+ I/O AGTL+ Description Host Target Ready: Indicates that the target of the processor transaction is able to enter the data transfer phase. Response Signals: Indicates type of response as shown below: RS[2:0] 000 001 010 011 100 101 110 111 Response type Idle state Retry response Deferred response Reserved (not driven by the GMCH) Hard Failure (not driven by the GMCH) No data response Implicit Writeback Normal data response ® 2.2. System Memory Interface Signals Signal Name SMAA[11:0] SMAB[7:4]# SBS[1:0] SMD[63:0] SDQM[7:0] SCS[3:0]# Type O CMOS I/O CMOS O CMOS O CMOS O CMOS O CMOS O CMOS O CMOS Description Memory Address: SMAA[11:0] and SMAB[7:4]# are used to provide the multiplexed row and column address to DRAM. SBS[1:0] provide the Bank Select. Memory Data: These signals are used to interface to the DRAM data bus. Input/Output Data Mask: These pins act as synchronized output enables during read cycles and as a byte enables during write cycles. Chip Select: For the memory row configured with SDRAM, these pins perform the function of selecting the particular SDRAM components during the active state. SDRAM Row Address Strobe: These signals drive the SDRAM array directly without any external buffers. SDRAM Column Address Strobe: These signals drive the SDRAM array directly without any external buffers. Write Enable Signal: SWE# is asserted during writes to DRAM. System Memory Clock Enable: SCKE SDRAM Clock Enable is used to signal a self-refresh or power-down command to an SDRAM array when entering system suspend. SRAS# SCAS# SWE# SCKE[1:0] Datasheet 21 Intel 82810/82810-DC100 (GMCH) ® R 2.3. Display Cache Interface Signals (82810-DC100 only) Signal Name LCS# LDQM[3:0] Type O CMOS O CMOS O CMOS Description Chip Select: For the memory row configured with SDRAM, these pins perform the function of selecting the particular SDRAM components during the active state. Input/Output Data Mask: These pins control the memory array and act as synchronized output enables during read cycles and as a byte enables during write cycles. SDRAM Row Address Strobe: The LSRAS# signal is used to generate SDRAM Command encoded on LSRAS#/LSCAS#/LWE# signals. When LRAS# is sampled active at the rising edge of the SDRAM clock, the row address is latched into the SDRAMs. SDRAM Column Address Strobe: The LSCAS# signal is used to generate SDRAM Command encoded on LSRAS#/LSCAS#/LWE# signals. When LSCAS# is sampled active at the rising edge of the SDRAM clock, the column address is latched into the SDRAMs. Memory Address: LMA[11:0] is used to provide the multiplexed row and column address to DRAM. Write Enable Signal: LWE# is asserted during writes to DRAM. Memory Data: These signals are used to interface to the DRAM data bus of DRAM array. LSRAS# LSCAS# O CMOS LMA[11:0] LWE# LMD[31:0] O CMOS O CMOS I/O CMOS 2.4. Hub Interface Signals Signal Name HL[10:0] HLSTRB HLSTRB# HUBREF HCOMP Type I/O I/O I/O I Ref I/O Description Hub Interface Signals: Signals used for the hub interface. Packet Strobe: One of two differential strobe signals used to transmit or receive packet data. Packet Strobe Compliment: One of two differential strobe signals used to transmit or receive packet data. HUB reference: Sets the differential voltage reference for the hub interface. Hub Compensation Pad: Used to calibrate the hub interface buffers. 22 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 2.5. Display Interface Signals Signal Name VSYNC HSYNC IWASTE IREF RED Type O 3.3V O 3.3V I Ref I Ref O Analog O Analog O Analog I/OD CMOS Description CRT Vertical Synchronization: This signal is used as the vertical sync (polarity is programmable) or “ Vsync Interval”. CRT Horizontal Synchronization: This signal is used as the horizontal sync (polarity is programmable) or “ Hsync Interval”. Waste Reference: This signal must be tied to ground. Set pointer resistor for the internal color palette DAC: A 174 ohm 1% resistor is recommended CRT Analog video output from the internal color palette DAC: The DAC is designed for a 37.5 ohms equivalent load on each pin (e.g. 75 ohms resistor on the board, in parallel with the 75 ohms CRT load) CRT Analog video output from the internal color palette DAC: The DAC is designed for a 37.5 ohms equivalent load on each pin (e.g. 75 ohms resistor on the board, in parallel with the 75 ohms CRT load) CRT Analog video output from the internal color palette DAC: The DAC is designed for a 37.5 ohms equivalent load on each pin (e.g., 75 ohms resistor on the board, in parallel with the 75 ohms CRT load) CRT Monitor DDC Interface Clock: (Also referred to as VESATM “Display Data Channel”, also referred to as the “Monitor Plug-n-Play” interface.) For DDC1, DDCSCL and DDCSDA provides a unidirectional channel for Extended Display ID. For DDC2, DDCSCL and DDCSDA it can be used to establish a bi-directional 2 channel based on I C protocol. The host can request Extended Display ID or Video Display Interface information over the DDC2 channel. CRT Monitor DDC Interface Data: GREEN BLUE DDCSCL DDCSDA I/OD CMOS Datasheet 23 Intel 82810/82810-DC100 (GMCH) ® R 2.6. Digital Video Output Signals/TV-Out Pins Signal Name TVCLKIN/INT# Type I 1.8V Description Low Voltage TV Clock In (TV-Out Mode): In 1.8V TV-Out usage, the TVCLKIN pin functions as a pixel clock input to the GMCH from the TV encoder. The TVCLKIN frequency ranges from 20 MHz to 40 MHz depending on the mode (e.g., NTSC or PAL) and the overscan compensation values in the TV Encoder. CLKIN has a worse case duty cycle of 60%/40% coming in to the GMCH. Flat Panel Interrupt (LCD Mode): In Flat Panel usage, the INT# pin is asserted to cause an interrupt (typically, to indicate a hot plug or unplug of a flat panel). In Flat Panel usage, this pin is connected internally to a pullup resistor. CLKOUT[1:0] BLANK# O 1.8V O 1.8V LCD/TV Port Clock Out: These pins provide a differential pair reference clock that can run up to 85 MHz. Flicker Blank or Border Period Indication: BLANK# is a programmable output pin driven by the graphics control. 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. LCD/TV Data: These signals are used to interface to the LCD/TV-out data bus. Vertical Sync: VSYNC signal for the LTV interface. The active polarity of the signal is programmable. Horizontal Sync: HSYNC signal for the LTV interface. The active polarity of the signal is programmable. LCD/TV Clock: Clock pin for 2-wire interface. LCD/TV Data: Data pin for 2-wire interface. LTVDATA[11:0] TVVSYNC TVHSYNC LTVCL LTVDA O 1.8V O 1.8V O 1.8V I/OD CMOS I/OD CMOS 24 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 2.7. Power Signals Signal Name V_1.8 V_3.3 VSUS_3.3 VCCDA VCCDACA1 VCCHA VCCBA VCCDACA2 VSSDA VSSDACA VSS Type Power Power Power Power Power Power Power Power Power Power Power Core Power (1.8V) I/O Buffer Power (3.3V) System Memory Buffer Power (Separate 3.3V power plane for power down modes) Display Power Signal (Connect to an isolated 1.8V plane with VCCDACA1 and VCCDACA2) Display Power Signal (Connect to an isolated 1.8V plane with VCCDA and VCCDACA2) Isolated 1.8V Power Isolated 1.8V Power Display Power Signal (Connect to an isolated 1.8V plane with VCCDA and VCCDACA1) Display Ground Signal Display Ground Signal Core Ground Description 2.8. Clock Signals Signal Name HCLK SCLK LTCLK LOCLK LRCLK DCLKREF HLCLK Type I CMOS I CMOS O CMOS O CMOS I CMOS I CMOS I CMOS Description Host Clock Input: Clock used on the host interface. Externally generated 66/100 MHz clock. System Memory Clock: Clock used on the output buffers of system memory. Externally generated 100 MHz clock. Transmit Clock: LTCLK is an internally generated local memory clock used to clock the input buffers of the SDRAM devices of the display cache. Output Clock: LOCLK is an internally generated clock used to drive LRCLK. Receive Clock: LRCLK is a display cache clock used to clock the input buffers of the GMCH. Display Interface Clock: DCLKREF is a 48 MHz clock generated by an external clock synthesizer to the GMCH. Hub Interface Clock: 66 MHz hub interface clock generated by an external clock synthesizer. Datasheet 25 Intel 82810/82810-DC100 (GMCH) ® R 2.9. Miscellaneous Interface Signals Signal Name GTLREFA GTLREFB RESET# Type I Ref I Ref I Description AGTL Reference Voltage: Reference signal to the Host Interface. AGTL Reference Voltage: Reference signal to the Host Interface. Global Reset: Driven by the ICH/ICH0 when PCIRST# is active. 2.10. Power-Up/Reset Strap Options (82810) Table 1 lists power-up options that are loaded into the 82810 GMCH during cold reset. Table 1. Power-Up Options (82810) Pin Location F22 F21 G23 G22 Description XOR Chain Test Select: Set to 0 for normal operation. It must be set to 1 to enter XOR tree mode during reset. This pin must remain 1 during the entire XOR tree test. ALL Z Select: If the pin is set to 1, all signals are tri-stated during reset. For normal operation, this pin should be set to 0. Host Frequency Select: If this pin is set to 0 during reset, the host bus frequency is 66 Mhz. If the pin is set to 1, the host bus frequency is 100 MHz. In-Order Queue Depth Status: If set to 0 during reset, the IOQD is 4. If set to 1, the IOQD is 1. 2.11. Power-Up/Reset Strap Options (82810-DC100) Table 2 list power-up options that are loaded into the 82810-DC100 GMCH during cold reset. Table 2. Power-Up Options (82810-DC100) Signal LMD[31] LMD[30] LMD[29] LMD[28] Description XOR Chain Test Select: LMD[31] is set to 0 for normal operation. It must be set to 1 to enter XOR tree mode during reset. This signal must remain 1 during the entire XOR tree test. ALL Z select: If LMD[30] is set to 1, all signals are tri-stated during reset. For normal operation, LMD[30] should be set to 0 Host Frequency Select: If LMD[29] is set to 0 during reset, the host bus frequency is 66 MHz. If LMD[29] is set to 1, the host bus frequency is 100 MHz. In-Order Queue Depth Status: The value on LMD[28] sampled at the rising edge of CPURST# reflects if the IOQD is set to 1 or 4. If LMD[28] is set to 0, the IOQD is 4. If LMD[28] is set to 1, the IOQD is 1. 26 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3. Configuration Registers This section describes the following register sets: • PCI Configuration Registers (82810 and 82810-DC100). The GMCH contains PCI configuration registers for Device 0 (Host-hub interface Bridge/DRAM Controller) and Device 1 (GMCH internal graphics device). • Display Cache Interface Registers (82810-DC100 only). This register set is used for configuration of the Display Cache (DC) interface. The registers are located in memory space. The memory space addresses listed are offsets from the base memory address programmed into the MMADR register (Device 1, PCI configuration offset 14h). • Display Cache Detect and Diagnostic Registers (82810-DC100 only). This register set can be used for DC memory detection and testing. These registers are accessed via either I/O space or memory space. The memory space addresses listed are offsets from the base memory address programmed into the MMADR register (Device 1, PCI configuration offset 14h). Note that the GMCH also contains an extensive set of registers and instructions for controlling its graphics operations. Intel graphics drivers provide the software interface at this architectural level. The register/instruction interface is transparent at the Application Programmers Interface (API) level and thus, beyond the scope of this document. 3.1. Register Nomenclature and Access Attributes RO R/W R/WC R/WO Reserved Bits Read Only. If a register is read only, writes to this register have no effect. Read/Write. A register with this attribute can be read and written 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. Read/Write Once. A register bit with this attribute can be written to only once after power up. After the first write, the bit becomes read only. Some of the GMCH registers described in this section contain reserved bits. These bits are labeled "Reserved” or “Intel 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, write operation for the configuration address register. In addition to reserved bits within a register, the GMCH contains address locations in the configuration space of the Host-hub interface Bridge/DRAM Controller and the internal graphics device entities that are marked either "Reserved” or Intel Reserved”. When a “Reserved” register location is read, a random value can be returned. (“Reserved” registers can be 8-, 16-, or 32-bit in size). Registers that are marked as “Reserved” must not be modified by system software. Writes to “Reserved” registers may cause system failure. 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 options. 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 DRAM configurations, operating parameters and optional system features that are applicable, and to program the GMCH registers accordingly. Reserved Registers Default Value Upon Reset Datasheet 27 Intel 82810/82810-DC100 (GMCH) ® R 3.2. PCI Configuration Space Access The GMCH and the ICH are physically connected via the hub interface. From a configuration standpoint, the hub interface connecting the GMCH and the ICH is logically PCI bus #0. All devices internal to the GMCH and ICH appear to be on PCI bus #0. The system primary PCI expansion bus is physically attached to the ICH and, from a configuration standpoint, appears as a hierarchical PCI bus behind a PCI-to-PCI bridge. The primary PCI expansion bus connected to the ICH has a programmable PCI Bus number. Note: Even though the primary PCI bus is referred to as PCI0 in this document it is not PCI bus #0 from a configuration standpoint. The GMCH contains two PCI devices within a single physical component. The configuration registers for both Device 0 and 1 are mapped as devices residing on PCI bus #0. • Device 0: Host-hub interface Bridge/DRAM Controller. Logically this appears as a PCI device residing on PCI bus #0. Physically Device 0 contains the PCI registers, DRAM registers, and other GMCH specific registers. • Device 1: GMCH internal graphics device. These registers contain the PCI registers for the GMCH internal graphics device. Note that a physical PCI bus #0 does not exist. The hub interface and the internal devices in the GMCH and ICH logically constitute PCI Bus #0 to configuration software. 3.2.1. PCI Bus Configuration Mechanism The PCI Bus defines a slot based "configuration space" that allows each device to contain up to 8 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 processor. Configuration space is supported by a mapping mechanism implemented within the GMCH. The PCI 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 and CONFIG_DATA Register. 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 window into the four bytes of configuration space specified by the contents of CONFIG_ADDRESS. Any read or write to CONFIG_DATA results in the GMCH translating the CONFIG_ADDRESS into the appropriate configuration cycle. The GMCH is responsible for translating and routing the processor I/O accesses to the CONFIG_ADDRESS and CONFIG_DATA registers to internal GMCH configuration registers, the internal graphic device, or the hub interface. 28 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.2.2. Logical 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. • Device #0: The Host-hub interface Bridge/DRAM Controller entity within the GMCH is hardwired as Device #0 on PCI Bus #0. • Device #1: The internal graphics device entity within the GMCH is hardwired as Device #1 on PCI Bus #0. Configuration cycles to one of the GMCH internal devices are confined to the GMCH and not sent over the hub interface. Note: Accesses to devices #2 to #31 on PCI Bus #0 are forwarded over the hub interface. 3.2.3. Primary PCI (PCI0) and Downstream Configuration Mechanism If the Bus Number in the CONFIG_ADDRESS is non-zero the GMCH generates a configuration cycle over the hub interface. The ICH 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 (PCI0), or a downstream PCI bus. 3.2.4. Internal Graphics Device Configuration Mechanism From the chipset configuration perspective the internal graphics device is seen as a PCI device (device #1) on PCI Bus #0. Configuration cycles that target device #1 on PCI Bus #0 are claimed by the internal graphics device and are not forwarded via hub interface to the ICH. 3.2.5. GMCH Register Introduction The GMCH contains two sets of software accessible registers, accessed via the Host I/O address space: • Control registers I/O mapped into the host I/O space. These registers control access to PCI configuration space (see section entitled I/O Mapped Registers) • Internal configuration registers residing within the GMCH are partitioned into two logical device register sets (“logical” since they reside within a single physical device). The first register set is dedicated to Host-hub interface Bridge/DRAM Controller functionality (controls PCI0 such as DRAM configuration, other chip-set operating parameters and optional features). The second register block is dedicated to the internal graphics device in the GMCH. The GMCH supports PCI configuration space accesses using the mechanism denoted as Configuration Mechanism #1 in the PCI specification. The GMCH internal registers (both I/O Mapped and Configuration registers) are accessible by the host. The registers can be accessed as Byte, Word (16-bit), or DWord (32-bit) quantities, with the exception of CONFIG_ADDRESS that can only be accessed as a DWord. All multi-byte numeric fields use "littleendian" ordering (i.e., lower addresses contain the least significant parts of the field). Datasheet 29 Intel 82810/82810-DC100 (GMCH) ® R 3.3. I/O Mapped Registers GMCH contains two registers that reside in the processor I/O address space − the Configuration Address (CONFIG_ADDRESS) Register and the Configuration Data (CONFIG_DATA) Register. The Configuration Address Register enables/disables the configuration space and determines what portion of configuration space is visible through the Configuration Data window. 3.3.1. CONFIG_ADDRESSConfiguration Address Register I/O Address: Default Value: Access: Size: 0CF8h Accessed as a DWord 00000000h Read/Write 32 bits CONFIG_ADDRESS is a 32 bit register accessed only when referenced as a Dword. A Byte or Word reference will "pass through" the Configuration Address Register and the hub interface onto the PCI #0 bus as an I/O cycle. The CONFIG_ADDRESS register contains the Bus Number, Device Number, Function Number, and Register Number for which a subsequent configuration access is intended. 31 Config En 30 Reserved (0) 24 23 Bus Number 16 15 Device Number 11 10 Function Number 8 7 Register Number 2 1 Reserved 0 Bit 31 Configuration Enable (CFGE). Descriptions 1 = Enable accesses to PCI configuration space 0 = Disable accesses to PCI configuration space 30:24 23:16 Reserved (These bits are read only and have a value of 0). Bus Number. When the Bus Number is programmed to 00h the target of the Configuration Cycle is either a hub interface agent GMCH or the ICH. The Configuration Cycle is forwarded to the hub interface if the Bus Number is programmed to 00h and the GMCH is not the target. 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/DRAM Controller entity and Device Number 1 for the internal graphics device. Therefore, when the Bus Number =0 and the Device Number=0 or 1 the internal GMCH devices are selected. For Bus Numbers resulting in the hub interface configuration cycles the GMCH propagates the Device Number field as HA[15:11]. 10:8 Function Number. This field is mapped to HA[10:8] during the 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 it’s two internal Devices if the function number is not equal to 0. 30 Datasheet R Intel 82810/82810-DC100 (GMCH) Bit 7:2 Descriptions 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 HA[7:2] during the hub interface Configuration cycles. Reserved. ® 1:0 3.3.2. CONFIG_DATAConfiguration Data Register I/O Address: Default Value: Access: Size: 0CFCh 00000000h Read/Write 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. Bit 31:0 Descriptions Configuration Data Window (CDW). If bit 31 of CONFIG_ADDRESS is 1, any I/O reference that falls in the CONFIG_DATA I/O space will be mapped to configuration space using the contents of CONFIG_ADDRESS. 3.4. Host-Hub Interface Bridge/DRAM Controller Device Registers (Device 0) Table 3 shows the GMCH configuration space for device #0. Datasheet 31 Intel 82810/82810-DC100 (GMCH) Table 3. GMCH PCI Configuration Space (Device 0) Address Offset 00–01h 02–03h 04–05h 06–07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh 10–2Bh 2C–2Dh 2E–2Fh 30–33h 34h 35–4Fh 50h 51h 52h 53h 54–57h 58h 58–6Fh 70h 72–73h 74–7Fh 80h 81–91h 92–93h 94–FFh Register Symbol VID DID PCICMD PCISTS RID  SUBC BCC  MLT HDR   SVID SID  CAPPTR  GMCHCFG PAM DRP DRAMT  FDHC  SMRAM MISSC  MISSC2  BSC  Register Name Vendor Identification Device Identification PCI Command Register PCI Status Register Revision Identification Reserved Sub-Class Code Base Class Code Reserved Master Latency Timer Header Type Reserved Reserved Subsystem Vendor Identification Subsystem Identification Reserved Capabilities Pointer Reserved GMCH Configuration Programmable Attributes DRAM Row Population DRAM Timing Register Reserved Fixed DRAM Hole Control Reserved System Management RAM Control Miscellaneous Control Reserved Miscellaneous Control 2 Reserved Buffer Strength Control Reserved Default Value 8086h 7120h/7122h 0006h 0080h 00h 00h 00h 06h 00h 00h 00h   0000h 0000h  00h  60h 00h 00h 08h  00h  00h 0000h  00h  FFFFh  Access RO RO R/W RO, R/WC RO  RO RO  RO RO   R/WO R/WO  RO  R/W R/W R/W R/W  R/W  R/W R/W  R/W  R/W  ® R 32 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.4.1. VIDVendor Identification Register (Device 0) Address Offset: Default Value: Attribute: Size: 00–01h 8086h Read Only 16 bits The VID Register contains the vendor identification number. This 16-bit register combined with the Device Identification Register uniquely identify any PCI device. Writes to this register have no effect. Bit 15:0 Description Vendor Identification Number. This is a 16-bit value assigned to Intel. Intel VID = 8086h. 3.4.2. DIDDevice Identification Register (Device 0) Address Offset: Default Value: Attribute: Size: 02–03h 82810 = 7120h 82810-DC100 = 7122h Read Only 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 15:0 Description Device Identification Number. This is a 16 bit value assigned to the GMCH Host-hub interface Bridge/DRAM Controller Device #0. 3.4.3. PCICMDPCI Command Register (Device 0) Address Offset: Default: Access: Size 04–05h 0006h Read/Write 16 bits This 16-bit register provides basic control over the GMCH PCI0 (i.e., Hub-Interface) interface’s ability to respond to Hub Interface cycles. Datasheet 33 Intel 82810/82810-DC100 (GMCH) ® R 15 Reserved (0) 10 9 FB2B (Not Impl) 8 SERR En 7 Addr/Data Stepping (Not Impl) 6 Parity Error En (Not Impl) 5 VGA Pal Sn (Not Impl) 4 Mem WR & Inval En (Not Impl) 3 Special Cycle En (Not Impl) 2 Bus Master En (Not Impl) 1 Mem AccEn (Not Impl) 0 I/O AccEn (Not Impl) Bit 15:10 9 8 Reserved. Descriptions Fast Back-to-Back. (Not implemented; hardwired to 0). Writes to this bit position have no effect SERR Enable (SERRE). This bit is a global enable bit for Device #0 SERR messaging. The GMCH does not have an SERR# signal. The GMCH communicates the SERR condition by sending an SERR message to the ICH. If this bit is set to a 1, the GMCH is enabled to generate SERR messages over the hub interface for specific Device #0 error conditions (Note: the only SERR condition for the GMCH is Received Target Abort, therefore there are no other SERR enable bits in the GMCH ). If SERRE is reset to 0, then the SERR message is not generated by the GMCH for Device #0. NOTE: This bit only controls SERR messaging for the Device #0. 7 6 5 4 3 2 1 0 Address/Data Stepping. (Not implemented; hardwired to 0). Writes to this bit position have no effect. Parity Error Enable (PERRE). (Not implemented; hardwired to 0). Writes to this bit position have no effect. VGA Palette Snoop. (Not implemented, hardwired to 0). Writes to this bit position have no effect Memory Write and Invalidate Enable. (Not implemented; hardwired to 0). Writes to this bit position have no effect Special Cycle Enable. (Not implemented; hardwired to 0). Writes to this bit position have no effect Bus Master Enable (BME). (Not implemented: hardwired to 1). GMCH is always a Bus Master. Writes to this bit position have no effect. Memory Access Enable (MAE). (Not implemented; hardwired to 1). Writes to this bit position have no effect I/O Access Enable (IOAE). (Not implemented by the GMCH: hardwired to 0). Writes to this bit position have no effect 34 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.4.4. PCISTSPCI Status Register (Device 0) Address Offset: Default Value: Access: Size: 06–07h 0080h Read Only, Read/Write Clear 16 bits PCISTS is a 16 bit status register that reports the occurrence of error events on the hub interface. 15 Detected Par Error (HW=0) 14 Sig Sys Error 13 Recog Mast Abort Sta 12 Rec Target Abort Sta (HW=0) 4 Cap List (HW=0) 11 Sig Target Abort Sta (HW=0) 10 DEVSEL# Timing (HW=00) 9 8 Data Par Detected (HW=0) 7 FB2B (HW=1) 6 Reserved 5 3 Reserved 0 Bit 15 14 Descriptions Detected Parity Error (DPE) —RO. This bit is hardwired to 0. Writes to this bit position have no effect. Signaled System Error (SSE)—RWC. This bit is set to 1 when the GMCH Device #0 generates an SERR message over hub interface for any enabled Device #0 error condition. Device #0 error conditions are enabled in the PCICMD register. Device #0 error flags are read/reset from the PCISTS register. Software sets SSE to 0 by writing a 1 to this bit. (Note: the only SERR condition for GMCH is Received Target Abort, therefore there are no other SERR enable bits in the GMCH ). Received Master Abort Status (RMAS) —RWC. This bit is set when the GMCH generates a HubInterface request that receives a Master Abort completion packet. Software clears this bit by writing a 1 to it. Received Target Abort Status (RTAS) —RWC. This bit is set when the GMCH generates a Hub Interface request that receives a Target Abort completion packet. Software clears this bit by writing a 1 to it. Signaled Target Abort Status (STAS) —RO. (Not implemented; hardwired to a 0). Writes to this bit position have no effect. DEVSEL# Timing (DEVT) —RO. These bits are hardwired to “00”. Writes to these bit positions have no effect. Device #0 does not physically connect to PCI0. These bits are set to “00” (fast decode) so that optimum DEVSEL timing for PCI0 is not limited by the GMCH. Data Parity Detected (DPD) —RO. This bit is hardwired to a 0. Writes to this bit position have no effect. Fast Back-to-Back (FB2B) —RO. This bit is hardwired to 1. Writes to these bit positions have no effect. Device #0 does not physically connect to PCI. This bit is set to 1 (indicating fast back-to-back capability) so that the optimum setting for PCI is not limited by the GMCH. Reserved. Capability List (CLIST)—RO. This bit is hardwired to 0, to indicate to the configuration software that this device/function does not implement a new list of features, and that there is NO CAPPTR. Reserved. 13 12 11 10:9 8 7 6:5 4 3:0 Datasheet 35 Intel 82810/82810-DC100 (GMCH) ® R 3.4.5. RIDRevision Identification Register (Device 0) Address Offset: Default Value: Access: Size: 08h 02h Read Only 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 7:0 Description Revision Identification Number. This is an 8-bit value that indicates the revision identification number for the GMCH device #0. For the A-2 Stepping, this value is 02h. 3.4.6. SUBCSub-Class Code Register (Device 0) Address Offset: Default Value: Access: Size: 0Ah 00h Read Only 8 bits This register contains the Sub-Class Code for the GMCH Device #0. This code is 00h indicating a Host Bridge device. The register is read only. Bit 7:0 Description 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. 3.4.7. BCCBase Class Code Register (Device 0) Address Offset: Default Value: Access: Size: 0Bh 06h Read Only 8 bits This register contains the Base Class Code of the GMCH Device #0. This code is 06h indicating a Bridge device. This register is read only. Bit 7:0 Description Base Class Code (BASEC). This is an 8-bit value that indicates the Base Class Code for the GMCH. This code has the value 06h, indicating a Bridge device. 36 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.4.8. MLTMaster Latency Timer Register (Device 0) Address Offset: Default Value: Access: Size: 0Dh 00h Read Only 8 bits MLT Function has moved to the ICH/ICH0, therefore this register is not implemented in the GMCH. Bit 7:0 Descriptions Master Latency Timer Value. This read only field always returns 0’s. 3.4.9. HDRHeader Type Register (Device 0) Offset: Default: Access: Size: 0Eh 00h Read Only 8 bits This register identifies the header layout of the configuration space. No physical register exists at this location. Bit 7:0 Descriptions Header Type. This read only field always returns 0’s. 3.4.10. SVIDSubsystem Vendor Identification Register (Device 0) Offset: Default: Access: Size: 2C–2Dh 0000h Read/Write Once 16 bits Bit 15:0 Description Subsystem Vendor ID—R/WO. This value is used to identify the vendor of the 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. Datasheet 37 Intel 82810/82810-DC100 (GMCH) ® R 3.4.11. SIDSubsystem Identification Register (Device 0) Offset: Default: Access: Size: 2E–2Fh 0000h Read/Write Once 16 bits Bit 15:0 Description Subsystem ID—R/WO. 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. 3.4.12. CAPPTRCapabilities Pointer (Device 0) Offset: Default: Access: Size: 34h 00h Read Only 8 bits The CAPPTR provides the offset that is the pointer to the location where the AGP registers are located. Bit 7:0 Description Pointer to the Start of AGP Register Block. Since there is no AGP bus on the GMCH, this field is set to 00h. 38 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.4.13. GMCHCFGGMCH Configuration Register (Device 0) Offset: Default: Access: Size: 7 Reserved 6 Processor Latency Timer 50h 60h Read/Write, Read Only 8 bits 5 Reserved 4 3 DRAM Pg Closing Policy 2 Reserved 1 D8 Hole Enable 0 CD Hole Enable Bit 7 6 Reserved Processor Latency Timer (CLT). Description 1 = A “deferrable” processor cycle is only Deferred after it has been held in a “Snoop Stall” for 31 clocks and another ADS# has arrived. 0 = A “deferrable” processor cycle is Deferred immediately after the GMCH receives another ADS# 5:4 3 Reserved DRAM Page Closing Policy (DPCP). This bit controls whether the GMCH will “precharge bank” or “precharge all” during the service of a page miss. 1 = The GMCH prechanges all during the service of a page miss. 0 = The GMCH prechanges bank during the service of a page miss. 2 1 Reserved D8 Hole Enable (D8HEN). 1 = Enable. All accesses to the address range 000D8000h–000DFFFh are forwarded on to the ICH, independent of the programming of the PAM registers. 0 = Disable. The “D8 Hole” region is controlled by bits 3:2 of the PAM registers. 0 CD Hole Enable ( CDHEN ). 1 = Enable. All accesses to the address range 000DC000h–000DFFFFh are forwarded on to ICH, independent of the programming of the PAM register. 0 = Disable. The “CD Hole” region is controlled by bits 3 & 2 of the PAM Register. Datasheet 39 Intel 82810/82810-DC100 (GMCH) ® R 3.4.14. PAMR—Programmable Attributes Register (Device 0) Address Offset: Default Value: Access: Size: 51h 00h Read/Write 8 bits The Programmable Attributes Register controls accesses to the memory range 000C0000h to 000FFFFFh. 7 Seg_F Access Control 6 5 Seg_E Access Control 4 3 2 1 0 Seg_D Access Control Seg_C Access Control Bit 7:6 Description Seg_F Access Control. This field controls accesses to 000F0000 to 000FFFFF. 00 = Disabled, all accesses are forwarded to the ICH 01 = Read Only, reads are directed to system memory DRAM and writes are forwarded to the ICH 10 = Write Only, writes are directed to system memory DRAM and reads are forwarded to the ICH 11 = Read/Write, all accesses are directed to system memory DRAM. 5:4 Seg_E Access Control. This field controls accesses to 000E0000 to 000EFFFF. 00 = Disabled, all accesses are forwarded to the ICH 01 = Read Only, reads are directed to system memory DRAM and writes are forwarded to the ICH 10 = Write Only, writes are directed to system memory DRAM and reads are forwarded to the ICH 11 = Read/Write, all accesses are directed to system memory DRAM. 3:2 Seg_D Access Control. This field controls accesses to 000D0000 to 000DFFFF. 00 = Disabled, all accesses are forwarded to the ICH 01 = Read Only, reads are directed to system memory DRAM and writes are forwarded to the ICH 10 = Write Only, writes are directed to system memory DRAM and reads are forwarded to the ICH 11 = Read/Write, all accesses are directed to system memory DRAM. 1:0 Seg_C Access Control. This field controls accesses to 000C0000 to 000CFFFF. 00 = Disabled, all accesses are forwarded to the ICH 01 = Read Only, reads are directed to system memory and writes are forwarded to the ICH 10 = Write Only, writes are directed to system memory and reads are forwarded to the ICH 11 = Read/Write, all accesses are directed to system memory. 40 Datasheet R Intel 82810/82810-DC100 (GMCH) CD Hole (DC000h–DFFFFh) This 16 KB area is controlled by 2 sets of attribute bits. Host-initiated cycles in this region are forwarded to the ICH based upon the programming of PAM[3:2] and the CDHEN bit in the GMCHCFG register. Video Buffer Area (A0000h–BFFFFh) This 128 KB area is not controlled by attribute bits. The host-initiated cycles in this region are always forwarded to either the Graphics device or to the ICH unless this range is accessed in SMM mode. Routing of these accesses is controlled by the Graphics Mode Select field of the SMRAM register. This area can be programmed as SMM area via the SMRAM register. This range can not be accessed from the hub interface. ® 3.4.15. DRPDRAM Row Population Register (Device 0) Address Offset: Default Value: Access: Size: 52h 00h Read/Write (read only) 8 bits GMCH supports 4 physical rows of system memory in 2 DIMMs. The width of a row is 64 bits. The DRAM Row Population Register defines the population of each Side of each DIMM. Note: this entire register becomes read only when the SMM Space Locked (D_LCK) bit is set in the SMRAMSystem Management RAM Control Register (offset 70h). 15 DIMM 1 Population 4 3 DIMM 0 Population 0 Bit 7:4 3:0 Description DIMM 1 Population. This field indicates the population of DIMM 1. (See table below ) DIMM 0 Population. This field indicates the population of DIMM 0. (See table below ) Datasheet 41 Intel 82810/82810-DC100 (GMCH) Table 4. Programming DRAM Row Population Register Fields Field Value (Hex) 0 1 3 4 5 6 7 7 8 8 8 9 9 A A B B B C C D E E F Size 0 MB 8 MB 16 MB 16 MB 24 MB 32 MB 32 MB 32 MB 48 MB 48 MB 48 MB 64 MB 64 MB 64 MB 64 MB 96 MB 96 MB 96 MB 128 MB 128 MB 128 MB 192 MB 192 MB 256 MB 16Mb 16Mb 16Mb 16Mb 16Mb 64Mb 128Mb Mixed 64Mb Mixed 64Mb 128Mb 64Mb 128Mb 64Mb 128Mb Mixed 64Mb 128Mb 128Mb 128Mb Mixed 128Mb Technology Population Empty 4x(1Mx16) 4x(1Mx16) 8x(2Mx8) 8x(2Mx8) 8x(2Mx8) 4x(4Mx16) 2x(4Mx32) 4x(4Mx16) 4x(4Mx16) 2x(4Mx32) 4x(4Mx16) 2x(4Mx32) 8x(8Mx8) 4x(8Mx16) 8x(8Mx8) 4x(8Mx16) 4x(8Mx16) 8x(8Mx8) 4x(8Mx16) 8x(16Mx8) 8x(16Mx8) 8x(16Mx8) 8x(16Mx8) Population Empty Empty 4x(1Mx16) Empty 4x(1Mx16) 8x(2Mx8) Empty Empty 8x(2Mx8) 2x(2Mx32) 2x(2Mx32) 4x(4Mx16) 2x(4Mx32) Empty Empty 4x(4Mx16) 2x(4Mx32) 4x(4Mx16) 8x(8Mx8) 4x(8Mx16) Empty 4x(8Mx16) 8x(8Mx8) 8x(16Mx8) ® R 42 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.4.16. DRAMTDRAM Timing Register (Device 0) Address Offset: Default Value: Access: Size: 53h 08h Read/Write 8 bits The DRAMT Register controls the operating mode and the timing of the DRAM Controller. 7 SDRAM Mode Select 5 4 DRAM Cycle Time 3 Intel Reserved 2 CAS# Latency 1 SDRAM RAS# to CAS# Dly 0 SDRAM RAS# Precharge Bit 7:5 Description SDRAM Mode Select (SMS). These bits select the operational mode of the GMCH DRAM interface. The special modes are intended for initialization at power up. SMS 000 001 010 011 NOP Command Enabled. All Bank Precharge Enable. Mode Register Set Enable. Mode DRAM in Self-Refresh Mode, Refresh Disabled (Default) Normal Operation, refresh 15.6usec Normal Operation, refresh 7.8usec Reserved In this mode all processor cyscles to SDRAM result in a NOP Command on SDRAM interface. In this mode processor cycles to SDRAM result in an all bank precharge command on the SDRAM interface. In this mode all processor cycles to SDRAM result in a mode register set command on the SDRAM interface. The Command is driven on the SMAA[11:0] and the SBS[0] lines. SMAA[2:0] must always be driven to 010 for burst of 4 mode. SMAA[3] must be driven to 1 for interleave wrap type. SMAA[4] needs to be driven to the value programmed in the CAS# Latency bit. SMAA[6:5] should always be driven to 01. SMAA[11:7] and SBS[0] must be driven to 000000. BIOS must calculate and drive the correct host address for each row of memory such that the correct command is driven on the SMAA[11:0] and SBS[0] lines. In this mode all processor cycles to SDRAM result in a CBR cycle on the SDRAM interface. CBR Enable. Note: BIOS must take into consideration SMAB inversion when programming DIMM 2. 4 DRAM Cycle Time ( DCT ). This bit controls the number of SCLKs for an access cycle. Bit4 0 1 3 Tras 5 SCLKs 6 SCLKs Trc 7 SCLKs (Default) 8 SCLKs Intel Reserved. Datasheet 43 Intel 82810/82810-DC100 (GMCH) Bit 2 Description CAS# Latency (CL). This bit controls the number of CLKs between when a read command is sampled by the SDRAMs and when the GMCH samples read data from the SDRAMs. 0 = 3 SCLKs (Default) 1 = 2 SCLKs 1 SDRAM RAS# to CAS# Delay (SRCD). This bit controls the number of SCLKs from a Row Activate command to a read or write command. 0 = 3 SCLKs (Default) 1 = 2 SCLKs 0 SDRAM RAS# Precharge (SRP). This bit controls the number of SCLKs for RAS# precharge. 0 = 3 SCLKs (Default) 1 = 2 SCLKs ® R 3.4.17. FCHCFixed DRAM Hole Control Register (Device 0) Offset: Default: Access: Size: 58h 00h Read/Write 8 bits This 8-bit Register Controls 1 fixed DRAM holes: 15–16MB. 7 Hole Enable 6 Reserved 0 Bit 7 Description Hole Enable (HEN)—RW. This Bit enables a memory hole in DRAM space. Host cycles matching a enabled hole are passed on to the ICH/ICH0 through the Hub Interface. Hub Interface cycles matching an enabled hole are ignored by the GMCH. Note that the hole is not re-mapped 0 = Disabled (Default) 1 = Enabled (15MB–16MB; 1MB size) 6:0 Reserved 44 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.4.18. SMRAMSystem Management RAM Control Register (Device 0) Address Offset: Default Value: Access: Size: 70h 00h Read/Write 8 bits The SMRAM register controls how accesses to Compatible and Extended SMRAM spaces are treated, and how much (if any) memory used from the System to support both SMRAM and Graphics Local Memory needs. 7 Graphics Mode Select 6 5 Upper SMM Select 4 3 Lower SMM Select 2 1 SMM Space Locked 0 E_SMRA M_ERR Bit 7:6 Description Graphics Mode Select (GMS). This field is used to enable/disable the internal graphics device and select the amount of system memory that is used to support the internal graphics device. 00 = Graphics Device Disabled, No memory used (Device 1 is not accessible in this case) 01 = Reserved 10 = Graphics Device Enabled, 512 KB of memory used 11 = Graphics Device Enabled 1 MB of memory used Note: When the Graphics Device is Disabled (00) the graphics device and all of its memory and I/O functions are disabled and the clocks to this logic are turned off, memory accesses to the VGA range. The 512 KB and 1 MB space selected by this field is used by video BIOS for handling support of VGA when no GMCH graphics driver is present (e.g., a DOS boot). (A0000h–BFFFFh) are forwarded to the hub interface, and no system memory is used to support the internal graphics device. When this field is non-zero, the graphics device of the GMCH and all of its memory and I/O functions are enabled, all non-SMM memory accesses to the VGA range are handled internally and the selected amount of system memory (0, 512 KB or 1 MB) is used from system memory to support the internal graphics device. Once D_LCK is set, these bits becomes read only. Datasheet 45 Intel 82810/82810-DC100 (GMCH) Bit 5:4 Description Upper SMM Select ( USMM ). This field is used to enable/disable the various SMM memory ranges above 1Meg. TSEG is a block of memory (Used from System Memory at [TOM-Size]: [TOM]) that is only accessible by the processor and only while operating in SMM mode. HSEG is a Remap of the AB segment at FEEA0000 : FEEBFFFF. Both of these areas, when enabled, are usable as SMM RAM, Non-SMM Operations that use these address ranges are forwarded to hub interface. HSEG is ONLY enabled if LSMM = 00. 00 = TSEG and HSEG are both Disabled 01 = TSEG is Disabled, HSEG is Conditionally Enabled 10 = TSEG is Enabled as 512 KB and HSEG is Conditionally Enabled 11 = TSEG is Enabled as 1 MB and HSEG is Conditionally Enabled Once D_LCK is set, these bits becomes read only. 3:2 Lower SMM Select ( LSMM ). This field controls the definition of the A&B segment SMM space 00 = AB segment Disabled 01 = AB segment Enabled as General System RAM 10 = AB segment Enabled as SMM Code RAM Shadow. Only SMM Code Reads can access DRAM in the AB segment, SMM Data operations and all Non-SMM Operations go to either the internal Graphics Device or are broadcast on hub interface. 11 = AB segment Enabled as SMM RAM. All SMM operations to the AB segment are serviced by DRAM, all Non-SMM Operations go to either the internal Graphics Device or are broadcast on hub interface. When D_LCK is set bit 3 becomes Read_Only, and bit 2 is Writable ONLY if bit 3 is a “1”. 1 SMM Space Locked (D_LCK). When D_LCK is set to 1 then D_LCK, GMS, USMM, and the most significant bit of LSMM become read only. D_LCK can be set to 1 via a normal configuration space write but can only be cleared by a power-on reset. The combination of D_LCK and LSMM provide convenience with security. The BIOS can use LSMM=01 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 LSMM function. This bit also Locks the DRP register. E_SMRAM_ERR (E_SMERR). This bit is set when processor accesses the defined memory ranges in Extended SMRAM (HSEG or TSEG) while not in SMM mode. It is the software’s responsibility to clear this bit. The software must write a 1 to this bit to clear it This bit is Not set for the case of an Explicit Write Back operation. ® R 0 46 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.4.19. MISCCMiscellaneous Control Register (Device 0) Address Offset: Default Value: Access: 72–73h 0000h Read/Write This register contain miscellaneous control bits for the GMCH. Bits[7:3] are locked (read-only) when MISCC[P_CLK; bit 3] = 1. 15 Reserved 8 7 Read Power Throttle Control 6 5 Write Power Throttle Control 4 3 Reserved 1 0 GFX Local Mem Win Size Sel Bit 15:8 7:6 Reserved Description Read Power Throttle Control. These bits select the Power Throttle Bandwidth Limits for Read operations to System Memory. 00 = No Limit (Default) 01 = Limit at 87 ½ % 10 = Limit at 75 % 11 = Limit at 62 ½ % 5:4 Write Power Throttle Control. These bits select the Power Throttle Bandwidth Limits for Write operations to System Memory. 00 = No Limit (Default) 01 = Limit at 62.5% 10 = Limit at 50% 11 = Limit at 37.5% 3 Power Throttle Lock (P_LCK). 1 = Locked. Bits 7:3 of the MISCC register are read-only. Once this bit is set to 1, it can only be cleared to 0 by a hardware reset. 0 = Not locked. 2:1 0 Reserved. Graphics Display Cache Window Size Select. 0 = 64 MB (default) 1 = 32 MB. See GMADR Register (Device 1). Datasheet 47 Intel 82810/82810-DC100 (GMCH) ® R 3.4.20. MISCC2Miscellaneous Control 2 Register (Device 0) Address Offset: Default Value: Access: 80h 00h Read/Write This register controls miscellaneous functionality in the GMCH. 7 Reserved 3 2 Palette Load Select 1 Instr. Parser Unit-Lrvel Clock Enable 0 Intel Reserved Bit 7:3 2 Reserved Description Palette Load Select. This bit controls how the palette is loaded in the GMCH. This bit must be programmed to 1 for proper operation. 1 = Enable. 0 = Disable. Do NOT program to 0. 1 Instruction Parser Unitl-Level Clock Gating Enable. This bit controls the unit-level clock gating in the Instruction Parser. This bit must be programmed to 1 for proper operation. 1= Enable. 0 = Disable. Do NOT program to 0. 0 Reserved 48 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.4.21. BUFF_SC—System Memory Buffer Strength Control Register (Device 0) Address Offset: Default Value: Access: 92–93h FFFFh Read/Write This register programs the system memory DRAM interface signal buffer strengths. The programming of these bits should be based on DRAM density (x8, x16, or x32), DRAM technology (16Mb, 64Mb, 128Mb), rows populated, etc.. Note that x4 DRAM are not supported,even if registered DIMMs are used. DIMMs wth ECC are also not supported and BIOS upon detection of ECC via SPD, should report to the user that ECC DIMM timings are not supported by the GMCH. 15 SCS3# Buffer Strength 14 SCS2# Buffer Strength 13 SCS1# Buffer Strength 12 SCS0# Buffer Strength 11 SMAA[7:4] Buffer Strength 10 9 SMAB[7:4]# Buffer Strength 8 7 CKE1 Buffer Strength 6 5 CKE0 Buffer Strength 4 3 MD and DQM Buffer Strength 2 1 0 Control Buffer Strength Bit 15 Description SCS0# Buffer Strength. This field sets the buffer strength for system memory chip select SCS0#. 0 = 3x 1 = 2x 14 SCS1# Buffer Strength. This field sets the buffer strength for system memory chip select SCS1#. 0 = 3x 1 = 2x 13 SCS2# Buffer Strength. This field sets the buffer strength for system memory chip select SCS2#. 0 = 3x 1 = 2x 12 SCS3# Buffer Strength. This field sets the buffer strength for system memory chip select SCS3#. 0 = 3x 1 = 2x 11:10 SMAA[7:4] Buffer Strength. This field sets the buffer strength for the SMAA[7:4] buffers. 00 = 4x 01 = 3x 10 = 2x 11 = 1x Datasheet 49 Intel 82810/82810-DC100 (GMCH) Bit 9:8 Description SMAB[7:4]# Buffer Strength. This field sets the buffer strength for the SMAB[7:4]# buffers. 00 = 4x 01 = 3x 10 = 2x 11 = 1x 7:6 CKE1 Buffer Strength. This field sets the buffer strength for the CKE1 buffers. 00 = 4x 01 = 3x 10 = 2x 11 = 1x 5:4 CKE0 Buffer Strength. This field sets the buffer strength for the CKE0 buffers. 00 = 4x 01 = 3x 10 = 2x 11 = 1x 3:2 SMD[63:0] and SDQM[7:0] Buffer Strength. This field sets the buffer strength for the SMD[63:0] and SDQM[7:0] pins. 00 = 2.5x 01 = 1.5x 10 = 1x 11 = 1x 1:0 SWE#, SCAS#, SRAS#, MAA[11:8, 3:0], SBS[1:0] Control Buffer Strength. This field sets the buffer strength for the SWE#, SCAS#, SRAS#, MAA[11:8, 3:0], SBS[1:0] pins. 00 = 4x 01 = 3x 10 = 2x 11 = 1x ® R 50 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.5. Graphics Device Registers – (Device 1) Table 5 shows the GMCH configuration space for device #1. Table 5. GMCH Configuration Space (Device 1) Address Offset 00–01h 02–03h 04–05h 06–07h 08h 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh 10–13h 14–17h 18–2Bh 2C–2Dh 2E–2Fh 30–33h 34 35–3Bh 3Ch 3Dh 3Eh 3Fh 40–DBh DC–DDh DE–DFh E0–E1h E2–FFh Register Symbol VID1 DID1 PCICMD1 PCISTS1 RID1 PI SUBC1 BCC1 CLS MLT1 HDR1 BIST GMADR MMADR  SVID SID ROMADR CAPPOINT  INTRLINE INTRPIN MINGNT MAXLAT  PM_CAPID PM_CAP PM_CS  Register Name Vendor Identification Device Identification PCI Command Register PCI Status Register Revision Identification Programming Interface Sub-Class Code Base Class Code Cache Line Size Register Master Latency Timer Header Type BIST Register Graphics Memory Range Address Memory Mapped Range Address Reserved Subsystem Vendor ID Subsystem ID Video Bios ROM Base Address Capabilities Pointer Reserved Interrupt Line Register Interrupt Pin Register Minimum Grant Register Maximum Latency Register Reserved Power Management Capabilities ID Power Management Capabilities Power Management Control Reserved Default Value 8086h 7121h/7123h 0004h 02B0h 02h 00h 00h 03h 00h 00h 01h 00h 00000008h 00000000h  0000h 0000h 00000000h DCh  00h 01h 00h 00h  0001h 0021h 0000h  Access RO RO R/W RO, R/WC RO RO RO RO RO RO RO RO R/W R/W  R/WO R/WO RO RO  R/W RO RO RO  RO RO R/W  Datasheet 51 Intel 82810/82810-DC100 (GMCH) ® R 3.5.1. VIDVendor Identification Register (Device 1) Address Offset: Default Value: Attribute: 00h−01h 8086h Read Only The VID Register contains the vendor identification number. This 16-bit register combined with the Device Identification Register uniquely identify any PCI device. Writes to this register have no effect. Bit 15:0 Description Vendor Identification Number. This is a 16-bit value assigned to Intel. 3.5.2. DIDDevice Identification Register (Device 1) Address Offset: Default Value: Attribute: 02h−03h 82810 = 7121h 82810-DC100 = 7123h Read Only This 16-bit register combined with the Vendor Identification register uniquely identifies any PCI device. Writes to this register have no effect. Bit 15:0 Description Device Identification Number. This is a 16 bit value assigned to the internal graphics device of the GMCH. 52 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.5.3. PCICMDPCI Command Register (Device 1) Address Offset: Default: Access: 04h−05h 0004h Read Only, Read/Write This 16-bit register provides basic control over the GMCH’s ability to respond to PCI cycles. The PCICMD Register in the GMCH disables the GMCH PCI compliant master accesses to system memory. 15 Reserved (0) 10 9 FB2B (Not Impl) 8 SERR En (Not Impl) 7 Addr/Data Stepping (Not Impl) 6 Parity Error En (Not Impl) 5 VGA Pal Sn (Not Impl) 4 Mem WR & Inval En (Not Impl) 3 Special Cycle En (Not Impl) 2 Bus Master En (Enabled) 1 Mem Acc En 0 I/O Acc En Bit 15:10 9 8 7 6 5 4 3 2 1 Reserved. Descriptions Fast Back-to-Back (FB2B)RO. (Not Implemented). Hardwired to 0. SERR# Enable (SERRE) RO. (Not Implemented). Hardwired to 0. Address/Data SteppingRO. (Not Implemented). Hardwired to 0. Parity Error Enable (PERRE) RO. (Not Implemented). Hardwired to 0. Video Palette Snooping (VPS) RO. This bit is hardwired to 0 to disable snooping. Memory Write and Invalidate Enable (MWIE) RO. Hardwired to 0. The internal graphics device of the GMCH does not support memory write and invalidate commands. Special Cycle Enable (SCE) RO. This bit is hardwired to 0. The internal graphics device of the GMCH ignores Special cycles. Bus Master Enable (BME) RO. Hardwired to 1 to enable the internal graphics device of the GMCH to function as a PCI compliant master. Memory Access Enable (MAE) R/W. This bit controls the internal graphics device of the GMCH’s response to memory space accesses. 0 = Disable (default). 1 = Enable. 0 I/O Access Enable (IOAE) R/W. This bit controls the internal graphics device of the GMCH’s response to I/O space accesses. 0 = Disable (default). 1 = Enable. Datasheet 53 Intel 82810/82810-DC100 (GMCH) ® R 3.5.4. PCISTSPCI Status Register (Device 1) Address Offset: Default Value: Access: 06h−07h 02B0h Read Only 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 GMCH hardware. 15 Detected Par Error (HW=0) 14 Sig Sys Error (HW=0) 13 Recog Mast Abort Sta (HW=0) 12 Rec Target Abort Sta (HW=0) 11 Sig Target Abort Sta (HW=0) 10 DEVSEL# Timing (HW=01) 9 8 Data Par Detected (HW=0) 7 FB2B (HW=1) 6 Reserved 5 Reserved 4 Cap List (HW=1) 3 Reserved 0 Bit 15 14 13 12 11 10:9 Descriptions Detected Parity Error (DPE) RO. Since the internal graphics device of the GMCH does not detect parity, this bit is always set to 0. Signaled System Error (SSE) RO. The internal graphics device of the GMCH device never asserts SERR#, therefore this bit is hardwired to 0. Received Master Abort Status (RMAS) RO. The internal graphics device of the GMCH device never gets a Master Abort, therefore this bit is hardwired to 0. Received Target Abort Status (RTAS) RO.. The internal graphics device of the GMCH device never gets a Target Abort, therefore this bit is hardwired to 0. Signaled Target Abort Status (STAS). Hardwired to 0. The internal graphics device of the GMCH does not use target abort semantics. DEVSEL# Timing (DEVT) RO. This 2-bit field indicates the timing of the DEVSEL# signal when the internal graphics device of the GMCH responds as a target. Hardwired to 01 to indicate that the internal graphics device of the GMCH is a medium decode device. Data Parity Detected (DPD) R/WC. Since Parity Error Response is hardwired to disabled (and the internal graphics device of the GMCH does not do any parity detection), this bit is hardwired to 0. Fast Back-to-Back (FB2B). Hardwired to 1. The internal graphics device of the GMCH accepts fast back-to-back when the transactions are not to the same agent. Reserved. CAP LISTRO. 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. Reserved. 8 7 6:5 4 3:0 54 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.5.5. RIDRevision Identification Register (Device 1) Address Offset: Default Value: Access: 08h 02h Read Only This register contains the revision number of the internal graphics device of the GMCH. These bits are read only and writes to this register have no effect. Bit 7:0 Description Revision Identification Number. This is an 8-bit value that indicates the revision identification number for the internal graphics device of the GMCH. The four lsb’s are for process differentiation and the four msbs indicate stepping. For the A-2 Stepping, this value is 02h 3.5.6. PI-Programming Interface Register (Device 1) Address Offset: Default Value: Access: 09h 00h Read Only This register contains the device programming interface information for the GMCH. Bit 7:0 Description Programming Interface (PI). 00h=Hardwired as a Display controller. 3.5.7. SUBC1—Sub-Class Code Register (Device 1) Address Offset: Default Value: Access: Size: 0Ah 00h Read Only 8 bits This register contains the Sub-Class Code for the GMCH Function #1. This code is 00h indicating a VGA compatible device. The register is read only. Bit 7:0 Description Sub-Class Code (SUBC). This is an 8-bit value that indicates the category of Display controller of the GMCH. The code is 00h indicating a VGA compatible device. Datasheet 55 Intel 82810/82810-DC100 (GMCH) ® R 3.5.8. BCC1—Base Class Code Register (Device 1) Address Offset: Default Value: Access: Size: 0Bh 03h Read Only 8 bits This register contains the Base Class Code of the GMCH Function #1. This code is 03h indicating a Display controller. This register is read only. Bit 7:0 Description Base Class Code (BASEC). This is an 8-bit value that indicates the Base Class Code for the GMCH. This code has the value 03h, indicating a Display controller. 3.5.9. CLSCache Line Size Register (Device 1) Address Offset: Default Value: Access: 0Ch 00h Read only The internal graphics device of the GMCH does not support this register as a PCI slave. Bit 7:0 Description Cache Line Size (CLS). This field is hardwired to 0’s. The internal graphics device of the GMCH as a PCI compliant master does not use the Memory Write and Invalidate command and, in general, does not perform operations based on cache line size. 3.5.10. MLTMaster Latency Timer Register (Device 1) Address Offset: Default Value: Access: 0Dh 00h Read Only The internal graphics device of the GMCH does not support the programmability of the master latency timer because it does not perform bursts. Bit 7:0 Description Master Latency Timer Count Value. Hardwired to 0s. 56 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.5.11. HDRHeader Type Register (Device 1) Address Offset: Default Value: Access: 0Eh 00h Read Only This register contains the Header Type of the internal graphics device of the GMCH. Bit 7:0 Description Header Type (HTYPE). This is an 8-bit value that indicates the Header Type for the internal graphics device of the GMCH. This code has the value 00h, indicating a basic (i.e., single function) configuration space format. 3.5.12. BISTBuilt In Self Test (BIST) Register (Device 1) Address Offset: Default Value: Access: 0Fh 00h Read Only This register is used for control and status of Built In Self Test (BIST) for the internal graphics device of the GMCH. 7 BIST Supported (HW=0) 6 Reserved 0 Bit 7 6:0 Descriptions BIST Supported. BIST is not supported. This bit is hardwired to 0. Reserved. Datasheet 57 Intel 82810/82810-DC100 (GMCH) ® R 3.5.13. GMADRGraphics Memory Range Address Register (Device 1) Address Offset: Default Value: Access: 10−13h 00000008h Read/Write, Read Only This register requests allocation for the internal graphics device of the GMCH local memory. The allocation is for either 32 MB or 64 MB of memory space (selected by bit 0 of the Device 0 MISCC Register) and the base address is defined by bits [31:25,24]. 31 Memory Base Address (addr bits [31:26]) 26 25 64 MB Addr Mask 24 Address Mask (HW=0; 32MB addr range) 16 15 Address Mask (cont) (HW=0; 32MB addr range) 4 3 Prefetch Mem En (HW=1) 2 Memory Type (HW=0; 32MB addr) 1 0 Mem/IO Space (HW=0) Bit 31:26 25 Descriptions Memory Base AddressR/W. Set by the OS, these bits correspond to address signals [31:26]. 64M Address Mask—RO , R/W. If Device 0 MISCC Reg bit 0 = 0 then this bit is Read Only with a value of “0”, indicating a memory range of 64MB, if Device 0 MISCC Reg bit 0 = 1 then this bit is R/W, indicating a memory range of 32 MB. Address MaskRO. Hardwired to 0s to indicate 32 MB address range. Prefetchable MemoryRO. Hardwired to 1 to enable prefetching. Memory TypeRO. Hardwired to 0 to indicate 32-bit address. Memory/IO SpaceRO. Hardwired to 0 to indicate memory space. 24:4 3 2:1 0 58 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.5.14. MMADRMemory Mapped Range Address Register (Device 1) Address Offset: Default Value: Access: 14−17h 00000000h Read/Write, Read Only This register requests allocation for the internal graphics device of the GMCH registers and instruction ports. The allocation is for 512 KB and the base address is defined by bits [31:19]. 31 Memory Base Address (addr bits [31:19]) 19 18 16 Address Mask (HW=0; 512 KB addr range) 15 Address Mask (cont) (HW=0; 512 KB addr range) 4 3 Prefetch Mem En (HW=0) 2 Memory Type (HW=0; 32 MB addr) 1 0 Mem/IO Space (HW=0) Bit 31:19 18:4 3 2:1 0 Descriptions Memory Base AddressR/W. Set by the OS, these bits correspond to address signals [31:19]. Address MaskRO. Hardwired to 0s to indicate 512 KB address range. Prefetchable MemoryRO. Hardwired to 0 to prevent prefetching. Memory TypeRO. Hardwired to 0s to indicate 32-bit address. Memory / IO SpaceRO. Hardwired to 0 to indicate memory space. 3.5.15. SVIDSubsystem Vendor Identification Register (Device 1) Address Offset: Default Value: Access: Bit 15:0 2C−2Dh 0000h Read/Write Once Descriptions Subsystem Vendor ID—R/WO. This value is used to identify the vendor of the subsystem. The default value is 0000h. 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. Datasheet 59 Intel 82810/82810-DC100 (GMCH) ® R 3.5.16. SIDSubsystem Identification Register (Device 1) Address Offset: Default Value: Access: Bit 15:0 2E−2Fh 0000h Read/Write Once Descriptions Subsystem ID—R/WO. This value is used to identify a particular subsystem. The default value is 0000h. 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. 3.5.17. ROMADRVideo BIOS ROM Base Address Registers (Device 1) Address Offset: Default Value: Access: 30−33h 00000000h Read Only The internal graphics device of the GMCH does not use a separate BIOS ROM, therefore this is hardwired to 0s. 31 ROM Base Address (addr bits [31:19]) 18 17 16 Address Mask (HW=0; 256 KB addr range) 15 Address Mask (cont) (HW=0; 256 KB addr range) 11 10 Reserved (HW=0) 1 0 ROM BIOS En (HW=0) Bit 31:18 17:11 10:1 0 Descriptions ROM Base AddressRO. Hardwired to 0s. Address MaskRO. Hardwired to 0s to indicate 256 KB address range. Reserved. Hardwired to 0s. ROM BIOS EnableRO. 0 = ROM not accessible. 3.5.18. CAPPOINTCapabilities Pointer Register (Device 1) Address Offset: Default Value: Access: Bit 7:0 34h DCh Read Only Descriptions Pointer to the Atart of AGP Register Block. Since there is no AGP bus on the GMCH, this field is set to DCh to point to the Power Management Capabilities ID Register 60 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.5.19. INTRLINEInterrupt Line Register (Device 1) Address Offset: Default Value: Access: 3Ch 00h Read/Write Bit 7:0 Descriptions 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. 3.5.20. INTRPINInterrupt Pin Register (Device 1) Address Offset: Default Value: Access: 3Dh 01h Read Only Bit 7:0 Descriptions Interrupt Pin. As a single function device, GMCH specifies INTA# as its interrupt pin. 01h=INTA#. 3.5.21. MINGNTMinimum Grant Register (Device 1) Address Offset: Default Value: Access: Bit 7:0 3Eh 00h Read Only Descriptions Minimum Grant Value. GMCH does not burst as a PCI compliant master. Bits[7:0]=00h. 3.5.22. MAXLATMaximum Latency Register (Device 1) Address Offset: Default Value: Access: Bit 7:0 3Fh 00h Read Only Descriptions Maximum Latency Value. Bits[7:0]=00h. The GMCH has no specific requirements for how often it needs to access the PCI bus. Datasheet 61 Intel 82810/82810-DC100 (GMCH) ® R 3.5.23. PM_CAPIDPower Management Capabilities ID Register (Device 1) Address Offset: Default Value: Access: 15 NEXT_PTR DCh−DDh 0001h Read Only 8 7 CAP_ID 0 Bits 15:8 7:0 Description NEXT_PTR. This contains a pointer to next item in capabilities list. This the final capability in the list and must be set to 00h. CAP_ID. SIG defines this ID is 01h for power management. 3.5.24. PM_CAPPower Management Capabilities Register (Device 1) Address Offset: Default Value: Access: 15 PME Support (HW=0) DEh−DFh 0021h Read Only 11 10 D2 (HW=0) 9 D1 (HW=0) 8 Reserved 7 Reserved 6 5 Dev Specific Init (HW=1) 4 Aux Pwr Src (HW=0) 3 PME Clock (HW=0) 2 Version (HW=001) 0 Bits 15:11 10 9 8:6 5 4 3 2:0 Description PME Support. This field indicates the power states in which the GMCH may assert PME#. Hardwired to 0 to indicate that the GMCH does not assert the PME# signal. D2. Hardwired to 0 to indicate D2 power management state is not supported. D1. Hardwired to 0 to indicate that D1 power management state is not supported. Reserved. Read as 0s. Device Specific Initialization (DSI). Hardwired to 1 to indicate that special initialization of the GMCH is required before generic class device driver is to use it. Auxiliary Power Source. Hardwired to 0. PME Clock. Hardwired to 0 to indicate the GMCH does not support PME# generation. Version. Hardwired to 001b to indicate there are 4 bytes of power management registers implemented. 62 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.5.25. PM_CS—Power Management Control/Status Register (Device 1) Address Offset: Default Value: Access: 15 PME Sta (HW=0) 14 E0h−E1h 0000h Read/Write 13 12 Data_Select (Reserved) 9 8 PME En Data Scale (Reserved) 7 Reserved 2 1 PowerState 0 Bits 15 14:13 12:9 8 7:2 1:0 Description PME_Status R/WC. This bit is 0 to indicate that the GMCH does not support PME# generation from D3 (cold). Data Scale (Reserved) RO. The GMCH does not support data register. This bit always returns 0 when read, write operations have no effect. Data_Select (Reserved) RO. The GMCH does not support data register. This bit always returns 0 when read, write operations have no effect. PME_EnR/W. This bit is 0 to indicate that PME# assertion from D3 (cold) is disabled. Reserved. Always returns 0 when read, write operations have no effect. PowerStateR/W. This field indicates the current power state of the GMCH and can be used to set the GMCH 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. 00 = D0 01 = Reserved 10 = Reserved 11 = D3 Datasheet 63 Intel 82810/82810-DC100 (GMCH) ® R 3.6. Display Cache Interface (82810-DC100 Only) The Display Cache (DC) interface control registers are located in memory Space. This section describes the DC interface registers. These registers are accessed using [MMADR+Offset]. These registers are only memory mapped (not I/O mapped). The memory map for the 03000h–0FFFFh address offset range is shown in Table 6. Table 6. Memory Map for 03000h–0FFFFh Address Offset Range Address Offset 03000h 03001h 03002h 03003h–03FFFh 04000h–06017h 07000h–0FFFFh Register Symbol DRT DRAMCL DRAMCH    Register Name DRAM Row Type DRAM Control Low DRAM Control High Intel Reserved Intel Reserved Reserved Default Value 00h 17h 08h    Access R/W R/W R/W    3.6.1. DRT—DRAM Row Type Memory Offset Address: Default value: Access: Size: 3000h 00h Read / write 8 bit This 8-bit register identifies whether or not the display cache is populated. Memory mapped only. 7 Reserved 1 0 DRAM Populated Bit 7:1 0 Reserved Description DRAM Populated (DP). The bit in this register indicates whether or not the Display Cache is populated. 0 = No Display Cache 1 = 4MB Display Cache 64 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.6.2. DRAMCL—DRAM Control Low Memory Offset Address: Default value: Access: Size: 7 Reserved 3001h 17h Read / write 8 bit 5 4 Paging Mode Control 3 RAS-toCAS Override 2 CAS# Latency 1 RAS# Riming 0 RAS# Precharge Timing Bit 7:5 4 Reserved Paging Mode Control (PMC) Description 0 = Page Open Mode. In this mode the GMCH memory controller tends to leave pages open. 1 = Page Close Mode. In this mode the GMCH memory controller tends to leave pages closed. 3 RAS-to-CAS Override (RCO). In units of display cache clock periods indicates the RAS#-to-CAS# delay (tRCD). (i.e., row activate command to read/write command) 0 = determined by CL bit (default) 1=2 2 CAS# Latency (CL). In units of local memory clock periods. Bit 0 1 1 CL 2 3 RAS#-to-CAS# delay (tRCD) 2 3 (default) RAS# Timing (RT). This bit controls RAS# active to precharge, and refresh to RAS# active delay (in local memory clocks). Bit 0 1 RAS# act. To precharge (tRAS) 5 7 Refresh to RAS# act. (tRC) 8 10 (default) 0 RAS# Precharge Timing (RPT). This bit controls RAS# precharge (in local memory clocks). 0=2 1 = 3 (default) Datasheet 65 Intel 82810/82810-DC100 (GMCH) ® R 3.6.3. DRAMCH—DRAM Control High Memory Offset Address: Default value: Access: Size: 7 Reserved 3002h 08h Read / write 8 bit 5 4 DRAM Refresh Rate 3 2 Special Mode Select 0 Bit 7:5 4:3 Reserved Description DRAM Refresh Rate (DRR). DRAM refresh is controlled using this field. Disabling refresh results in the eventual loss of DRAM data, although refresh can be briefly disabled without data loss. The field must be set to normal refresh as soon as possible once DRAM testing is completed. 00 = Refresh Disabled 01 = Refresh Enabled (default) 10 = Reserved 11 = Reserved 2:0 Special Mode Select (SMS). These bits select special SDRAM modes used for testing and initialization. The NOP command must be programmed first before any other command can be issued. 000 = Normal SDRAM mode (Normal, default). 001 = NOP Command Enable (NCE). This state forces cycles to DRAM to generate SDRAM NOP commands. 010 = All Banks Precharge Command Enable (ABPCE). This state forces cycles to DRAM to generate an all banks precharge command. 011 = Mode Register Command Enable (MRCE). This state forces all cycles to DRAM to be converted into MRS commands. The command is driven on the LMA[11:0] lines. LMA[2:0] correspond to the burst length, LMA[3] corresponds to the wrap type, and LMA[6:4] correspond to the latency mode. LMA[11:7] are driven to 00000 by the GMCH, The BIOS must select an appropriate host address for each row of memory such that the right commands are generated on the LMA[6:0] lines, taking into account the mapping of host addresses to display cache addresses. 100 = CBR Cycle Enable (CBRCE). This state forces cycles to DRAM to generate SDRAM CBR refresh cycles. 101 = Reserved. 11X = Reserved. 66 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.7. Display Cache Detect and Diagnostic Registers (82810-DC100 Only) The following registers are used for display cache detection and diagnostics. These registers can be accessed via either I/O space or memory space. The memory space addresses listed are offsets from the base memory address programmed into the MMADR register (Device 1, PCI configuration offset 14h). For each register, the memory-mapped address offset is the same address value as the I/O address. 3.7.1. GRXGRX Graphics Controller Index Register I/O (and Memory Offset) Address: Default: Attributes: 7 Reserved (0000) 3CEh 0Uh (U=Undefined) Read/Write 4 3 Graphics Controller Register Index 0 Bit 7:4 3:0 Reserved. Read as 0s. Description Sequencer Register Index. This field selects any one of the graphics controller registers (GR[00:08) to be accessed via the data port at I/O location 3CFh. Datasheet 67 Intel 82810/82810-DC100 (GMCH) ® R 3.7.2. MSRMiscellaneous Output I/O (and Memory Offset) Address: Default: Attributes: 7 Reserved 3C2h  Write; 3CCh Read 00h See Address above 2 1 A0000h− BFFFFh Acc En 0 Reserved Bit 7:2 1 Reserved Descriptions A0000−BFFFFh Access Enable. VGA Compatibility bit enables access to the display cache at A0000h−BFFFFh. When disabled, accesses to system memory are blocked in this region (by not asserting DEVSEL#). This bit does not block processor access to the video linear frame buffer at other addresses. 0 = Prevent processor access to the display cache (default). 1 = Allow processor access to display cache. 0 Reserved 68 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 3.7.3. GR06Miscellaneous Register I/O (and Memory Offset) Address: Default: Attributes: 7 Reserved 3CFh (Index=06h) 0Uh (U=Undefined) Read/Write 4 3 Memory Map Mode 2 1 Reserved 0 Bit 7:4 3:2 Reserved Description Memory Map Mode. These 2 bits control the mapping of the VGA frame buffer into the processor address space as follows: 00 = A0000h − BFFFFh 01 = A0000h − AFFFFh 10 = B0000h − B7FFFh 11 = B8000h − BFFFFh Note: This function is both in standard VGA modes and in extended modes that do not provide linear frame buffer accesses. 1:0 Reserved Datasheet 69 Intel 82810/82810-DC100 (GMCH) ® R 3.7.4. GR10Address Mapping I/O (and Memory Offset) Address: Default: Attributes: 7 Reserved 5 4 Paging to display cache 3CFh (Index=10h) 00h R/W 3 VGA Buffer /Memory Map 2 Packed Mode Enbl 1 Linear Mapping 0 Page Mapping Bit 7:5 4 Reserved Page to Display Cache Enable. 0 = Page to VGA Buffer. 1 = Page to Display Cache. 3 VGA Buffer/Memory Map Select. 0 = VGA Buffer (default) 1 = Memory Map. 2 Packed Mode Enable. 0 = Disable (default) 1 = Enable 1 Linear Mapping (PCI). 0 = Disable (default) 1 = Enable 0 Description Page Mapping Enable. This mode allows the mapping of the vga space allocated in main memory (non local video memory) mode or all of local memory space through the A0000:AFFFF window that is a 64 KB page. 0 = Disable (default) 1 = Enable 3.7.5. GR11Page Selector I/O (and Memory Offset) Address: Default: Attributes: Bit 7:0 3CFh (Index=11h) 00h R/W Description Page Select. Selects a 64KB window within the display cache when Page Mapping is enabled to the display cache. 70 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 4. Functional Description This chapter describes the Graphics and Memory Controller Hub (GMCH) interfaces on-chip functional units. Section 4.1, “System Address Map” provides a system-level address memory map and describes the memory space controls provided by the GMCH. 4.1. System Address Map An Intel® CeleronTM processor system based on the GMCH, supports 4 GB of addressable memory space and 64 KB+3 of addressable I/O space. (The P6 bus I/O addressability is 64KB + 3). There is a programmable memory address space under the 1 MB region that can be controlled with programmable attributes of Write Only, or Read Only. Attribute programming is described in the Configuration Register Description section. This section focuses on how the memory space is partitioned and what these separate memory regions are used for. The I/O address space is discussed in Section 4.1.3. The Intel® CeleronTM processor supports addressing of memory ranges larger than 4 GB. The GMCH Host Bridge claims any access over 4 GB by terminating the transaction (without forwarding it to the hub interface). Writes are terminated by dropping the data, and for reads, the GMCH returns all zeros on the host bus. In the following sections, it is assumed that all of the compatibility memory ranges reside on the hub interface. The exceptions to this rule are the VGA ranges that may be mapped to the internal Graphics Device. Note: The GMCH Memory Map includes a number of programmable ranges, ALL of these ranges MUST be unique and NON-OVERLAPPING. There are NO Hardware Interlocks to prevent problems in the case of overlapping ranges. Accesses to overlapped ranges may produce indeterminate results. 4.1.1. Memory Address Ranges Figure 4 shows a high-level representation of the system memory address map. Figure 5 provides additional details on mapping specific memory regions as defined and supported by the GMCH chipset. Figure 4. System Memory Address Map 4 GB P CI Memory Address Range Local Memory Range Memory Mapped Range T op of the Main Memor y Main Memory Address Range 0 Independentl y Programmable NonOverlappin g M emor y Windows mem_map_s.vsd Datasheet 71 Intel 82810/82810-DC100 (GMCH) Figure 5. Detailed Memory System Address Map System Memory Space 64 GB Extended CPU Memory Space 4 GB PCI Memory FEEC 0000h FEEB FFFFh FEEA 0000h FEE9 FFFFh Size=512 KB – fixed Optional HSEG PCI Memory Graphics Controller (GC) (memory-mapped control/status registers) PCI Memory accesses to GC registers ® R Base=MMADR Reg. (14h); Dev 1 Size=32/64MB; MISCC Reg. (72h); Dev 0 PCI Memory Graphics (virtual) Memory (32MB/64MB) PCI Memory Accesses to Graphics (Virtual) Memory Base=GMADR Reg. (10h); Dev 1 TOM (512 MB Max.) Size=0KB/512KB/1MB; SMRAM Reg. (70h); Dev 0 Size=0KB/512KB/1MB; SMRAM Reg. (70h); Dev 0 PCI Memory 0FFFFFh Optional TSEG Optional Graphics Device Segment F (BIOS Shadow Area, etc.) Main Memory 0F0000h 0EFFFFh Segment E (BIOS Shadow Area, etc.) 0E0000h 0DFFFFh 16 MB Optional ISA Hole 15 MB 0DC000h 0DBFFFh 0D0000h 0CFFFFh 896 KB Optional CD Hole 880 KB Segment D (BIOS Shadow Area, etc.) Segment C (BIOS Shadow Area, etc.) 0C0000h 0BFFFFh Video BIOS (shadowed in memory) Graphics Adapter (128 KB) System/Application SW DOS Compatibility Memory Optionally mapped to the internal GC Std PCI/ISA Video Mem (SMM Mem) 128 KB 0A0000h 09FFFFh DOS Area (640 KB) 000000h 0 KB mem_map2.vsd 1 MB 960 KB 832 KB 100000h 0FFFFFh 1 MB 768 KB C0000h BFFFFh A0000h 9FFFFh 00000h 640 KB 4.1.1.1. Compatibility Area This area is divided into the following address regions: • • • 0–640 KB DOS Area 640–768 KB Video Buffer Area 768 KB–1 MB Memory (BIOS Area). System BIOS area, Extended System BIOS area, and Expansion area 72 Datasheet R Intel 82810/82810-DC100 (GMCH) Table 7 lists the memory segments of interest in the compatibility area. Four of the memory ranges can be enabled or disabled independently for both read and write cycles. One segment (0DC000h to 0DFFFFh) is conditionally mapped to the PCI Bus (via the hub interface). ® Table 7. Memory Segments and their Attributes Memory Segments 000000h–09FFFFh 0A0000h–0BFFFFh 0C0000h–0CFFFFh 0D0000h–0DFFFFh 0DC000h–0DFFFFh 0E0000h–0EFFFFh 0F0000h–0FFFFFh Attributes fixed - always mapped to main DRAM mapped to PCI - configurable as SMM space R/W, WO, RO, Disabled R/W, WO, RO, Disabled Included in above or Disabled R/W, WO, RO, Disabled R/W, WO, RO, Disabled Comments 0 to 640K - DOS Region Video Buffer (physical DRAM configurable as SMM space) BIOS etc Shadow Area BIOS etc Shadow Area BIOS etc Shadow Area, Memory Hole BIOS etc Shadow Area BIOS etc Shadow Area • DOS Area (00000h–9FFFFh). The 640 KB DOS area is always mapped to the main memory controlled by the GMCH. • Video Buffer Area (A0000h–BFFFFh). The 128 Kbyte graphics adapter memory region is normally mapped to a legacy video device (e.g., VGA controller) on PCI via the hub interface. This area is not controlled by the attribute bits and processor -initiated cycles in this region are forwarded to hub interface or the internal graphics device for termination. This region is also the default region for SMM space. Accesses to this range are directed to either PCI (via the hub interface) or the internal graphics device based on the configuration specified in SMRAM[GMS bits] (GMCH Device #0 configuration register) with additional steering information coming from the Device #1 configuration registers and from some of the VGA registers in the graphics device. The control is applied for accesses initiated from any of the system interfaces (i.e., host bus or hub interface). For more details, see the descriptions in the PCI Configuration Registers specified above. SMRAM controls how SMM accesses to this space are treated. • Monochrome Adapter (MDA) Range (B0000h–B7FFFh). SMRAM[GMS bits] (Device #0), PCICMD register bits of Device #1, and bits in some of the VGA registers control this functionality. ( see Section 4.1.1.2). • CD Hole (DC000h–DFFFFh). GMCHCFG[CDHEN] (Device 0) controls the routing of accesses in this region. When CDHEN = 1, all accesses to the address range 000DC000h–000DFFFFh are forwarded on to PCI, independent of the programming of the PAM register. When CDHEN = 0, the CD Hole region is controlled by bits [3:2] of the PAM Register. • BIOS etc Shadow Area (C0000h–FFFFFh). Except for the CD Hole area, access to this range is controlled by the bits of the PAMR register bits. Datasheet 73 Intel 82810/82810-DC100 (GMCH) ® R 4.1.1.2. Extended Memory Area This memory area covers the 100000h (1 MB) to FFFFFFFFh (4 GB-1) address range and it is divided into regions as specified in the following sections. Main DRAM Address Region (0010_0000h to Top of Main Memory) The address range from 1 MB to the top of main memory is mapped to main the DRAM address range controlled by the GMCH. All accesses to addresses within this range, except those listed below, are forwarded by the GMCH to DRAM. • Optional ISA Memory Hole (15 MB–16 MB). A 1 MB ISA memory hole in the main DRAM range can be enabled via the FDHC register (Device 0). Note that this memory is not re-mapped. Accesses to this range are forwarded to PCI (via the hub interface) • TSEG. This Extended SMRAM Address Range, if enabled, occupies the 512 KB or 1 MB range below the Top of Main Memory. The size of TSEG is determined by SMRAM[USMM] (Device 0). When the extended SMRAM space is enabled, non-SMM processor accesses and all other accesses in this range are forwarded to PCI (via the hub interface). When SMM is enabled, the amount of memory available to the system is reduced by the TSEG range. • Optional Graphics Device Memory. This address range provides either 512KB or 1MB of VGA buffer memory for the internal graphics device . If TSEG is enabled, this address range is just below TSEG. If TSEG is not enabled, the Optional Graphics Device VGA buffer range is just below TOM. The Graphics Device buffer memory range is enabled and the size selected via SMRAM[GMS]. PCI Memory Address Region (Top of Main Memory to 4 GB) The address range from the top of main DRAM to 4 GB (top of physical memory space supported by the GMCH) is normally mapped to PCI (via the hub interface), except for the address ranges listed below. There are two sub-ranges within the PCI Memory address range defined as APIC Configuration Space and High BIOS Address Range. The Local Memory Range and the Memory Mapped Range of the internal Graphics Device MUST NOT overlap with these two ranges. • GMCH’s Graphics Controller Status/Control Register Range. A 512 KB space (Error! Reference source not found.) for the graphics controller device’s memory-mapped status/control registers is requested during Plug and Play. The base address is programmed in the MMADR PCI Configuration Register for Device 1. Note that, for legacy support, the VGA registers in the GMCH’s graphics controller are also mapped to the normal I/O locations. 74 Datasheet R Intel 82810/82810-DC100 (GMCH) ® Figure 6. GMCH Graphics Register Memory Address Space Memory Space Map (512 KB allocation) Offset From Base_Reg 7FFFFh Intel Reserved 30000h 2FFFFh 20000h 1FFFFh Intel Reserved 10000h 0FFFFh 07000h 06FFFh Intel Reserved 04000h 03FFFh Display Cache Interface Control Registers I/O Space Map (Standard graphics locations) 03000h 02FFFh Intel Reserved 01000h 00FFFh VGA and Ext. VGA Registers VGA and Ext. VGA Registers 00000h 31 19 MMADR Register (Base Address) reginstm.vsd • Graphics Controller Graphics Memory Range. The GMCH’s graphics controller device uses a logical memory concept to access graphics memory. The logical graphics memory size is programmable as either 32 MB or 64 MB and is allocated by BIOS during Plug and Play. This address range is programmed in the GMADR Register (Device 1) and the MISCC Register (Device 0). The graphics controller engines can access this address space (the lower 32 MB or all 64 MB correspond to graphics memory that is accessable by the processor). • 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. Processor accesses to the Local APIC configuration space do not result in external bus activity since the Local APIC configuration space is internal to the processor. However, a MTRR must be programmed to make the Local APIC range uncacheable (UC). The Local APIC base address in each processor should be relocated to the FEC0_0000h (4GB–20MB) 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 reside in the I/O Bridge portion of the chipset or as a stand-alone component(s). I/O APIC units are located beginning at the default address FEC0_0000h. The first I/O APIC is 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 address range is normally mapped via hub interface to PCI. The address range between the APIC configuration space and the High BIOS (FED0_0000h to FEDF_FFFFh) is always mapped to PCI (via the hub interface). Datasheet 75 Intel 82810/82810-DC100 (GMCH) ® R • 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. Processor begins execution from the High BIOS after reset. This region is mapped to PCI (via the hub interface) so that the upper subset of this region aliases to 16 MB–256 KB range. The actual address space required for the BIOS is less than 2 MB but the minimum processor MTRR range for this region is 2 MB so that full 2 MB must be considered. The ICH supports a maximum of 1 MB in the High BIOS range. • Optional HSEG. This Extended SMRAM Address Range, if enabled via the SMRAM register, occupies the range from FEEA_0000h to FEEB_FFFFh. Maps to A0000h–BFFFFh when enabled. 4.1.1.3. System Management Mode (SMM) Memory Range The GMCH supports the use of main memory as System Management RAM (SMRAM), enabling the use of System Management Mode. The GMCH supports two SMRAM options: Compatible SMRAM (C_SMRAM) and Extended SMRAM (E_SMRAM). System Management RAM (SMRAM) space provides a memory area that is available for the SMI handler's and code and data storage. This memory resource is normally hidden from the system OS so that the processor has immediate access to this memory space upon entry to SMM. The GMCH provides three SMRAM options: • • • Below 1 MB option that supports compatible SMI handlers. Above 1 MB option that allows new SMI handlers to execute with write-back cacheable SMRAM. Optional larger write-back cacheable T_SEG area of either 512 KB or 1MB in size above 1 MB that is reserved from the highest area in system DRAM memory. The above 1 MB solutions require changes to compatible SMRAM handlers code to properly execute above 1 MB. Refer to the Power Management section for more details on SMRAM support. 4.1.2. Memory Shadowing Any block of memory that can be designated as read-only or write-only can be “shadowed” into the GMCH DRAM memory. Typically, this is done to allow ROM code to execute more rapidly out of main DRAM. ROM is used as a read-only during the copy process while DRAM at the same time is designated write-only. After copying, the DRAM is designated read-only so that ROM is shadowed. Processor bus transactions are routed accordingly. 76 Datasheet R Intel 82810/82810-DC100 (GMCH) ® 4.1.3. I/O Address Space The GMCH does not support the existence of any other I/O devices besides itself on the processor bus. The GMCH generates hub interface bus cycles for all processor I/O accesses that do not target the Legacy I/O registers supported by the internal Graphics Device. The GMCH contains two internal registers in the processor I/O space, Configuration Address Register (CONFIG_ADDRESS) and the Configuration Data Register (CONFIG_DATA). These locations are used to implement PCI configuration space access mechanism as described in the Registers section of this document. The processor allows 64K+3 bytes to be addressed within the I/O space. The GMCH propagates the processor I/O address without any translation to the destination bus and therefore provides addressability for 64K+3 byte locations. Note that the upper 3 locations can be accessed only during I/O address wraparound when processor bus A16# address signal is asserted. A16# is asserted on the processor 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. The I/O accesses, other than ones used for PCI configuration space access or ones that target the internal Graphics Device are forwarded to hub interface. The GMCH does not post I/O write cycles to IDE. The GMCH does not respond to I/O cycles initiated on hub interface. 4.1.4. GMCH Decode Rules and Cross-Bridge Address Mapping The GMCH’s address map applies globally to accesses arriving on any of the three interfaces (i.e., Host bus, hub interface or from the internal Graphics Device). Hub Interface Decode Rules The GMCH accepts all memory Read and Write accesses from hub interface to both System Memory and Graphics Memory. Hub interface accesses that fall elsewhere within the PCI memory range are not accepted. The GMCH does not respond to hub interface-initiated I/O read or write cycles. Legacy VGA Ranges The legacy VGA memory range A0000h–BFFFFh is mapped either to the internal graphics device or to hub interface depending on the programming of the GMS bits in the SMRAM configuration register in GMCH Device #0, and some of the bits in the VGA registers of the internal Graphics Device. These same bits control mapping of VGA I/O address ranges. VGA I/O range is defined as addresses where A[9:0] are in the ranges 3B0h to 3BBh and 3C0h to 3DFh (inclusive of ISA address aliases - A[15:10] are not decoded). These bits control all accesses to the VGA ranges, including support for MDA functionality. I/O accesses to location 3BFh are always forwarded on to hub interface. Datasheet 77 Intel 82810/82810-DC100 (GMCH) ® R 4.2. Host Interface The host interface of the GMCH is optimized to support the Intel® CeleronTM processor. The GMCH implements the host address, control, and data bus interfaces within a single device. The GMCH supports a 4-deep in-order queue (i.e., supports pipelining of up to 4 outstanding transaction requests on the host bus) . Host bus addresses are decoded by the GMCH for accesses to system memory, PCI memory & PCI I/O (via hub interface), PCI configuration space and Graphics memory. The GMCH takes advantage of the pipelined addressing capability of the processor to improve the overall system performance. The GMCH supports the 370-pin socket connector. 4.2.1. Host Bus Device Support The GMCH recognizes and supports a large subset of the transaction types that are defined for the Intel® CeleronTM processor bus interface. However, each of these transaction types have a multitude of response types, some of which are not supported by this controller. All transactions are processed in the order that they are received on the processor bus. 78 Datasheet R Intel 82810/82810-DC100 (GMCH) ® Table 8. Summay of Transactions Supported By GMCH Transaction Deferred Reply Reserved Interrupt Acknowledge Special Transactions Reserved Reserved Branch Trace Message Reserved Reserved Reserved I/O Read REQa[4:0]# 00000 00001 01000 01000 01000 01000 01001 01001 01001 01001 10000 REQb[4:0]# XXXXX XXXXX 00000 00001 0001x 001xx 00000 00001 0001x 001xx 0 0 x LEN# GMCH Support The GMCH initiates a deferred reply for a previously deferred transaction. Reserved Interrupt acknowledge cycles are forwarded to the hub interface. See separate table in special cycles section. Reserved Reserved The GMCH terminates a branch trace message without latching data. Reserved Reserved Reserved I/O read cycles are forwarded to hub interface. I/O cycles that are in the GMCH configuration space are not forwarded to the hub interface. I/O write cycles are forwarded to hub interface. I/O cycles that are in the GMCH configuration space are not forwarded to hub interface. Reserved Host initiated memory read cycles are forwarded to DRAM or the hub interface. Reserved Memory code read cycles are forwarded to DRAM or hub interface. Host initiated memory read cycles are forwarded to DRAM or the hub interface. This memory write is a writeback cycle and cannot be retried. The GMCH forwards the write to DRAM. The standard memory write cycle is forwarded to DRAM or hub interface. I/O Write 10001 0 0 x LEN# Reserved Memory Read & Invalidate Reserved Memory Code Read Memory Data Read Memory Write (no retry) Memory Write (can be retried) 1100x 00010 00011 00100 00110 00101 00111 00xxx 0 0 x LEN# 0 0 x LEN# 0 0 x LEN# 0 0 x LEN# 0 0 x LEN# 0 0 x LEN# NOTES: 1. For Memory cycles, REQa[4:3]# = ASZ#. GMCH only supports ASZ# = 00 (32 bit address). 2. REQb[4:3]# = DSZ#. DSZ# = 00 (64 bit data bus size). 3. LEN# = data transfer length as follows: LEN# Data length 00