915P

R Intel® 915G/915GV/915GL/915P/ 915PL/910GL Express Chipset Datasheet For the Intel® 82915G/82915GV/82915GL/82910GL Graphics and Memory Controller Hub (GMCH) and the Intel® 82915P/82915PL Memory Controller Hub (MCH) February 2005 Document Number: 301467-005 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® 82915G,82915GV,82915GL,82910GL GMCH and 82915P/82915PL MCH 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. Hyper-Threading Technology requires a computer system with an Intel® Pentium® 4 processor supporting HT Technology and a Hyper-Threading Technology enabled chipset, BIOS and operating system. Performance will vary depending on the specific hardware and software you use. See http://www.intel.com/products/ht/hyperthreading_more.htm for more information including details on which processors support HT Technology. Intel, Pentium, Celeron and the Intel logo are trademarks or registered trademarks of Intel Corporation or its subsidiaries in the United States and other countries. *Other names and brands may be claimed as the property of others. Copyright© 2004–2005, Intel Corporation. All rights reserved 1 2 Datasheet R Contents 1 Introduction ....................................................................................................................... 17 1.1 1.2 1.3 Terminology.......................................................................................................... 24 Reference Documents.......................................................................................... 26 GMCH (MCH) Overview....................................................................................... 26 1.3.1 Host Interface........................................................................................ 26 1.3.2 System Memory Interface..................................................................... 27 1.3.3 Direct Media Interface (DMI)................................................................. 28 1.3.4 PCI Express* Graphics Interface (Intel® 82915G/82915P/ and 82915PL Only) ............................................................................... 28 1.3.5 Integrated Graphics (Intel® 82915G/82915GV/82910GL/82915GL GMCH Only) ......................................................................................... 29 1.3.6 Analog and Intel® SDVO Displays (Intel® 82915G/82915GV/82910GL/82915GL GMCH Only) ........................... 31 1.3.7 System Interrupts.................................................................................. 31 1.3.8 (G)MCH Clocking.................................................................................. 31 1.3.9 Power Management.............................................................................. 32 Host Interface Signals .......................................................................................... 35 DDR/DDR2 DRAM Channel A Interface .............................................................. 38 DDR/DDR2 DRAM Channel B Interface .............................................................. 39 DDR/DDR2 DRAM Reference and Compensation .............................................. 40 PCI Express* x16 Graphics Port Signals (Intel® 82915G, 82915P, 82915PL Only)...................................................................................................... 41 Analog Display Signals (Intel® 82915G/82915GV/82915GL/82910GL GMCH Only) ......................................................................................................... 42 Clocks, Reset, and Miscellaneous ....................................................................... 43 Direct Media Interface (DMI) ................................................................................ 43 Intel® Serial DVO (SDVO) Interface (82915G/82915GV/82915GL/82910GL GMCH Only) ......................................................................................................... 44 Power and Ground ............................................................................................... 45 Reset States and Pull-up/Pull-downs................................................................... 46 2 Signal Description ............................................................................................................. 33 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 3 Register Description.......................................................................................................... 53 3.1 3.2 3.3 Register Terminology ........................................................................................... 53 Platform Configuration.......................................................................................... 55 General Routing Configuration Accesses ............................................................ 58 3.3.1 Standard PCI Bus Configuration Mechanism ....................................... 58 3.3.2 Logical PCI Bus 0 Configuration Mechanism ....................................... 58 3.3.3 Primary PCI and Downstream Configuration Mechanism .................... 59 3.3.4 PCI Express* Enhanced Configuration Mechanism ............................. 60 3.3.5 Intel® 915x GMCH Configuration Cycle Flowchart ............................... 62 I/O Mapped Registers .......................................................................................... 63 3.4.1 CONFIG_ADDRESS—Configuration Address Register ...................... 63 3.4 Datasheet 3 R 3.4.2 4 4.1 CONFIG_DATA—Configuration Data Register .................................... 64 Host Bridge/DRAM Controller Registers (D0:F0) ............................................................. 65 Host Bridge/DRAM Controller PCI Register Details (D0:F0) ............................... 68 4.1.1 VID—Vendor Identification (D0:F0) ...................................................... 68 4.1.2 DID—Device Identification (D0:F0) ...................................................... 68 4.1.3 PCICMD—PCI Command (D0:F0) ....................................................... 69 4.1.4 PCISTS—PCI Status (D0:F0)............................................................... 70 4.1.5 RID—Revision Identification (D0:F0).................................................... 71 4.1.6 CC—Class Code (D0:F0) ..................................................................... 71 4.1.7 MLT—Master Latency Timer (D0:F0)................................................... 72 4.1.8 HDR—Header Type (D0:F0) ................................................................ 72 4.1.9 SVID—Subsystem Vendor Identification (D0:F0)................................. 72 4.1.10 SID—Subsystem Identification (D0:F0)................................................ 73 4.1.11 CAPPTR—Capabilities Pointer (D0:F0) ............................................... 73 4.1.12 EPBAR—Egress Port Base Address (D0:F0) ...................................... 74 4.1.13 MCHBAR—(G)MCH Memory Mapped Register Range Base Address (D0:F0).................................................................................................. 75 4.1.14 PCIEXBAR—PCI Express* Register Range Base Address (D0:F0) (Intel® 82915G/82915P/82915PL Only)................................................ 76 4.1.15 DMIBAR—Root Complex Register Range Base Address (D0:F0) ...... 77 4.1.16 GGC—GMCH Graphics Control Register (D0:F0) (82915G/82915GV/82915GL/82910GL GMCH only)........................... 78 4.1.17 DEVEN—Device Enable (D0:F0) ......................................................... 79 4.1.18 PAM0—Programmable Attribute Map 0 (D0:F0) .................................. 81 4.1.19 PAM1—Programmable Attribute Map 1 (D0:F0) .................................. 82 4.1.20 PAM2—Programmable Attribute Map 2 (D0:F0) .................................. 83 4.1.21 PAM3—Programmable Attribute Map 3 (D0:F0) .................................. 84 4.1.22 PAM4—Programmable Attribute Map 4 (D0:F0) .................................. 85 4.1.23 PAM5—Programmable Attribute Map 5 (D0:F0) .................................. 86 4.1.24 PAM6—Programmable Attribute Map 6 (D0:F0) .................................. 87 4.1.25 LAC—Legacy Access Control (D0:F0) ................................................. 88 4.1.26 TOLUD—Top of Low Usable DRAM (D0:F0) ....................................... 89 4.1.27 SMRAM—System Management RAM Control (D0:F0)........................ 90 4.1.28 ESMRAMC—Extended System Management RAM Control (D0:F0) .. 91 4.1.29 ERRSTS—Error Status (D0:F0) ........................................................... 92 4.1.30 ERRCMD—Error Command (D0:F0) ................................................... 93 4.1.31 SKPD—Scratchpad Data (D0:F0) ........................................................ 94 4.1.32 CAPID0—Capability Identifier (D0:F0) ................................................. 94 MCHBAR Register Details ................................................................................... 96 5.1.1 C0DRB0—Channel A DRAM Rank Boundary Address 0 .................... 96 5.1.2 C0DRB1—Channel A DRAM Rank Boundary Address 1 .................... 98 5.1.3 C0DRB2—Channel A DRAM Rank Boundary Address 2 .................... 98 5.1.4 C0DRB3—Channel A DRAM Rank Boundary Address 3 .................... 98 5.1.5 C0DRA0—Channel A DRAM Rank 0,1 Attribute ................................. 99 5.1.6 C0DRA2—Channel A DRAM Rank 2,3 Attribute ................................. 99 5.1.7 C0DCLKDIS—Channel A DRAM Clock Disable ................................ 100 5.1.8 C0BNKARC—Channel A DRAM Bank Architecture .......................... 101 5.1.9 C0DRT1—Channel A DRAM Timing Register ................................... 102 5.1.10 C0DRC0—Channel A DRAM Controller Mode 0 ............................... 104 5.1.11 C1DRB0—Channel B DRAM Rank Boundary Address 0 .................. 106 5 MCHBAR Registers .......................................................................................................... 95 5.1 4 Datasheet R 5.1.12 5.1.13 5.1.14 5.1.15 5.1.16 5.1.17 5.1.18 5.1.19 5.1.20 5.1.21 5.1.22 6 6.1 C1DRB1—Channel B DRAM Rank Boundary Address 1 .................. 106 C1DRB2—Channel B DRAM Rank Boundary Address 2 .................. 106 C1DRB3—Channel B DRAM Rank Boundary Address 3 .................. 106 C1DRA0—Channel B DRAM Rank 0,1 Attribute ............................... 106 C1DRA2—Channel B DRAM Rank 2,3 Attribute ............................... 107 C1DCLKDIS—Channel B DRAM Clock Disable ................................ 107 C1BNKARC—Channel B Bank Architecture ...................................... 107 C1DRT1—Channel B DRAM Timing Register 1 ................................ 107 C1DRC0—Channel B DRAM Controller Mode 0 ............................... 107 PMCFG—Power Management Configuration .................................... 108 PMSTS—Power Management Status ................................................ 108 EPBAR Registers—Egress Port Register Summary ...................................................... 109 EP RCRB Configuration Register Details .......................................................... 109 6.1.1 EPESD—EP Element Self Description............................................... 110 6.1.2 EPLE1D—EP Link Entry 1 Description .............................................. 111 6.1.3 EPLE1A—EP Link Entry 1 Address.................................................... 111 6.1.4 EPLE2D—EP Link Entry 2 Description .............................................. 112 6.1.5 EPLE2A—EP Link Entry 2 Address.................................................... 113 Direct Media Interface (DMI) RCRB Register Details ........................................ 116 7.1.1 DMIVCECH—DMI Virtual Channel Enhanced Capability Header ..... 116 7.1.2 DMIPVCCAP1—DMI Port VC Capability Register 1 .......................... 116 7.1.3 DMIPVCCAP2—DMI Port VC Capability Register 2 .......................... 117 7.1.4 DMIPVCCTL—DMI Port VC Control .................................................. 117 7.1.5 DMIVC0RCAP—DMI VC0 Resource Capability ................................ 118 7.1.6 DMIVC0RCTL0—DMI VC0 Resource Control ................................... 119 7.1.7 DMIVC0RSTS—DMI VC0 Resource Status....................................... 120 7.1.8 DMIVC1RCAP—DMI VC1 Resource Capability ................................ 120 7.1.9 DMIVC1RCTL1—DMI VC1 Resource Control ................................... 121 7.1.10 DMIVC1RSTS—DMI VC1 Resource Status....................................... 121 7.1.11 DMILCAP—DMI Link Capabilities ...................................................... 122 7.1.12 DMILCTL—DMI Link Control .............................................................. 122 7.1.13 DMILSTS—DMI Link Status ............................................................... 123 Host-PCI Express* Bridge PCI Register Details (D1:F0) ................................... 128 8.1.1 VID1—Vendor Identification (D1:F0) .................................................. 128 8.1.2 DID1—Device Identification (D1:F0) .................................................. 128 8.1.3 PCICMD1—PCI Command (D1:F0) ................................................... 129 8.1.4 PCISTS1—PCI Status (D1:F0)........................................................... 130 8.1.5 RID1—Revision Identification (D1:F0)................................................ 132 8.1.6 CC1—Class Code (D1:F0) ................................................................. 132 8.1.7 CL1—Cache Line Size (D1:F0) .......................................................... 133 8.1.8 HDR1—Header Type (D1:F0) ............................................................ 133 8.1.9 PBUSN1—Primary Bus Number (D1:F0) ........................................... 133 8.1.10 SBUSN1—Secondary Bus Number (D1:F0) ...................................... 134 8.1.11 SUBUSN1—Subordinate Bus Number (D1:F0) ................................. 134 8.1.12 IOBASE1—I/O Base Address (D1:F0) ............................................... 135 8.1.13 IOLIMIT1—I/O Limit Address (D1:F0) ................................................ 135 8.1.14 SSTS1—Secondary Status (D1:F0) ................................................... 136 8.1.15 MBASE1—Memory Base Address (D1:F0)........................................ 137 7 DMIBAR Registers—Direct Media Interface (DMI) RCRB ............................................. 115 7.1 8 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) 125 8.1 Datasheet 5 R 8.1.16 8.1.17 8.1.18 8.1.19 8.1.20 8.1.21 8.1.22 8.1.23 8.1.24 8.1.25 8.1.26 8.1.27 8.1.28 8.1.29 8.1.30 8.1.31 8.1.32 8.1.33 8.1.34 8.1.35 8.1.36 8.1.37 8.1.38 8.1.39 8.1.40 8.1.41 8.1.42 8.1.43 8.1.44 8.1.45 8.1.46 8.1.47 8.1.48 8.1.49 8.1.50 8.1.51 8.1.52 8.1.53 8.1.54 8.1.55 8.1.56 8.1.57 8.1.58 8.1.59 9 MLIMIT1—Memory Limit Address (D1:F0)......................................... 138 PMBASE1—Prefetchable Memory Base Address (D1:F0) ................ 139 PMLIMIT1—Prefetchable Memory Limit Address (D1:F0) ................. 140 CAPPTR1—Capabilities Pointer (D1:F0) ........................................... 140 INTRLINE1—Interrupt Line (D1:F0) ................................................... 141 INTRPIN1—Interrupt Pin (D1:F0) ....................................................... 141 BCTRL1—Bridge Control (D1:F0) ...................................................... 142 PM_CAPID1—Power Management Capabilities (D1:F0) .................. 144 PM_CS1—Power Management Control/Status (D1:F0) .................... 145 SS_CAPID—Subsystem ID and Vendor ID Capabilities (D1:F0) ...... 146 SS—Subsystem ID and Subsystem Vendor ID (D1:F0) .................... 146 MSI_CAPID—Message Signaled Interrupts Capability ID (D1:F0).... 147 MC—Message Control (D1:F0) .......................................................... 148 MA—Message Address (D1:F0)......................................................... 149 MD—Message Data (D1:F0) .............................................................. 149 PEG_CAPL—PCI Express* Capability List (D1:F0) ........................... 150 PEG_CAP—PCI Express*-G Capabilities (D1:F0)............................. 150 DCAP—Device Capabilities (D1:F0) .................................................. 151 DCTL—Device Control (D1:F0) .......................................................... 152 DSTS—Device Status (D1:F0) ........................................................... 153 LCAP—Link Capabilities (D1:F0) ....................................................... 154 LCTL—Link Control (D1:F0) ............................................................... 155 LSTS—Link Status (D1:F0) ................................................................ 156 SLOTCAP—Slot Capabilities (D1:F0) ................................................ 157 SLOTCTL—Slot Control (D1:F0) ........................................................ 158 SLOTSTS—Slot Status (D1:F0) ......................................................... 159 RCTL—Root Control (D1:F0) ............................................................. 160 RSTS—Root Status (D1:F0)............................................................... 161 PEGLC—PCI Express*-G Legacy Control ......................................... 162 VCECH—Virtual Channel Enhanced Capability Header (D1:F0) ...... 163 PVCCAP1—Port VC Capability Register 1 (D1:F0) ........................... 163 PVCCAP2—Port VC Capability Register 2 (D1:F0) ........................... 164 PVCCTL—Port VC Control (D1:F0) ................................................... 164 VC0RCAP—VC0 Resource Capability (D1:F0) ................................. 165 VC0RCTL—VC0 Resource Control (D1:F0) ...................................... 165 VC0RSTS—VC0 Resource Status (D1:F0)........................................ 166 VC1RCAP—VC1 Resource Capability (D1:F0) ................................. 166 VC1RCTL—VC1 Resource Control (D1:F0) ...................................... 167 VC1RSTS—VC1 Resource Status (D1:F0)........................................ 168 RCLDECH—Root Complex Link Declaration Enhanced Capability Header (D1:F0) ................................................................................... 168 ESD—Element Self Description (D1:F0) ............................................ 169 LE1D—Link Entry 1 Description (D1:F0)............................................ 170 LE1A—Link Entry 1 Address (D1:F0)................................................. 171 PEGSSTS—PCI Express*-G Sequence Status (D1:F0).................... 171 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only).................................................................................................... 173 9.1 Integrated Graphics Device PCI Register Details (D2:F0)................................. 175 9.1.1 VID2—Vendor Identification (D2:F0) .................................................. 175 9.1.2 DID2—Device Identification (D2:F0) .................................................. 175 9.1.3 PCICMD2—PCI Command (D2:F0) ................................................... 176 9.1.4 PCISTS2—PCI Status (D2:F0)........................................................... 177 6 Datasheet R 9.1.5 9.1.6 9.1.7 9.1.8 9.1.9 9.1.10 9.1.11 9.1.12 9.1.13 9.1.14 9.1.15 9.1.16 9.1.17 9.1.18 9.1.19 9.1.20 9.1.21 9.1.22 9.1.23 9.1.24 9.1.25 9.1.26 9.1.27 9.1.28 9.1.29 9.1.30 9.1.31 9.1.32 9.1.33 10 RID2—Revision Identification (D2:F0)................................................ 178 CC—Class Code (D2:F0) ................................................................... 178 CLS—Cache Line Size (D2:F0).......................................................... 179 MLT2—Master Latency Timer (D2:F0)............................................... 179 HDR2—Header Type (D2:F0) ............................................................ 180 MMADR—Memory Mapped Range Address (D2:F0) ........................ 180 IOBAR—I/O Base Address (D2:F0) ................................................... 181 GMADR—Graphics Memory Range Address (D2:F0) ....................... 182 GTTADR—Graphics Translation Table Range Address (D2:F0)....... 183 SVID2—Subsystem Vendor Identification (D2:F0)............................. 183 SID2—Subsystem Identification (D2:F0)............................................ 184 ROMADR—Video BIOS ROM Base Address (D2:F0) ....................... 184 CAPPOINT—Capabilities Pointer (D2:F0) ......................................... 185 INTRLINE—Interrupt Line (D2:F0) ..................................................... 185 INTRPIN—Interrupt Pin (D2:F0) ......................................................... 185 MINGNT—Minimum Grant (D2:F0) .................................................... 186 MAXLAT—Maximum Latency (D2:F0) ............................................... 186 MCAPPTR—Mirror of Dev0 Capability Pointer (D2:F0) (Mirrored_D0_34) ............................................................................... 186 MCAPID—Mirror of Dev0 Capability Identification (D2:F0) (Mirrored_D0_E0) ............................................................................... 186 MGGC—Mirror of Dev0 GMCH Graphics Control (D2:F0) (Mirrored_D0_52) ............................................................................... 187 MDEVENdev0f0—Mirror of Dev0 Device Enable (D2:F0) (Mirrored_D0_54) ............................................................................... 187 BSM—Base of Stolen Memory (D2:F0).............................................. 187 MSAC—Multi Size Aperture Control (D2:F0) ..................................... 188 PMCAPID—Power Management Capabilities ID (D2:F0).................. 188 PMCAP—Power Management Capabilities (D2:F0) .......................... 189 PMCS—Power Management Control/Status (D2:F0) ........................ 190 SWSMI—Software SMI (D2:F0) ......................................................... 191 ASLE—System Display Event Register (D2:F0) ................................ 191 ASLS—ASL Storage (D2:F0) ............................................................. 192 Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only)................................................................. 193 10.1 Device 2 Function 1 Configuration Register Details (D2:F1) ............................. 194 10.1.1 VID2—Vendor Identification (D2:F1) .................................................. 194 10.1.2 DID2—Device Identification (D2:F1) .................................................. 194 10.1.3 PCICMD2—PCI Command (D2:F1) ................................................... 195 10.1.4 PCISTS2—PCI Status (D2:F1)........................................................... 196 10.1.5 RID2—Revision Identification (D2:F1)................................................ 197 10.1.6 CC—Class Code Register (D2:F1)..................................................... 197 10.1.7 CLS—Cache Line Size (D2:F1).......................................................... 197 10.1.8 MLT2—Master Latency Timer (D2:F1)............................................... 198 10.1.9 HDR2—Header Type Register (D2:F1).............................................. 198 10.1.10 MMADR—Memory Mapped Range Address (D2:F1) ........................ 198 10.1.11 SVID2—Subsystem Vendor Identification (D2:F1)............................. 199 10.1.12 SID2—Subsystem Identification (D2:F1)............................................ 199 10.1.13 ROMADR—Video BIOS ROM Base Address (D2:F1) ....................... 199 10.1.14 CAPPOINT—Capabilities Pointer (D2:F1) ......................................... 199 10.1.15 MINGNT—Minimum Grant Register (D2:F1)...................................... 200 10.1.16 MAXLAT—Maximum Latency (D2:F1) ............................................... 200 Datasheet 7 R 10.2 10.1.17 MCAPPTR—Mirror of Dev0 Capability Pointer (D2:F1) (Mirrored_D0_34) ............................................................................... 200 10.1.18 MCAPID—Mirror of Dev0 Capability Identification (D2:F1) (Mirrored_D0_E0) ............................................................................... 200 10.1.19 MGGC—Mirror of Dev0 GMCH Graphics Control (D2:F1) (Mirrored_D0_52) ............................................................................... 200 10.1.20 MDEVENdev0f0—Mirror of Dev0 Device Enable (D2:F1) (Mirrored_D0_54) ............................................................................... 201 10.1.21 BSM—Base of Stolen Memory Register (D2:F1) ............................... 201 10.1.22 PMCAPID—Power Management Capabilities ID (D2:F1).................. 201 10.1.23 PMCAP—Power Management Capabilities (D2:F1) .......................... 201 10.1.24 PMCS—Power Management Control/Status (D2:F1) ........................ 202 10.1.25 SWSMI—Software SMI (D2:F1) ......................................................... 202 10.1.26 ASLS—ASL Storage (D2:F1) ............................................................. 203 Device 2 – PCI I/O Registers ............................................................................. 204 10.2.1 MMIO_INDEX—MMIO Address Register........................................... 204 10.2.2 MMIO_DATA—MMIO Data Register .................................................. 204 Legacy Address Range ...................................................................................... 207 11.1.1 DOS Range (0h – 9_FFFFh) .............................................................. 208 11.1.2 Legacy Video Area (A_0000h–B_FFFFh) .......................................... 208 11.1.3 Expansion Area (C_0000h–D_FFFFh)............................................... 209 11.1.4 Extended System BIOS Area (E_0000h–E_FFFFh) .......................... 210 11.1.5 System BIOS Area (F_0000h–F_FFFFh)........................................... 210 11.1.6 Programmable Attribute Map (PAM) Memory Area Details................ 210 Main Memory Address Range (1 MB to TOLUD) .............................................. 211 11.2.1 ISA Hole (15 MB–16 MB) ................................................................... 211 11.2.2 TSEG .................................................................................................. 212 11.2.3 Pre-allocated Memory......................................................................... 212 PCI Memory Address Range (TOLUD – 4 GB) ................................................. 212 11.3.1 APIC Configuration Space (FEC0_0000h-FECF_FFFFh) ................. 214 11.3.2 HSEG (FEDA_0000h–FEDB_FFFFh) ................................................ 214 11.3.3 FSB Interrupt Memory Space (FEE0_0000–FEEF_FFFF) ................ 214 11.3.4 High BIOS Area .................................................................................. 214 11.3.5 PCI Express* Configuration Address Space (Intel® 82915G/82915P Only) ................................................................................................... 215 11.3.6 PCI Express* Graphics Attach (Intel® 82915G/82915P Only)............ 215 11.3.7 AGP DRAM Graphics Aperture .......................................................... 215 11.3.8 Graphics Memory Address Ranges (Intel® 82915G/82915GV/82915GL/82910GL GMCH Only) ......................... 216 System Management Mode (SMM) ................................................................... 216 11.4.1 SMM Space Definition ........................................................................ 217 11.4.2 SMM Space Restrictions .................................................................... 217 11.4.3 SMM Space Combinations ................................................................. 218 11.4.4 SMM Control Combinations................................................................ 218 11.4.5 SMM Space Decode and Transaction Handling ................................ 219 11.4.6 Processor WB Transaction to an Enabled SMM Address Space ...... 219 11.4.7 SMM Access through GTT TLB (Intel® 82915G/82915GV/82910GL GMCH Only) ....................................................................................... 219 11.4.8 Memory Shadowing ............................................................................ 219 11.4.9 I/O Address Space.............................................................................. 220 11 System Address Map ...................................................................................................... 205 11.1 11.2 11.3 11.4 8 Datasheet R 11.4.10 PCI Express* I/O Address Mapping (Intel® 82915G/82915P/82915PL Only) ................................................................................................... 220 11.4.11 (G)MCH Decode Rules and Cross-Bridge Address Mapping ............ 220 11.4.12 Legacy VGA and I/O Range Decode Rules ....................................... 221 12 Functional Description .................................................................................................... 223 12.1 Host Interface ..................................................................................................... 223 12.1.1 FSB GTL+ Termination....................................................................... 223 12.1.2 FSB Dynamic Bus Inversion ............................................................... 223 12.1.3 APIC Cluster Mode Support ............................................................... 224 System Memory Controller................................................................................. 224 12.2.1 Memory Organization Modes.............................................................. 224 System Memory Configuration Registers Overview .......................................... 226 12.3.1 DRAM Technologies and Organization .............................................. 227 12.3.1.1 Rules for Populating DIMM Slots ...................................... 227 12.3.1.2 System Memory Supported Configurations ...................... 228 12.3.1.3 Main Memory DRAM Address Translation and Decoding 228 12.3.2 DRAM Clock Generation .................................................................... 231 12.3.3 Suspend-to-RAM and Resume........................................................... 231 12.3.4 DDR2 On-Die Termination.................................................................. 231 12.3.5 DDR2 Off-Chip Driver Impedance Calibration.................................... 231 PCI Express* (Intel® 82915G/82915P82915PL Only)........................................ 232 12.4.1 Transaction Layer ............................................................................... 232 12.4.2 Data Link Layer................................................................................... 232 12.4.3 Physical Layer..................................................................................... 232 Intel® Serial Digital Video Output (SDVO) (Intel® 82915G/82915GV/82915GL/82910GL GMCH Only)......................................... 233 12.5.1 Intel® SDVO Capabilities..................................................................... 233 12.5.2 Intel® SDVO Modes ............................................................................ 234 Integrated Graphics Device (Intel® 82915G/82915GV/82915GL/82910GL GMCH Only) ....................................................................................................... 235 12.6.1 3D Engine ........................................................................................... 236 12.6.2 Setup Engine ...................................................................................... 236 12.6.2.1 3D Primitives and Data Formats Support.......................... 236 12.6.2.2 Pixel Accurate “Fast” Scissoring and Clipping Operation . 237 12.6.2.3 Depth Bias ......................................................................... 237 12.6.2.4 Backface Culling................................................................ 237 12.6.2.5 Scan Converter.................................................................. 237 12.6.2.6 Pixel Rasterization Rules .................................................. 237 12.6.2.7 2D Functionality................................................................. 237 12.6.3 Texture Engine.................................................................................... 238 12.6.3.1 Perspective Correct Texture Support................................ 238 12.6.3.2 Texture Formats and Storage ........................................... 238 12.6.3.3 Texture Decompression .................................................... 238 12.6.3.4 Texture ChromaKey .......................................................... 238 12.6.3.5 Anti-Aliasing....................................................................... 238 12.6.3.6 Texture Map Filtering ........................................................ 238 12.6.3.7 Multiple Texture Composition............................................ 239 12.6.3.8 Bi-Cubic Filter (4x4 Programmable Texture Filter) ........... 239 12.6.3.9 Cubic Environment Mapping ............................................. 240 12.6.4 Raster Engine ..................................................................................... 240 12.6.4.1 Texture Map Blending ....................................................... 240 12.2 12.3 12.4 12.5 12.6 Datasheet 9 R 12.7 12.8 12.9 13 Combining Intrinsic and Specular Color Components ...... 240 Color Shading Modes........................................................ 240 Color Dithering................................................................... 241 Vertex and Per Pixel Fogging............................................ 241 Alpha Blending (Frame Buffer).......................................... 241 Microsoft DirectX* API and SGI OpenGL* API Logic Ops 242 Color Buffer Formats: 8-, 16-, or 32-bits per Pixel (Destination Alpha) ............................................................ 242 12.6.4.9 Depth Buffer ...................................................................... 242 12.6.4.10 Stencil Buffer ..................................................................... 243 12.6.4.11 Projective Textures............................................................ 243 12.6.5 2D Engine ........................................................................................... 243 12.6.5.1 GMCH VGA Registers....................................................... 243 12.6.5.2 Logical 128-bit Fixed BLT and 256 Fill Engine.................. 243 12.6.6 Video Engine....................................................................................... 244 12.6.6.1 Hardware Motion Compensation....................................... 244 12.6.6.2 Sub-Picture Support .......................................................... 244 12.6.7 Planes ................................................................................................. 245 12.6.7.1 Cursor Plane...................................................................... 245 12.6.7.2 Overlay Plane .................................................................... 245 12.6.7.3 Advanced Deinterlacing and Dynamic Bob and Weave ... 246 12.6.8 Pipes ................................................................................................... 246 12.6.8.1 Clock Generator Units (DPLL) .......................................... 246 Display Interfaces (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only)247 12.7.1 Analog Display Port Characteristics ................................................... 249 12.7.1.1 Integrated RAMDAC.......................................................... 249 12.7.1.2 Sync Signals...................................................................... 249 12.7.1.3 VESA/VGA Mode .............................................................. 249 12.7.1.4 DDC (Display Data Channel) ............................................ 250 12.7.2 Digital Display Interface ...................................................................... 250 12.7.2.1 Digital Display Channels – SDVOB and SDVOC.............. 250 12.7.2.2 ADD2 Card ........................................................................ 250 12.7.3 Multiple Display Configurations .......................................................... 252 Power Management ........................................................................................... 253 Clocking.............................................................................................................. 253 12.6.4.2 12.6.4.3 12.6.4.4 12.6.4.5 12.6.4.6 12.6.4.7 12.6.4.8 Electrical Characteristics................................................................................................. 255 13.1 13.2 13.3 13.4 Absolute Maximum Ratings................................................................................ 255 Power Characteristics ........................................................................................ 257 Signal Groups..................................................................................................... 259 DC Characteristics ............................................................................................. 262 13.4.1 General DC Characteristics ................................................................ 262 13.4.2 RGB/CRT DAC Display DC Characteristics (Intel® 82915G/82915GV/82915GL/82910GL GMCH Only) ......................... 265 DDR2 Ballout...................................................................................................... 267 DDR Ballout........................................................................................................ 329 Package Information .......................................................................................... 395 14 Ballout and Package Information .................................................................................... 267 14.1 14.2 14.3 15 Testability ........................................................................................................................ 399 15.1 Complimentary Pins ........................................................................................... 399 10 Datasheet R 15.2 15.3 15.4 15.5 15.6 15.7 XOR Test Mode Initialization for DDR................................................................ 400 XOR Test Mode Initialization for DDR2.............................................................. 400 XOR Chain Definition ......................................................................................... 401 DDR XOR Chains............................................................................................... 401 DDR2 XOR Chains............................................................................................. 414 PADs Excluded from XOR Mode(s) ................................................................... 426 Figures Figure 1-1. Intel® 915G Express Chipset System Block Diagram Example ..................... 18 Figure 1-2. Intel® 915P Express Chipset System Block Diagram Example ..................... 19 Figure 1-3. Intel® 915GV Express Chipset System Block Diagram Example................... 20 Figure 1-4. Intel® 910GL Express Chipset System Block Diagram Example ................... 21 Figure 1-5. Intel® 915PL Express Chipset System Block Diagram Example ................... 22 Figure 1-6. Intel® 915GL Express Chipset System Block Diagram Example ................... 23 Figure 2-1. Intel® (G)MCH Signal Interface Diagram........................................................ 34 Figure 3-1. Conceptual Chipset PCI Configuration Diagram............................................ 55 Figure 3-2. Register Organization (Representative of the Intel® 82915G GMCH) ........... 57 Figure 3-3. DMI Type 0 Configuration Address Translation ............................................. 59 Figure 3-4. DMI Type 1 Configuration Address Translation ............................................. 59 Figure 3-5. Memory Map to PCI Express* Device Configuration Space .......................... 60 Figure 3-6. Intel® 915x GMCH Configuration Cycle Flowchart......................................... 62 Figure 6-1. Link Declaration Topology............................................................................ 109 Figure 11-1. System Address Ranges............................................................................ 207 Figure 11-2. Microsoft MS-DOS* Legacy Address Range ............................................. 208 Figure 11-3. Main Memory Address Range.................................................................... 211 Figure 11-4. PCI Memory Address Range...................................................................... 213 Figure 12-1. System Memory Styles............................................................................... 225 Figure 12-2. Integrated Graphics Device Block Diagram ............................................... 235 Figure 12-3. System Clocking Example.......................................................................... 254 Figure 14-1. Intel® 82915G GMCH Ballout for DDR2 (Top View: Columns 1–12) ......... 268 Figure 14-2. Intel® 82915G GMCH Ballout for DDR2 (Top View: Columns 13–24) ....... 269 Figure 14-3. Intel® 82915G GMCH Ballout for DDR2 (Top View: Columns 25–35) ....... 270 Figure 14-4. Intel® 82915G GMCH Ballout for DDR (Top View: Columns 1–12 ) .......... 330 Figure 14-5. Intel® 82915G GMCH Ballout for DDR (Top View: Columns 13–24 ) ........ 331 Figure 14-6. Intel® 82915G GMCH Ballout for DDR (Top View: Columns 25–35 ) ........ 332 Figure 14-7. (G)MCH Package Dimensions ................................................................... 396 Figure 14-8. (G)MCH Component Keep-Out Restrictions .............................................. 397 Figure 15-1. XOR Test Mode Initialization Cycles .......................................................... 400 Datasheet 11 R Tables Table 2-1. Host Interface Reset and S3 States ................................................................ 46 Table 2-2. System Memory (DDR2) Reset and S3 States ............................................... 47 Table 2-3. System Memory (DDR) Reset and S3 States ................................................. 49 Table 2-4. PCI Express* Graphics x16 Port Reset and S3 States ................................... 50 Table 2-5. DMI Reset and S3 States ................................................................................ 50 Table 2-6. Clocking Reset and S3 States......................................................................... 51 Table 2-7. MISC Reset and S3 States.............................................................................. 51 Table 2-8. DAC Reset and S3 States (Intel® 82915G/82915GV/82915GL/82910GL GMCH only) ............................................................................................................... 51 Table 3-1. Device Number Assignment for Internal (G)MCH Devices ............................. 57 Table 4-1. Device 0 Function 0 Register Address Map Summary.................................... 65 Table 6-1. Egress Port Register Address Map ............................................................... 109 Table 7-1. DMI Register Address Map Summary ........................................................... 115 Table 8-1. Host-PCI Express* Graphics Bridge Register Address Map (D1:F0) ........... 125 Table 9-1. Integrated Graphics Device Register Address Map (D2:F0)......................... 173 Table 10-1. Device 2 Function 1 Register Address Map Summary ............................... 193 Table 11-1. Expansion Area Memory Segments ............................................................ 209 Table 11-2. Extended System BIOS Area Memory Segments....................................... 210 Table 11-3. System BIOS Area Memory Segments ....................................................... 210 Table 11-4. Pre-Allocated Memory Example for 64-MB DRAM, 1-MB VGA and 1-MB TSEG ....................................................................................................................... 212 Table 11-5. SMM Space Table ....................................................................................... 218 Table 11-6. SMM Control Table...................................................................................... 218 Table 12-1. Sample System Memory Organization with Interleaved Channels ............. 225 Table 12-2. Sample System Memory Organization with Asymmetric Channels ............ 225 Table 12-3. DDR / DDR2 DIMM Supported Configurations ........................................... 228 Table 12-4. DRAM Address Translation (Single Channel/Dual Asymmetric Mode) ...... 229 Table 12-5. DRAM Address Translation (Dual Channel Symmetric Mode) ................... 230 Table 12-6. Display Port Characteristics ........................................................................ 248 Table 12-7. Analog Port Characteristics ......................................................................... 249 Table 13-1. Absolute Maximum Ratings ......................................................................... 255 Table 13-2. Non-Memory Power Characteristics............................................................ 257 Table 13-3. DDR Power Characteristics......................................................................... 258 Table 13-4. DDR2 Power Characteristics....................................................................... 258 Table 13-5. Signal Groups .............................................................................................. 259 Table 13-6. DC Characteristics3 ..................................................................................... 262 Table 13-7. RGB/CRT DAC Display DC Characteristics (Functional Operating Range: VCCA_DAC = 2.5 V ±5%) ....................................................................................... 265 Table 14-1. GMCH/MCH Ballout for DDR2 Systems (Sorted by Ball Number).............. 271 Table 14-2. GMCH/MCH Ballout for DDR2 Systems (Sorted by Signal Name)............. 300 Table 14-3. GMCH/MCH Ballout for DDR Systems (Sorted by Ball Number)................ 333 Table 14-4. GMCH/MCH Ballout for DDR Systems (Sorted by Signal Name)............... 365 Table 15-1. Complimentary Pins to Drive ....................................................................... 399 Table 15-2. XOR Chain Outputs for both DDR and DDR2............................................. 401 Table 15-3. DDR XOR Chain #0..................................................................................... 402 Table 15-4. DDR XOR Chain #1..................................................................................... 404 Table 15-5. DDR XOR Chain #2..................................................................................... 406 Table 15-6. DDR XOR Chain #3..................................................................................... 407 Table 15-7. DDR XOR Chain #4..................................................................................... 408 Table 15-8. DDR XOR Chain #5..................................................................................... 409 Table 15-9. DDR XOR Chain #6..................................................................................... 410 12 Datasheet R Table 15-10. DDR XOR Chain #7................................................................................... 411 Table 15-11. DDR XOR Chain #8................................................................................... 412 Table 15-12. DDR XOR Chain #9................................................................................... 413 Table 15-13. DDR2 XOR Chain #0................................................................................. 414 Table 15-14. DDR2 XOR Chain #1................................................................................. 416 Table 15-15. DDR2 XOR Chain #2................................................................................. 418 Table 15-16. DDR2 XOR Chain #3................................................................................. 419 Table 15-17. DDR2 XOR Chain #4................................................................................. 420 Table 15-18. DDR2 XOR Chain #5................................................................................. 421 Table 15-19. DDR2 XOR Chain #6................................................................................. 422 Table 15-20. DDR2 XOR Chain #7................................................................................. 423 Table 15-21. DDR2 XOR Chain #8................................................................................. 424 Table 15-22. DDR2 XOR Chain #9................................................................................. 425 Table 15-23. XOR Pad Exclusion List............................................................................. 426 Datasheet 13 R Revision History Rev -001 -002 Description • Initial Release • Added Intel 82915GV GMCH ® Date June 2004 September 2004 • Minor edits throughout for clarity -003 -004 • Added Intel 82910GL GMCH ® September 2004 January 2005 • Added Intel 82915GL GMCH ® ® • Added Intel 82915PL GMCH -005 • Minor edits throughout for clarity February 2005 14 Datasheet R Intel® 82915G/82915GV/82915GL/ 82910GL/82915P/82915PL (G)MCH Features Processor Interface ⎯ One Intel® Pentium® 4 processor or Intel® Celeron® D processor including 775-Land package. ⎯ Supports Pentium 4 processor FSB interrupt delivery ⎯ 533 MT/s (133 MHz) FSB (82915G/82915GV/ 82915GL/82910GL/82915P/82915PL) and 800 MT/s (200 MHz) FSB (82915G/82915GV/ 82915GL/82915P/82915PL only) ⎯ FSB Dynamic Bus Inversion (DBI) ⎯ 32-bit host bus addressing for access to 4 GB of memory space ⎯ 12-deep In-Order Queue ⎯ 1-deep Defer Queue ⎯ GTL+ bus driver with integrated GTL termination resistors ⎯ Supports a Cache Line Size of 64 bytes System Memory ⎯ One or two 64-bit wide DDR/DDR2 SDRAM data channels (82915PL and 82910GL supports DDR 400 or DDR 333, 1 DIMM, 2 Channels only) (82915PL supports DDR only) ⎯ Bandwidth up to 8.5 GB/s (DDR/DDR2 533) in dual-channel interleaved mode. ⎯ Non-ECC memory only. ⎯ 256-Mb, 512-Mb and 1-Gb DDR/DDR2 technologies ⎯ Only x8, x16, DDR/DDR2 devices with four banks and also supports eight bank, 1-Gbit DDR2 devices. ⎯ Opportunistic refresh ⎯ Up to 64 simultaneously open pages (four ranks of eight bank devices* 2 channels) ⎯ SPD (Serial Presence Detect) scheme for DIMM detection support ⎯ Suspend-to-RAM support using CKE ⎯ Supports configurations defined in the JEDEC DDR/DDR2 DIMM specification only PCI Express* Graphics Interface (82915G/82915P/82915PL only) ⎯ One x16 PCI Express port ⎯ Compatible with the PCI Express Base Specification revision 1.0a Integrated Graphics Device (82915G/82915GV/82915GL/82910GL only) ⎯ Core frequency of 333 MHz ⎯ High-Quality 3D Setup and Render Engine ⎯ High-Quality Texture Engine ⎯ Video DVD/PC-VCR ⎯ 3D Graphics Rendering Enhancements ⎯ 2D Graphics ⎯ Video Overlay ⎯ Multiple Overlay Functionality Analog Display Support (82915G/82915GV/82915GL/82910GL only) ⎯ 400 MHz Integrated 24-bit RAMDAC ⎯ Up to 2048x1536@ 85 Hz refresh ⎯ Hardware Color Cursor Support ⎯ DDC2B Compliant Interface Digital Display Support (82915G/82915GV/82915GL/82910GL only) ⎯ Two SDVO ports multiplexed with PCI Express Graphics Interface (82915G only) ⎯ 200 MHz dot clock on each 12-bit interface ⎯ Can combine two channels to form one larger interface (82915G only) ⎯ Flat panels up to 2048x1536@ 85Hz or digital CRT/HDTV at 1920x1080@ 85Hz ⎯ Dual Independent Display options with digital display. (82915G only) ⎯ Multiplexed Digital Display Channels (Supported with ADD2 Card). (82915G only) ⎯ Supports TMDS transmitters or TV-Out encoders ⎯ ADD2 card uses PCI Express Graphics x16 connector (82915G only) DMI Interface ⎯ A chip-to-chip connection interface to Intel® ICH6 ⎯ 2 GB/s point-to-point DMI to ICH6 (1 GB/s each direction) ⎯ 100 MHz reference clock (shared with PCI Express Graphics Attach). ⎯ 32-bit downstream addressing ⎯ Messaging and Error Handling Package ⎯ 37.5 mm × 37.5 mm., 1210 balls, variable ball pitch Datasheet 15 R 16 Datasheet Introduction R 1 Introduction The Intel® 91x Express chipset family is designed for use with the Intel® Pentium® 4 processor / Intel® Celeron® D processor (Intel® 915G/915GV/915GL/915P/915PL chipsets) or Intel® Celeron® processor (Intel® 910GL chipset) in desktop platforms. Each chipset in the family contains two components: GMCH (or MCH) for the host bridge and I/O Controller Hub 6 (ICH6) for the I/O subsystem. The 82915G GMCH is part of the 915G Express chipset, the 82915GV is part of the 915GV Express chipset, the 82915GL is part of the 915GL Express Chipset, the 82910GL is part of the 910GL Express chipset, the 82915P MCH is part of the 915P Express chipset, and the 82915PL is part of the 915PL Express chipset. The ICH6 is the sixth generation I/O Controller Hub and provides a multitude of I/O related functions. Figure 1-1 shows an example system block diagram for the 915G Express chipset, Figure 1-2 shows an example system block diagram for the 915P Express chipsets, Figure 1-3 shows an example system block diagram for the 915GV Express chipset, Figure 1-4 shows an example system block diagram for the 910GL Express chipsets, Figure 1-5 shows an example system block diagram for the 915PL Express chipsets, and Figure 1-6 shows an example system block diagram for the 915GL Express chipsets. This document is the datasheet for the Intel® 82915G Graphics and Memory Controller Hub (GMCH), Intel® 82915GV Graphics and Memory Controller Hub (GMCH), Intel® 82915GL Graphics and Memory Controller Hub (GMCH), Intel® 82910GL Graphics and Memory Controller Hub (GMCH), Intel® 82915P Memory Controller Hub (MCH), and the Intel® 82915PL Memory Controller Hub (MCH). Topics covered include; signal description, system memory map, PCI register description, a description of the (G)MCH interfaces and major functional units, electrical characteristics, ballout definitions, and package characteristics. The difference between the 82915G GMCH and 82915P MCH is that the 82915G GMCH contains an integrated graphics port (and associated SDVO and analog display ports) and the 82915P MCH does not contain these items. Both devices support PCI Express graphics. The 82915GV GMCH contains an integrated graphics port (and associated SDVO and analog display ports), but does not support PCI Express graphics. The 82915GL GMCH has the same features as the 82915GV GMCH, but only supports DDR memory. The 82915PL GMCH has the same features as the 82915P GMCH, but only supports 2 channels of DDR DIMM memory to a maximum of 1-DIMM per channel. The 82910GL GMCH supports only 533 MHz FSB, contains an integrated graphics port (and associated SDVO and analog display ports), does not support PCI Express graphics, and supports only 2 channels of DDR DIMM memory to a maximum of 1DIMM per channel. Note: Unless otherwise specified, the information in this document applies to the 82915G Graphics and Memory Controller Hub (GMCH), 82915GV Graphics and Memory Controller Hub (GMCH), 82915GV Graphics and Memory Controller Hub (GMCH), 82910GL Graphics and Memory Controller Hub (GMCH), 82915PL Memory Controller Hub (MCH), and the 82915P Memory Controller Hub (MCH). Note: References in this document to PCI Express are for the 82915G, 82915P, and the 82915PL only. Note: References in this document to the Integrated Graphics Device (IGD) are for the 82915G, 82915GV, 82915GL, and 82910GL only. Datasheet 17 Introduction R Note: References in this document to DDR2 memory are for the 82915G, 82915GV, and 82915P only. Note: Unless otherwise specified, ICH6 refers to the Intel® 82801FB ICH6, 82801FR ICHR, 82801FW ICH6W, and 82801FRW ICH6RW I/O Controller Hub 6 components. Figure 1-1. Intel® 915G Express Chipset System Block Diagram Example Intel® Pentium® 4 Processor or Intel® Celeron® D Processor 533/800 MHz FSB Intel® 915G Express Chipset Analog Display VGA System Memory DDR or DDR2 Intel® 82915G GMCH Channel A DDR or DDR2 Display Add2 Card SDVO Display OR Graphics Card PCI Express x16 Graphics Channel B DDR or DDR2 Display DDR or DDR2 DMI Interface USB 2.0 8 ports, 480 Mb/s Power Management Clock Generation GPIO LAN Connect/ASF 4 Serial ATA Ports 150 MB/s Intel ICH6 ® System Management (TCO) SMBus 2.0/I2C Seven PCI Masters 2 ATA 100 Ports AC '97 3 CODEC support PCI Bus Flash BIOS LPC Interface SIO Sys_Blk_G 18 Datasheet Introduction R Figure 1-2. Intel® 915P Express Chipset System Block Diagram Example Intel® Pentium® 4 Processor or Intel® Celeron® D Processor 533/800 MHz FSB Intel® 915P Express Chipset System Memory DDR or DDR2 Channel A Display Graphics Card PCI Express x16 Graphics Intel® 82915P MCH DDR or DDR2 Channel B DDR or DDR2 DDR or DDR2 DMI Interface USB 2.0 8 ports, 480 Mb/s IDE 4 SATA Ports 150 MB/s Intel® ICH6x AC '97/Intel® High Definition Audio CODECs PCI Express* x1 Intel® PCI Express Gigabit Ethernet GPIO Seven PCI Masters PCI Bus System Management (TCO) SMBus 2.0/I2C Power Management Clock Generation LAN Connect/ASF Flash BIOS LPC Interface SIO Sys_Blk_P Datasheet 19 Introduction R Figure 1-3. Intel® 915GV Express Chipset System Block Diagram Example Intel® Pentium ® 4 Processor or Intel® Celeron® D Processor 533/800 MHz System Bus Analog Display Intel® 915GV Express Chipset VGA System Memory DDR or DDR2 Channel A Intel® 82915GV GMCH DDR or DDR2 Display Add2 Card SDVO Display Channel B DDR or DDR2 DDR or DDR2 DMI Interface USB 2.0 8 ports, 480 Mb/s Power Management Clock Generation GPIO LAN Connect/ASF 4 Serial ATA Ports 150 MB/s Intel® ICH6 System Management (TCO) SMBus 2.0/I2C Seven PCI Masters AC '97 3 CODEC support PCI Bus 2 ATA 100 Ports Flash BIOS LPC Interface SIO Sys_Blk_GV 20 Datasheet Introduction R Figure 1-4. Intel® 910GL Express Chipset System Block Diagram Example Intel® Celeron® D Processor 533 MHz System Bus Analog Display Intel® 910GL Express Chipset System Memory VGA Channel A Display Add2 Card SDVO Intel® 82910GL GMCH Channel B DDR Display DDR DMI Interface USB 2.0 8 ports, 480 Mb/s Power Management Clock Generation GPIO LAN Connect/ASF 4 Serial ATA Ports 150 MB/s Intel® ICH6 System Management (TCO) SMBus 2.0/I2C Seven PCI Masters AC '97 3 CODEC support PCI Bus 2 ATA 100 Ports Flash BIOS LPC Interface SIO Sys_Blk_GL Datasheet 21 Introduction R Figure 1-5. Intel® 915PL Express Chipset System Block Diagram Example Intel® Pentium ® 4 Processor or Intel® Celeron® D Processor 533/800 MHz FSB Intel® 915PL Express Chipset System Memory Channel A Display Graphics Card PCI Express* x16 Graphics Intel ® DDR 82915PL MCH Channel B DDR DMI Interface USB 2.0 8 ports, 480 Mb/s IDE 4 SATA Ports 150 MB/s Intel® ICH6x AC '97/Intel® High Definition Audio CODECs PCI Express* x1 Intel® PCI Express Gigabit Ethernet GPIO Seven PCI Masters PCI Bus System Management (TCO) SMBus 2.0/I2C Power Management Clock Generation LAN Connect/ASF Flash BIOS LPC Interface SIO Sys_Blk_P 22 Datasheet Introduction R Figure 1-6. Intel® 915GL Express Chipset System Block Diagram Example Intel® Pentium® 4 Processor or Intel® Celeron® D Processor 533/800 MHz System Bus Analog Display Intel® 915GL Express Chipset VGA System Memory DDR Channel A Intel® 82915GL GMCH DDR Display Add2 Card SDVO Display Channel B DDR DDR DMI Interface USB 2.0 8 ports, 480 Mb/s Power Management Clock Generation GPIO LAN Connect/ASF 4 Serial ATA Ports 150 MB/s Intel® ICH6 System Management (TCO) SMBus 2.0/I2C Seven PCI Masters AC '97 3 CODEC support PCI Bus 2 ATA 100 Ports Flash BIOS LPC Interface SIO Sys_Blk_GV Datasheet 23 Introduction R 1.1 Terminology Term ADD2 Card nd Description Advanced Digital Display Card – 2 Generation. Provides digital display options for an Intel graphics controller that supports ADD2 cards. This card plugs into a x16 PCI Express connector but uses the multiplexed SDVO interface. Will not work with an Intel graphics controller that supports DVO and ADD cards. Core refers to the internal base logic in the (G)MCH. Cathode Ray Tube. Dynamic Bus Inversion. Double Data Rate SDRAM memory technology. A second generation Double Data Rate SDRAM memory technology. The Direct Media Interface is the connection between the (G)MCH and the Intel ICH6. Digital Video Interface. This is the specification that defines the connector and interface for digital displays. Front Side Bus. The FSB is synonymous with Host or processor bus Full reset is when PWROK is de-asserted. Warm reset is when both RSTIN# and PWROK are asserted. Graphics Memory Controller Hub component that contains the processor interface, DRAM controller, and integrated graphics device. It may also contain an x16 PCI Express port (typically the external graphics interface). It communicates with the I/O controller hub (ICH6*) over the DMI interconnect. Throughout this document GMCH ® refers to the Intel 82915G GMCH, 82915GV GMCH, 82915GL, and 82910GL, unless otherwise specified. Note that term (G)MCH is used when referring to both GMCH and MCH components. High Definition Multimedia Interface. HDMI supports standard, enhanced, or highdefinition video, plus multi-channel digital audio on a single cable. It transmits all ATSC HDTV standards and supports 8-channel digital audio, with bandwidth to spare for future requirements and enhancements (additional details are available through www.HDMI.org) This term is used synonymously with processor. An interrupt request signal where X stands for interrupts A,B,C, and D. Sixth generation I/O Controller Hub component that contains additional functionality ® compared to previous ICH6s. The Intel I/O Controller Hub component contains the primary PCI interface, LPC interface, USB2, ATA-100, and other I/O functions. It communicates with the GMCH over a proprietary interconnect called DMI. Internal Graphics Device. Liquid Crystal Display. Low Voltage Differential Signaling. A high speed, low power data transmission standard used for display connections to LCD panels. ® Core CRT DBI DDR DDR2 DMI DVI FSB Full Reset GMCH HDMI Host INTx Intel ICH6 ® IGD LCD LVDS 24 Datasheet Introduction R Term MCH Description The Memory Controller Hub (MCH) component contains the processor interface and DRAM controller; however, it does not contain an internal graphics device like the GMCH. It may also contain an x16 PCI Express port (typically the external graphics interface). It communicates with the I/O controller hub (ICH6*) and other I/O controller hubs over the DMI interconnect. Throughout this document the term MCH refers to the 82915P and 82915PL MCH. Note: (G)MCH is used when referring to both GMCH and MCH components. Message Signaled Interrupt. A transaction initiated outside the host, conveying interrupt information to the receiving agent through the same path that normally carries read and write commands. Third Generation Input Output (PCI Express) Graphics Attach called PCI Express Graphics. A high-speed serial interface whose configuration is software compatible with the existing PCI specifications. The specific PCI Express implementation intended for connecting the GMCH to an external graphics controller is a x16 link and replaces AGP. The physical PCI bus that is driven directly by the ICH6 component. Communication between Primary PCI and the GMCH occurs over DMI. Note that the Primary PCI bus is not PCI Bus 0 from a configuration standpoint. System Control Interrupt. SCI is used in ACPI protocol. Serial Digital Video Out (SDVO). Digital display channel that serially transmits digital display data to an external SDVO device. The SDVO device accepts this serialized format and then translates the data into the appropriate display format (i.e., TMDS, LVDS, TV-Out). This interface is not electrically compatible with the previous digital ® display channel - DVO. For the Intel 82915G GMCH, The SDVO interface is multiplexed on a portion of the x16 graphics PCI Express interface. Third party codec that uses SDVO as an input. An SDVO device may have a variety of output formats including: DVI, LVDS, HDMI, TV-Out, etc. An indication that an unrecoverable error has occurred on an I/O bus. System Management Interrupt. SMI is used to indicate any of several system conditions (such as thermal sensor events, throttling activated, access to System Management RAM, chassis open, or other system state related activity). A unit of DRAM corresponding to eight x8 SDRAM devices in parallel or four x16 SDRAM devices in parallel, ignoring ECC. These devices are usually, but not always, mounted on a single side of a DIMM. Transition Minimized Differential Signaling. Signaling interface from Silicon Image that is used in DVI and HDMI. Top Of Low Memory. The highest address below 4 GB for which a processor-initiated memory read or write transaction will create a corresponding cycle to DRAM on the memory interface. Voltage Controlled Oscillator. Unified Memory Architecture. UMA describes an IGD using system memory for its frame buffers. MSI PCI Express* Primary PCI SCI SDVO SDVO Device SERR SMI Rank TMDS TOLM VCO UMA Datasheet 25 Introduction R 1.2 Reference Documents Document Title ® Document Number/Location http://intel.com/design/chip sets/designex/301469.htm http://developer.intel.com/d esign/chipsets/datashts/30 1473.htm http://www.acpi.info/ http://www.acpi.info/ http://www.pcisig.com/spe cifications http://www.pcisig.com/spe cifications Intel 915G/915GV/910GL Express Chipset Thermal Design Guide Intel I/O Controller Hub 6 (ICH6) Family Datasheet ® Advanced Configuration and Power Interface Specification, Version 2.0 Advanced Configuration and Power Interface Specification, Version 1.0b The PCI Local Bus Specification, Version 2.3 PCI Express* Specification, Version 1.0a 1.3 GMCH (MCH) Overview The (G)MCH connects to the processor as shown in Figure 1-1, Figure 1-2, Figure 1-3, Figure 1-4, Figure 1-5, and Figure 1-6. A major role of the (G)MCH in a system is to manage the flow of information between its interfaces: the processor interface (FSB), the System Memory interface (DRAM controller), the Integrated Graphics interface (82915G/82915GV/82915GL/82910GL GMCH only), the External Graphics interface via PCI Express (82915G/82915P/82915PL MCH only), and the I/O Controller Hub through the DMI interface. This includes arbitrating between the interfaces when each initiates transactions. The (G)MCH supports one or two channels of DDR (82915G/82915GV/82915GL/82915P/82915PL/82910GL) or DDR2 (82915G/82915GV/82915P) SDRAM. The (G)MCH also supports the new PCI Express based external graphics attach. Thus, the 915G/915GV/915GL/910GL/915P and 915PL Express chipsets are NOT compatible with AGP (1X, 2X, 4X, or 8X). To increase system performance, the (G)MCH incorporates several queues and a write cache. The (G)MCH also contains advanced desktop power management logic. 1.3.1 Host Interface The (G)MCH is optimized for both the Pentium 4 processors in the LGA775 socket and the Celeron D processor in the FC-mPGA4 socket. The (G)MCH can use a single LGA 775 socket processor. The (G)MCH supports FSB frequency of 533/800 MT/s (133/200 MHz HCLK) using a scalable FSB Vcc_CPU (82910GL only supports 533 MT/s, 133 MHz HCLK). The (G)MCH supports the Pentium 4 processor subset of the Extended Mode Scaleable Bus Protocol. The primary enhancements over the Compatible Mode P6 bus protocol are: Source synchronous double-pumped (2) Address and Source synchronous quad-pumped (4x) Data. The (G)MCH supports 32-bit host addressing, decoding up to 4 GB of the processor’s memory address space. Host-initiated I/O cycles are decoded to PCI Express, DMI, or the (G)MCH 26 Datasheet Introduction R configuration space. Host-initiated memory cycles are decoded to PCI Express, DMI, or system memory. PCI Express device accesses to non-cacheable system memory are not snooped on the host bus. Memory accesses initiated from PCI Express using PCI semantics and from DMI to system memory will be snooped on the host bus. 1.3.2 System Memory Interface The (G)MCH integrates a system memory DDR/DDR2 controller with two, 64-bit wide interfaces (82910GL, 82915PL, and 82915GL supports DDR only). Only Double Data Rate (DDR/DDR2) memory is supported; consequently, the buffers support only SSTL_2/1.8 V signal interfaces. The memory controller interface is fully configurable through a set of control registers. Features of the (G)MCH memory controller include: • The (G)MCH System Memory Controller directly supports one or two channels of memory (each channel consisting of 64 data lines). • Supports two memory addressing organization options: ⎯ The memory channels are asymmetric: "Stacked" channels are assigned addresses serially. Channel B addresses are assigned after all Channel A addresses. ⎯ The memory channels are interleaved: Addresses are ping-ponged between the channels after each cache line (64-B boundary). • Available bandwidth up to: ⎯ 3.2 GB/s (DDR/DDR2 400) for single-channel mode ⎯ 6.4 GB/s in dual-channel interleaved mode assuming DDR or DDR2 400 MHz. ⎯ 8.5 GB/s in dual-channel interleaved mode assuming DDR2 533 MHz. • Supports DDR memory DIMM frequencies of 333 MHz and 400 MHz or DDR2 memory DIMM frequencies of 400 MHz and 533 MHz. All DIMMs in a system must be of the same type (e.g., all DDR or all DDR2, not mixed). The speed used in all channels is the speed of the slowest DIMM in the system. • 82910GL supports DDR memory only, DIMM frequencies of 333 MHz and 400 MHz, dual channel mode, 1-DIMM maximum per channel. • I/O Voltage of 2.6 V for DDR, and 1.8 V for DDR2. • Supports non-ECC memory only. • Supports 256-Mb, 512-Mb and 1-Gb DDR/DDR2 technologies • Supports only x8, x16, DDR/DDR2 devices with four banks and also supports eight bank, 1-Gbit DDR2 devices. • Supports opportunistic refresh • In dual channel mode the (G)MCH supports 64 simultaneously open pages (four ranks of eight bank devices* 2 channels) • Supports Partial Writes to memory using Data Mask (DM) signals. • Supports page sizes of 4 KB, 8 KB and 16 KB. • Supports a burst length of 8 for single-channel and dual-channel interleaved and asymmetric operating modes. • Supports unbuffered DIMMs. • SPD (Serial Presence Detect) scheme for DIMM detection support • Suspend-to-RAM support using CKE • Supports configurations defined in the JEDEC DDR/DDR2 DIMM specification only Datasheet 27 Introduction R By using 256-Mb technology, the smallest memory capacity possible is 128 MB, assuming singlechannel mode. (16M rows * 16b/(row*device) * 4 devices/DIMM-side * 1 DIMM-side/channel * 1 channel *1B/8b = 128 MB). By using 1-Gb technology in dual-channel interleaved mode, the largest memory capacity possible is 8 GB. (128M rows * 8b/(row*device) * 8 devices/DIMMside * 4 DIMM-sides/channel * 2 channels * 1B/8b * 1G/1024M = 8 GB). This exceeds a 32-bit address limit of 4 GB. In a 32-bit system, only the first 4 GB of memory will be accessible. The (G)MCH supports a memory thermal management scheme to selectively manage reads and/or writes. Memory thermal management can be triggered either by on-die thermal sensor, or by preset limits. Management limits are determined by weighted sum of various commands that are scheduled on the memory interface. 1.3.3 Direct Media Interface (DMI) Direct Media Interface (DMI) is the chip-to-chip connection between the (G)MCH and ICH6. This high-speed interface integrates advanced priority-based servicing allowing for concurrent traffic and true isochronous transfer capabilities. Base functionality is completely software transparent permitting current and legacy software to operate normally. To provide for true isochronous transfers and configurable Quality of Service (QoS) transactions, the ICH6 supports two virtual channels on DMI: VC0 and VC1. These two channels provide a fixed arbitration scheme where VC1 is always the highest priority. VC0 is the default conduit of traffic for DMI and is always enabled. VC1 must be specifically enabled and configured at both ends of the DMI link (i.e., the ICH6 and (G)MCH). Features of the DMI include: • A chip-to-chip connection interface to ICH6 • 2 GB/s point-to-point DMI to ICH6 (1 GB/s each direction) • 100 MHz reference clock (shared with PCI Express Graphics Attach). • 32-bit downstream addressing • APIC and MSI interrupt messaging support. Will send Intel-defined “End Of Interrupt” broadcast message when initiated by the processor. • Message Signaled Interrupt (MSI) messages • SMI, SCI and SERR error indication • Legacy support for ISA regime protocol (PHOLD/PHOLDA) required for parallel port DMA, floppy drive, and LPC bus masters 1.3.4 PCI Express* Graphics Interface (Intel® 82915G/82915P/ and 82915PL Only) The (G)MCH (82915G, 82915P, and 82915PL only) contains a 16-lane (x16) PCI Express port intended for an external PCI Express graphics card. The PCI Express port is compatible with the PCI Express Base Specification revision 1.0a. The x16 port operates at a frequency of 2.5 Gb/s on each lane while employing 8b/10b encoding, and supports a maximum theoretical bandwidth of 4 Gb/s each direction. The 82915G GMCH multiplexes the PCI Express interface with two Intel® SDVO ports. 28 Datasheet Introduction R Features of the PCI Express Interface include: • One x16 PCI Express port intended for graphics attach, compatible with the PCI Express Base Specification revision 1.0a. • Theoretical PCI Express transfer rate of 2.5 Gb/s. • Raw bit-rate on the data pins of 2.5 Gb/s, resulting in a theoretical bandwidth per pair of 250 MB/s given the 8b/10b encoding used to transmit data across this interface • Maximum theoretical realized bandwidth on the interface of 4 GB/s in each direction simultaneously, for an aggregate of 8 GB/s when (1)x16. • PCI Express Graphics Extended Configuration Space. The first 256 bytes of configuration space alias directly to the PCI Compatibility configuration space. The remaining portion of the fixed 4-KB block of memory-mapped space above that (starting at 100h) is known as extended configuration space. • PCI Express Enhanced Addressing Mechanism. Accessing the device configuration space in a flat memory mapped fashion. • Automatic discovery, negotiation, and training of link out of reset • Supports traditional PCI style traffic (asynchronous snooped, PCI ordering) • Supports traditional AGP style traffic (asynchronous non-snooped, PCI Express-relaxed ordering) • Hierarchical PCI-compliant configuration mechanism for downstream devices (i.e., normal PCI 2.3 Configuration space as a PCI-to-PCI bridge) • Supports “static” lane numbering reversal. This method of lane reversal is controlled by a Hardware Reset strap, and reverses both the receivers and transmitters for all lanes (e.g., TX15->TX0, RX15->RX0). This method is transparent to all external devices and is different than lane reversal as defined in the PCI Express Specification. In particular, link initialization is not affected by static lane reversal. 1.3.5 Integrated Graphics (Intel® 82915G/82915GV/82910GL/82915GL GMCH Only) The 82915G/82915GV/82910GL/915GL GMCH provides an integrated graphics device (IGD) delivering cost competitive 3D, 2D and video capabilities. The GMCH contains an extensive set of instructions for 3D operations, BLT and Stretch BLT operations, motion compensation, overlay, and display control. The GMCH’s video engines support video conferencing and other video applications. The GMCH does not support a dedicated local graphics memory interface, it may only be used in a UMA configuration. The GMCH also has the capability to support external graphics accelerators via the PCI Express Graphics port but cannot work concurrently with the integrated graphics devce. High bandwidth access to data is provided through the system memory port. The GMCH also provides 3D hardware acceleration for block level transfers of data (BLTs). 2D BLTs are considered a special case of 3D transfers and use the 3D acceleration. The BLT engine provides the ability to copy a source block of data to a destination and perform raster operations (e.g., ROP1, ROP2, and ROP3) on the data using a pattern, and/or another destination. Performing these common tasks in hardware reduces processor load, and thus improves performance. Datasheet 29 Introduction R GMCH graphics support includes: • Core Frequency of 333 MHz • High Quality 3D Setup and Render Engine ⎯ Setup matching processor geometry delivery rates ⎯ Triangle lists, strips and fans ⎯ Indexed vertex and flexible vertex formats ⎯ Vertex cache ⎯ Pixel accurate fast scissoring and clipping operation ⎯ Backface culling ⎯ Supports D3D and OpenGL pixelization rules ⎯ Anti-aliased lines ⎯ Sprite points ⎯ Zone Rendering Technology 3 ⎯ Shadow maps ⎯ Double-sided stencil • High-Quality Texture Engine ⎯ 533 MegaTexel/Sec Performance – 266 Mpixel/Sec fill rate up to 2 bilinear textures ⎯ Hardware Pixel Shader 2.0 ⎯ Per-pixel perspective corrected texture mapping ⎯ 2/10/10/10 texture format ⎯ Bi-cubic filtering ⎯ Single-pass quad texture compositing ⎯ Enhanced texture blending functions ⎯ 12 levels of detail mip map sizes from 1x1 to 2Kx2K ⎯ All texture formats including 32-bit RGBA and 8-bit palettes ⎯ Alpha and luminance maps ⎯ Texture color-keying/chromakeying ⎯ Bilinear, trilinear and anisotropic mip-mapped filtering ⎯ Cubic environment reflection mapping ⎯ Embossed and DOT3 bump-mapping ⎯ DXTn and FXT1 texture decompression ⎯ Non-power of 2 texture ⎯ Render to texture • Video DVD/PC-VCR ⎯ H/W Motion Compensation for MPEG2 ⎯ Dynamic Bob and Weave Support for Video Streams ⎯ Source Resolution up to 1920x1080 with 2 vertical taps ⎯ Software DVD At 30 fps, Full Screen ⎯ Supports 720x480 DVD Quality Encoding at low processor Utilization for PC-VCR or home ⎯ movie recording and editing • 3D Graphics Rendering Enhancements ⎯ 1.3 Dual Texture GigaPixel/Sec Fill Rate ⎯ Flat and Gouraud Shading ⎯ Color Alpha Blending for Transparency ⎯ Vertex and Programmable Pixel Fog and Atmospheric Effects ⎯ Color Specular Lighting ⎯ Z Bias Support ⎯ Dithering ⎯ Anti-Aliased Lines ⎯ 16- and 24-bit Z Buffering ⎯ 8-bit Stencil Buffering ⎯ Double and Triple Render Buffer Support ⎯ 16- and 32-bit Color ⎯ Destination Alpha ⎯ Maximum 3D Resolution Supported: 1600x1200x32@85Hz ⎯ Fast Clear Support • 2D Graphics ⎯ Optimized 256-bit BLT Engine ⎯ Alpha Stretch Blitter ⎯ Anti-aliased Lines ⎯ 32-bit Alpha Blended Cursor ⎯ Color Space Conversion ⎯ Programmable 3-Color Transparent Cursor ⎯ 8-, 16- and 32-bit Color ⎯ ROP Support • Video Overlay ⎯ Advanced Deinterlacing ⎯ Process Amplifier Color Control ⎯ Single High Quality Scalable Overlay • Multiple Overlay Functionality provided via Stretch Blitter (PIP, Video Conferencing, etc.) ⎯ 5-tap Horizontal, 2-tap Vertical Filtered Scaling ⎯ Independent Gamma Correction ⎯ Independent Brightness/Contrast/Saturation ⎯ Independent Tint/Hue Support ⎯ Destination Color-keying ⎯ Source Chroma-keying ⎯ Maximum Source Resolution: 720x480x32 ⎯ Maximum Overlay Display Resolution: 2048x1536x32 ⎯ Video Mixer Render (VMR) 30 Datasheet Introduction R 1.3.6 Analog and Intel® SDVO Displays (Intel® 82915G/82915GV/82910GL/82915GL GMCH Only) The GMCH provides interfaces to a progressive scan analog monitor and two SDVO ports (multiplexed with PCI Express x16 Graphics Port signals) capable of driving an ADD2 card. The digital display channels are capable of driving a variety of SDVO devices (e.g., TMDS, TV-Out). Note that SDVO only works with the Integrated Graphics Device (IGD). The GMCH provides two SDVO ports that are capable of driving up to a 200 MHz pixel clock each. The GMCH SDVO ports can each support a single-channel SDVO device. If both ports are active in single-channel mode, they can have different display timing and data. Alternatively, the SDVO ports can combine to support dual channel devices, supporting higher resolutions and refresh rates. The GMCH is compliant with DVI Specification 1.0. When combined with a DVI compliant external device and connector, the GMCH has a high-speed interface to a digital display (e.g., flat panel or digital CRT). The GMCH Supports Hot-Plug and Display for PCI Express* x16 Graphics. This is not supported for ADD2 cards. 1.3.7 System Interrupts The (G)MCH interrupt support includes: • Supports both 8259 and Pentium 4 processor FSB interrupt delivery mechanisms. • Supports interrupts signaled as upstream Memory Writes from PCI Express and DMI ⎯ MSIs routed directly to FSB ⎯ From I/OxAPICs 1.3.8 (G)MCH Clocking The differential FSB clock (HCLKP/HCLKN) can be set to either 133 MHz or 200 MHz (82915G/82915GV/82915GL/82915P/82915PL only). This supports FSB transfer rates of 533 MT/s and 800 MT/s (82915G/82915GV/82915GL/82915P/82915PL only). The Host PLL generates 2X, 4X, and 8X versions of the host clock for internal optimizations. The (G)MCH core clock is synchronized to the host clock. The internal and external memory clocks of 133 MHz and 200 MHz are generated from one of two (G)MCH PLLs that use the host clock as a reference. This includes 2X and 4X for internal optimizations. For the 82915G/82915P/82915PL (G)MCH, the PCI Express core clock of 250 MHz is generated from a separate PCI Express PLL. This clock uses the fixed 100 MHz Serial Reference Clock (GCLKP/GCLKN) for reference. For the 82915G/82915GV/82915GL/82910GL GMCH, display timings are generated from display PLLs that use a 96 MHz differential non-spread spectrum clock as a reference. Display PLLs can also use the SDVO_TVCLKIN[+/-] from an SDVO device as a reference. Datasheet 31 Introduction R All of the above mentioned clocks are capable of tolerating Spread Spectrum clocking as defined in the Clock Generator specification. Host, Memory, and PCI Express* x16 Graphics PLLs, and all associated internal clocks are disabled until PWROK is asserted. 1.3.9 Power Management (G)MCH Power Management support includes: • PC99 suspend to DRAM support (“STR”, mapped to ACPI state S3) • SMRAM space remapping to A0000h (128 KB) • Supports extended SMRAM space above 256 MB, additional 1-MB TSEG from the Base of graphics stolen memory (BSM) when enabled, and cacheable (cacheability controlled by processor) • ACPI Rev 1.0 compatible power management • Supports processor states: C0, C1, C2, C3, and C4 • Supports System states: S0, S1, S3, S4, and S5 • Supports processor Thermal Management 2 (TM2) • Microsoft Windows NT* Hardware Design Guide v1.0 compliant § 32 Datasheet Signal Description R 2 Signal Description This chapter provides a detailed description of (G)MCH 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 Section 2.11. The following notations are used to describe the signal type: GTL+ Open Drain GTL+ interface signal. Refer to the GTL+ I/O Specification for complete details. The (G)MCH integrates GTL+ termination resistors, and supports VTT of from 0.83 V to 1.65 V (including guardbanding). PCI-Express interface signals. These signals are compatible with PCI Express 1.0 Signaling Environment AC Specifications and are AC coupled. The buffers are not 3.3 V tolerant. Differential voltage specification = (|D+ - D-|) * 2 = 1.2 V maximum. Single-ended maximum = 1.5 V. Single-ended minimum = 0 V. Direct Media Interface signals. These signals are compatible with PCI Express 1.0 Signaling Environment AC Specifications, but are DC coupled. The buffers are not 3.3 V tolerant. Differential voltage specification = (|D+ - D-|) * 2 = 1.2 V maximum. Single-ended maximum = 1.5 V. Single-ended minimum = 0 V. CMOS buffers. 1.5 V tolerant. CMOS Open Drain buffers. 2.5 V tolerant. High Voltage CMOS buffers. 2.5 V tolerant. High Voltage CMOS input-only buffers. 3.3 V tolerant. Stub Series Termination Logic. These are 2.6 V output capable buffers. 2.6 V tolerant. Stub Series Termination Logic. These are 1.8 V output capable buffers. 1.8 V tolerant. Analog reference or output. May be used as a threshold voltage or for buffer compensation. PCIE DMI CMOS COD HVCMOS HVIN SSTL-2 SSTL-1.8 A Datasheet 33 Signal Description R Figure 2-1. Intel® (G)MCH Signal Interface Diagram HA[31:3]# HD[63:0] HADS# HBNR# HBPRI# HDBSY# HDEFER# HDRDY# HEDRDY# HHIT# HHITM# HLOCK# HREQ[4:0]# HPCREQ# HTRDY# HRS[2:0]# HCPURST# HBREQ0# HDINV[3:0]# HADSTB[1:0]# HDSTBP[3:0]#, HDSTBN[3:0]# BSEL[2:0] HRCOMP HSCOMP HSWING HVREF SCS_A[3:0]# SMA_A[13:0] SBS_A[2:0] SRAS_A# SCAS_A# SWE_A# SDQ_A[63:0] SDM_A[7:0] SDQS_A[7:0], SDQS_A[7:0]# SCKE_A[3:0] SCLK_A[5:0], SCLK_A[5:0]# SODT_A[3:0] SCS_B[3:0]# SMA_B[13:0] SBS_B[2:0] SRAS_B# SCAS_B# SWE_B# SDQ_B[63:0] SDM_B[7:0] SDQS_B[7:0], SDQS_B[7:0]# SCKE_B[3:0] SCLK_B[5:0], SCLK_B[5:0]# SODT_B[3:0] SRCOMP[1:0] SOCOMP[1:0] SM_SLEWIN[1:0] SM_SLEWOUT[1:0] SMVREF[1:0] HSYNC VSYNC RED, RED# GREEN, GREEN# BLUE, BLUE# REFSET DDC_CLK DDC_DATA Analog Display Intel® 82915G/ 82915GV/ 82910GL Only Processor System Bus Interface Intel® SDVO Device Interface1 SDVOB_GREEN-, SDVOB_GREEN+ SDVOB_BLUE-, SDVOB_BLUE+ SDVOC_RED- / SDVOB_ALPHA-, SDVOC_RED+ / SDVOB_ALPHA+ SDVOC_GREEN-, SDVOC_GREEN+ SDVOC_BLUE-, SDVOC_BLUE+ SDVOC_CLK-, SDVOC_CLK+ SDVO_TVCLKIN-, SDVO_TVCLKIN, SDVOB_INT-, SDVOB_INT+ SDVOC_INT-, SDVOC_INT+ SDVO_STALL-, SDVO_STALL+ SDVO_CTRLCLK SDVO_CTRLDATA Intel® 82915G/ 82915GV/ 82910GL Only PCI Express x16 Graphics Port System Memory2 DDR/ DDR2 Channel A EXP_RXN[15:0], EXP_RXP[15:0] EXP_TXN[15:0], EXP_TXP[15:0] EXP_COMPO EXP_COMPI EXP_SLR HCLKP, HCLKN GCLKP, GCLKN DREFCLKN, DREFCLKP RSTIN# PWROK EXTTS# BSEL[2:0] MTYPE ICH_SYNC# Intel® 82915G/ 82915P Only Clocks, Reset, and Misc. System Memory2 DDR/ DDR2 Channel B Direct Media Interface DMI_RXP[3:0], DMI_RXN[3:0] DMI_TXP[3:0], DMI_TXN[3:0] Voltage Reference, and Power System Memory2 DDR/DDR2 Ref./ Comp. VCC VTT VCC_EXP VCCSM VCC2 VCCA_EXPPLL VCCA_DPLLA VCCA_DPLLB VCCA_HPLL VCCA_SMPLL Intel® VSS 82915G/ VCCA_DAC 82915GV/ VSSA_DAC 82910GL Only Note: 1. SDVO signals on the 82915G GMCH are multiplexed with the PCI Express x16 Graphics Port signals. 2. The 82910GL GMCH only supports DDR (not DDR2). Signal_Info 34 Datasheet Signal Description R 2.1 Host Interface Signals Note: Unless otherwise noted, the voltage level for all signals in this interface is tied to the termination voltage of the Host Bus (VTT). Signal Name HADS# Type I/O GTL+ HBNR# I/O GTL+ HBPRI# O GTL+ Description Address Strobe: The processor bus owner asserts HADS# to indicate the first of two cycles of a request phase. The (G)MCH can assert this signal for snoop cycles and interrupt messages. Block Next Request: This signal is used to block the current request bus owner from issuing new requests. This signal is used to dynamically control the processor bus pipeline depth. Priority Agent Bus Request: The (G)MCH 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 will cause the current symmetric owner to stop issuing new transactions unless the HLOCK# signal was asserted. Bus Request 0: The (G)MCH pulls the processor’s bus HBREQ0# signal low during HCPURST#. The processor samples this signal on the active-toinactive transition of HCPURST#. The minimum setup time for this signal is 4 HCLKs. The minimum hold time is 2 clocks and the maximum hold time is 20 HCLKs. HBREQ0# should be tristated after the hold time requirement has been satisfied. CPU Reset: The HCPURST# pin is an output from the (G)MCH. The (G)MCH asserts HCPURST# while RSTIN# is asserted and for approximately 1 ms after RSTIN# is de-asserted. The HCPURST# allows the processors to begin execution in a known state. Note that the Intel ICH6 must provide processor frequency select strap setup and hold times around HCPURST#. This requires strict synchronization between (G)MCH HCPURST# de-assertion and the Intel® ICH6 driving the straps. HDBSY# I/O GTL+ HDEFER# O GTL+ HDINV[3:0]# I/O GTL+ Data Bus Busy: This signal is used by the data bus owner to hold the data bus for transfers requiring more than one cycle. Defer: Signals that the (G)MCH will terminate the transaction currently being snooped with either a deferred response or with a retry response. ® HBREQ0# I/O GTL+ HCPURST# O GTL+ Dynamic Bus Inversion: Driven along with the HD[63:0] signals. Indicates if the associated signals are inverted or not. HDINV[3:0]# are asserted such that the number of data bits driven electrically low (low voltage) within the corresponding 16 bit group never exceeds 8. HDINVx# HDINV3# HDINV2# HDINV1# HDINV0# Data Bits HD[63:48] HD[47:32] HD[31:16] HD[15:0] Datasheet 35 Signal Description R Signal Name HDRDY# Type I/O GTL+ Description Data Ready: This signal is asserted for each cycle that data is transferred. HEDRDY# O GTL+ Early Data Ready: This signal indicates that the data phase of a read transaction will start on the bus exactly one common clock after assertion. Host Address Bus: HA[31:3]# connect to the processor address bus. During processor cycles, the HA[31:3]# are inputs. The (G)MCH drives HA[31:3]# during snoop cycles on behalf of DMI and PCI Express Graphics initiators. HA[31:3]# are transferred at 2x rate. Host Address Strobe: The source synchronous strobes used to transfer HA[31:3]# and HREQ[4:0] at the 2x transfer rate. Host Data: These signals are connected to the processor data bus. Data on HD[63:0] is transferred at 4x rate. Note that the data signals may be inverted on the processor bus, depending on the HDINV[3:0]# signals. Differential Host Data Strobes: The differential source synchronous strobes are used to transfer HD[63:0] and HDINV[3:0]# at 4x transfer rate. These signals are named this way because they are not level sensitive. Data is captured on the falling edge of both strobes. Hence, they are pseudo-differential, and not true differential. Strobes HDSTBP3#, HDSTBN3# HDSTBP2#, HDSTBN2# HDSTBP1#, HDSTBN1# HDSTBP0#, HDSTBN0# Data HD[63:48] HD[47:32] HD[31:16] HD[15:0] Bits HDINV3# HDINV2# HDINV1# HDINV0# HA[31:3]# I/O GTL+ HADSTB[1:0]# I/O GTL+ HD[63:0] I/O GTL+ HDSTBP[3:0]# HDSTBN[3:0]# I/O GTL+ HHIT# I/O GTL+ Hit: This signal indicates that a caching agent holds an unmodified version of the requested line. Also, driven in conjunction with HHITM# by the target to extend the snoop window. Hit Modified: This signal indicates that a caching agent holds a modified version of the requested line and that this agent assumes responsibility for providing the line. This signal is also driven in conjunction with HHIT# to extend the snoop window. Host Lock: All processor bus cycles sampled with the assertion of HLOCK# and HADS#, until the negation of HLOCK# must be atomic (i.e., no DMI or PCI Express Graphics accesses to DRAM are allowed when HLOCK# is asserted by the processor). Precharge Request: The processor provides a “hint” to the (G)MCH that it is OK to close the DRAM page of the memory read request with which the hint is associated. The (G)MCH uses this information to schedule the read request to memory using the special “AutoPrecharge” attribute. This causes the DRAM to immediately close (Precharge) the page after the read data has been returned. This allows subsequent processor requests to more quickly access information on other DRAM pages, since it will no longer be necessary to close an open page prior to opening the proper page. Asserted by the requesting agent during both halves of Request Phase. The same information is provided in both halves of the request phase. HHITM# I/O GTL+ HLOCK# I/O GTL+ HPCREQ# I GTL+ 2x 36 Datasheet Signal Description R Signal Name HREQ[4:0]# Type I/O GTL+ 2x Description Host Request Command: These signals define the attributes of the request. HREQ[4:0]# are transferred at 2x rate. They are asserted by the requesting agent during both halves of Request Phase. In the first half the signals define the transaction type to a level of detail that is sufficient to begin a snoop request. In the second half the signals carry additional information to define the complete transaction type. The transactions supported by the (G)MCH Host Bridge are defined in the Host Interface section of this document. HTRDY# O GTL+ Host Target Ready: This signal indicates that the target of the processor transaction is able to enter the data transfer phase. Response Signals: These signals indicate the type of response as shown below: 000 = Response type 001 = Idle state 010 = Retry response 011 = Deferred response 100 = Reserved (not driven by (G)MCH) 101 = Hard Failure (not driven by (G)MCH) 110 = No data response 111 = Implicit Writeback 111 = Normal data response HRS[2:0]# O GTL+ BSEL[2:0] I CMOS Bus Speed Select: At the de-assertion of RSTIN#, the value sampled on these pins determines the expected frequency of the bus. Host RCOMP: Used to calibrate the Host GTL+ I/O buffers. This signal is powered by the Host Interface termination rail (VTT). Slew Rate Compensation: Compensation for the Host Interface. HRCOMP I/O CMOS HSCOMP I/O CMOS HSWING I A Host Voltage Swing: This signal provides the reference voltage used by FSB RCOMP circuits. HSWING is used for the signals handled by HRCOMP. Host Reference Voltage Reference: Voltage input for the data, address, and common clock signals of the Host GTL interface. HVREF I A Datasheet 37 Signal Description R 2.2 DDR/DDR2 DRAM Channel A Interface Note that the 82910GL, 82915GL, and 82915PL (G)MCH only supports DDR DRAM. Signal Name SCLK_A[5:0] Type O SSTL2/1.8 Description SDRAM Differential Clock: (3 per DIMM). SCLK_Ax and its complement SCLK_Ax# signal make a differential clock pair output. The crossing of the positive edge of SCLK_Ax and the negative edge of its complement SCLK_Ax# are used to sample the command and control signals on the SDRAM. SDRAM Complementary Differential Clock: (3 per DIMM) These are the complementary differential DDR/DDR2 clock signals. Chip Select: (1 per Rank) These signals select particular SDRAM components during the active state. There is one chip select for each SDRAM rank. Memory Address: These signals are used to provide the multiplexed row and column address to the SDRAM Bank Select: These signals define which banks are selected within each SDRAM rank DDR2: 1-Gb technology is 8 banks. DDR: 1-Gb technology is 4 banks. SBS_A[2] is not used. Row Address Strobe: This signal is used with SCAS_A# and SWE_A# (along with SCS_A#) to define the SDRAM commands. Column Address Strobe: This signal is used with SRAS_A# and SWE_A# (along with SCS_A#) to define the SDRAM commands. Write Enable: This signal is used with SCAS_A# and SRAS_A# (along with SCS_A#) to define the SDRAM commands. Data Lines: SDQ_A signals interface to the SDRAM data bus. SCLK_A[5:0]# O SSTL2/1.8 O SSTL2/1.8 O SSTL2/1.8 O SSTL2/1.8 SCS_A[3:0]# SMA_A[13:0] SBS_A[2:0] SRAS_A# O SSTL2/1.8 O SSTL2/1.8 O SSTL2/1.8 I/O SSTL2/1.8 2x O SSTL2/1.8 2X I/O SSTL2/1.8 2x I/O SSTL-1.8 2x SCAS_A# SWE_A# SDQ_A[63:0] SDM_A[7:0] Data Mask: When activated during writes, the corresponding data groups in the SDRAM are masked. There is one SDM_Ax signal for every data byte lane. Data Strobes: For DDR, the rising and falling edges of SDQS_Ax are used for capturing data during read and write transactions. For DDR2, SDQS_Ax and its complement SDQS_Ax# signal make up a differential strobe pair. The data is captured at the crossing point of SDQS_Ax and its complement SDQS_Ax# during read and write transactions. Data Strobe Complements (DDR2 only): These signals are the complementary DDR2 strobe signals. SDQS_A[7:0] SDQS_A[7:0]# 38 Datasheet Signal Description R Signal Name SCKE_A[3:0] Type O SSTL2/1.8 O SSTL-1.8 Description Clock Enable: (1 per Rank) SACKE is used to initialize the SDRAMs during power-up, to power-down SDRAM ranks, and to place all SDRAM ranks into and out of self-refresh during Suspend-to-RAM. On Die Termination (DDR2 only): Active On-die Termination Control signals for DDR2 devices. SODT_A[3:0] 2.3 DDR/DDR2 DRAM Channel B Interface Note that the 82910GL, 82915GL, and 82915PL (G)MCH only supports DDR DRAM. Signal Name SCLK_B[5:0] Type O SSTL2/1.8 Description SDRAM Differential Clock: (3 per DIMM) SCLK_Bx and its complement SCLK_Bx# signal make a differential clock pair output. The crossing of the positive edge of SCLK_Bx and the negative edge of its complement SCLK_Bx# are used to sample the command and control signals on the SDRAM. SDRAM Complementary Differential Clock: (3 per DIMM) These are the complementary differential DDR/DDR2 clock signals. Chip Select: (1 per Rank) These signals select particular SDRAM components during the active state. There is one chip select for each SDRAM rank Memory Address: These signals are used to provide the multiplexed row and column address to the SDRAM Bank Select: These signals define which banks are selected within each SDRAM rank DDR2: 1-Gb technology is 8 banks. DDR: 1-Gb technology is 4 banks. SBS_B[2] is not used Row Address Strobe: This signal is used with SCAS_B# and SWE_B# (along with SCS_B#) to define the SDRAM commands Column Address Strobe: This signal is used with SRAS_B# and SWE_B# (along with SCS_B#) to define the SDRAM commands. Write Enable: This signal is used with SCAS_B# and SRAS_B# (along with SCS_B#) to define the SDRAM commands. Data Lines: SDQ_Bx signals interface to the SDRAM data bus SCLK_B[5:0]# O SSTL2/1.8 O SSTL2/1.8 O SSTL2/1.8 O SSTL2/1.8 SCS_B[3:0]# SMA_B[13:0] SBS_B[2:0] SRAS_B# O SSTL2/1.8 O SSTL2/1.8 O SSTL2/1.8 I/O SSTL2/1.8 2x O SSTL2/1.8 2x SCAS_B# SWE_B# SDQ_B[63:0] SDM_B[7:0] Data Mask: When activated during writes, the corresponding data groups in the SDRAM are masked. There is one SDM_Bx signal for every data byte lane. Datasheet 39 Signal Description R Signal Name SDQS_B[7:0] Type I/O SSTL2/1.8 2x I/O SSTL-1.8 2x O SSTL2/1.8 O SSTL-1.8 Description Data Strobes: For DDR the rising and falling edges of SDQS_Bx are used for capturing data during read and write transactions. For DDR2, SDQS_Bx and its complement SDQS_Bx# make up a differential strobe pair. The data is captured at the crossing point of SDQS_Bx and its complement SDQS_Bx# during read and write transactions. Data Strobe Complements (DDR2 only): These signals are the complementary DDR2 Strobe signals. Clock Enable: (1 per Rank) SCKE_B is used to initialize the SDRAMs during power-up, to power-down SDRAM ranks, and to place all SDRAM ranks into and out of self-refresh during Suspend-to-RAM. On Die Termination (DDR2 only): Active On-die Termination Control signals for DDR2 devices. SDQS_B[7:0]# SCKE_B[3:0] SODT_B[3:0] 2.4 DDR/DDR2 DRAM Reference and Compensation Note that the 82910GL, 82915GL, and 82915PL (G)MCH only supports DDR DRAM. Signal Name SRCOMP[1:0] SOCOMP[1:0] SM_SLEWIN[1:0] Type I/O I/O A I A SM_SLEWOUT[1:0] SMVREF[1:0] O A I A System Memory RCOMP DDR2 On-Die DRAM Over Current Detection (OCD) driver compensation (DDR2 only) Buffer Slew Rate Input: Slew Rate characterization buffer input for X and Y orientation. Buffer Slew Rate Output: Slew Rate characterization buffer output for X and Y orientation SDRAM Reference Voltage: Reference voltage inputs for each DQ, DM, DQS, and DQS# input signals. Description 40 Datasheet Signal Description R 2.5 PCI Express* x16 Graphics Port Signals (Intel® 82915G, 82915P, 82915PL Only) Unless otherwise specified, PCI Express Graphics signals are AC coupled, so the only voltage specified is a maximum 1.2 V differential swing. Signal Name EXP_RXN[15:0] EXP_RXP[15:0] EXP_TXN[15:0] EXP_TXP[15:0] EXP_COMPO Type I/O PCIE O PCIE I A I A I CMOS Description PCI Express Graphics Receive Differential Pair PCI Express Graphics Transmit Differential Pair PCI Express Graphics Output Current Compensation Note: EXP_COMP0 is used for DMI current compensation. PCI Express Graphics Input Current Compensation Note: EXP_COMPI is used for DMI current compensation. PCI Express* Static Lane Reversal: The (G)MCH’s PCI Express lane numbers are reversed. For example, the (G)MCH PCI Express interface signals can be configured as follows: Ball C10 A9 … N3 P1 Normal Operation EXP_TXP0 EXP_TXP1 … EXP_TXP14… EXP_TXP15 Lane Reversed EXP_TXP15 EXP_TXP14 … EXP_TXP1… EXP_TXP0 EXP_COMPI EXP_SLR 0 = (G)MCH’s PCI Express lane numbers are reversed 1 = Normal operation Datasheet 41 Signal Description R 2.6 Analog Display Signals (Intel® 82915G/82915GV/82915GL/82910GL GMCH Only) Signal Name RED Type O A Description RED Analog Video Output: This signal is a CRT Analog video output from the internal color palette DAC. The DAC is designed for a 37.5 Ω routing impedance; however, the terminating resistor to ground will be 75 Ω (e.g., 75 Ω resistor on the board, in parallel with a 75 Ω CRT load). REDB Analog Output: This signal is an analog video output from the internal color palette DAC. It should be shorted to the ground plane. GREEN Analog Video Output: This signal is a CRT Analog video output from the internal color palette DAC. The DAC is designed for a 37.5 Ω routing impedance; however, the terminating resistor to ground will be 75 Ω (e.g., 75 Ω resistor on the board, in parallel with a 75 Ω CRT load). GREENB Analog Output: This signal is an analog video output from the internal color palette DAC. It should be shorted to the ground plane. BLUE Analog Video Output: This signal is a CRT Analog video output from the internal color palette DAC. The DAC is designed for a 37.5 Ω routing impedance; however, the terminating resistor to ground will be 75 Ω (e.g., 75 Ω resistor on the board, in parallel with a 75 Ω CRT load). BLUEB Analog Output: This signal is an analog video output from the internal color palette DAC. It should be shorted to the ground plane. Resistor Set: Set point resistor for the internal color palette DAC. A 255 Ω 1% resistor is required between REFSET and motherboard ground. CRT Horizontal Synchronization: This signal is used as the horizontal sync (polarity is programmable) or “sync interval”. 2.5 V output CRT Vertical Synchronization: This signal is used as the vertical sync (polarity is programmable). 2.5 V output. Monitor Control Clock. This signal may be used as the DDC_CLK for a secondary multiplexed digital display connector. Monitor Control Data. This signal may be used as the DDC_Data for a secondary multiplexed digital display connector. RED# O A GREEN O A GREEN# O A BLUE O A BLUE# O A REFSET O A HSYNC O 2.5 V CMOS O 2.5 V CMOS I/O 2.5 V CMOS I/O 2.5 V CMOS VSYNC DDC_CLK DDC_DATA 42 Datasheet Signal Description R 2.7 Clocks, Reset, and Miscellaneous Signal Name HCLKP HCLKN GCLKP GCLKN Type I CMOS I CMOS Description Differential Host Clock In: These pins receive a differential host clock from the external clock synthesizer. This clock is used by all of the (G)MCH logic that is in the Host clock domain. Differential PCI Express Graphics Clock In: These pins receive a differential 100 MHz serial reference clock from the external clock synthesizer. This clock is used to generate the clocks necessary for the support of PCI Express. Display PLL Differential Clock In DREFCLKN DREFCLKP RSTIN# I CMOS I HVIN Reset In: When asserted, this signal will asynchronously reset the (G)MCH logic. This signal is connected to the PLTRST# output of the ® Intel ICH6. All PCI Express Graphics Attach output signals will also tristate compatible with PCI Express* Specification Rev 1.0a. This input should have a Schmitt trigger to avoid spurious resets. This signal is required to be 3.3 V tolerant. PWROK I HVIN Power OK: When asserted, PWROK is an indication to the (G)MCH that core power has been stable for at least 10 us. External Thermal Sensor Input: This signal may connect to a precision thermal sensor located on or near the DIMMs. If the system temperature reaches a dangerously high value, then this signal can be used to trigger the start of system thermal management. This signal is activated when an increase in temperature causes a voltage to cross some threshold in the sensor. Memory Type Select Strap. This signal is a strapping option that indicates the type of system memory. For the 82910GL GMCH, this signal must be tied to ground. 0 = DDR2 1 = DDR EXTTS# I HVCMOS MTYPE I CMOS ICH_SYNC# O HVCMOS ICH Sync: This signal is connected to the MCH_SYNCH# signal on the ICH6. 2.8 Direct Media Interface (DMI) Signal Name DMI_RXP[3:0] DMI_RXN[3:0] DMI_TXP[3:0] DMI_TXN[3:0] Type I/O DMI O DMI Description Direct Media Interface: These signals are the receive differential pair (Rx). Direct Media Interface: These signals are the transmit differential pair (Tx). Datasheet 43 Signal Description R 2.9 Intel® Serial DVO (SDVO) Interface (82915G/82915GV/82915GL/82910GL GMCH Only) For the 82915G/82915GV/82915GL/82910GL GMCH, all but two of the pins in this section are multiplexed with the lower 8 lanes of the PCI Express interface. Note: The SDVO interface does not support static lane reversal (e.g., SDVOB_CLK# will originate from the same ball whether the PCI Express interface is lane-reversed mode or not. Signal Name SDVOB_GREENSDVOB_GREEN+ SDVOB_BLUESDVOB_BLUE+ SDVOC_RED- / SDVOB_ALPHASDVOC_RED+ / SDVOB_ALPHA+ SDVOC_GREENSDVOC_GREEN+ SDVOC_BLUESDVOC_BLUE+ SDVOC_CLKSDVOC_CLK+ SDVO_TVCLKINSDVO_TVCLKIN+ SDVOB_INTSDVOB_INT+ SDVOC_INT+ SDVOC_INTType O PCIE O PCIE O PCIE O PCIE O PCIE O PCIE O PCIE O PCIE O PCIE O PCIE O PCIE O PCIE I PCIE I PCIE I PCIE I PCIE I PCIE I PCIE Description Serial Digital Video Channel B Green Complement. This signal is multiplexed with EXP_TXN1. Serial Digital Video Channel B Green. This signal is multiplexed with EXP_TXP1. Serial Digital Video Channel B Blue Complement. This signal is multiplexed with EXP_TXN2. Serial Digital Video Channel B Blue. This signal is multiplexed with EXP_TXP2. Serial Digital Video Channel C Red Complement Channel B Alpha Complement. This signal is multiplexed with EXP_TXN4. Serial Digital Video Channel C Red Channel B Alpha. This signal is multiplexed with EXP_TXP4. Serial Digital Video Channel C Green Complement. This signal is multiplexed with EXP_TXN5. Serial Digital Video Channel C Green. This signal is multiplexed with EXP_TXP5. Serial Digital Video Channel C Blue Complement. This signal is multiplexed with EXP_TXN6. Serial Digital Video Channel C Blue. This signal is multiplexed with EXP_TXP6. Serial Digital Video Channel C Clock Complement. This signal is multiplexed with EXP_TXN7. Serial Digital Video Channel C Clock. This signal is multiplexed with EXP_TXP7. Serial Digital Video TVOUT Synchronization Clock Complement. This signal is multiplexed with EXP_RXN0. Serial Digital Video TVOUT Synchronization Clock. This signal is multiplexed with EXP_RXP0. Serial Digital Video Input Interrupt Complement. This signal is multiplexed with EXP_RXN1. Serial Digital Video Input Interrupt. This signal is multiplexed with EXP_RXP1. Serial Digital Video Input Interrupt. This signal is multiplexed with EXP_RXP5. Serial Digital Video Input Interrupt Complement. This signal is multiplexed with EXP_RXN5. 44 Datasheet Signal Description R Signal Name SDVO_STALLSDVO_STALL+ SDVO_CTRLCLK SDVO_CTRLDATA Type I PCIE I PCIE I/O COD I/O COD Description Serial Digital Video Field Stall Complement. This signal is multiplexed with EXP_RXN2. Serial Digital Video Field Stall.. This signal is multiplexed with EXP_RXP2. Serial Digital Video Device Control Clock. Serial Digital Video Device Control Data. This signal also provides a strapping option. Device 1 (Host-PCI Express Bridge) is disabled on Reset when the SDVO Presence strap (SDVO_CTLRDATA) is sampled high, and is enabled when this signal is sampled low. 2.10 Power and Ground Name VCC VTT VCC_EXP VCCSM Voltage 1.5 V 1.2 V 1.5 V 1.8 V / 2.6 V Core Power. Processor System Bus Power. PCI Express* and DMI Power. System Memory Power. DDR2: VCCSM = 1.8 V DDR: VCCSM = 2.6 V VCC2 VCCA_EXPPLL VCCA_DPLLA VCCA_DPLLB VCCA_HPLL VCCA_SMPLL VCCA_DAC VSS VSSA_DAC 2.5 V 1.5 V 1.5 V 1.5 V 1.5 V 1.5 V 2.5 V 0V 0V 2.5 V CMOS Power. PCI Express PLL Analog Power. Display PLL A Analog Power. Display PLL B Analog Power. Host PLL Analog Power. System Memory PLL Analog Power. Display DAC Analog Power. This signal is on the 82915G/82915GV/82915GL/82910GL GMCH only. Ground. Ground. This signal is on the 82915G/82915GV/82915GL/82910GL GMCH only. Description Datasheet 45 Signal Description R 2.11 Reset States and Pull-up/Pull-downs This section describes the expected states of the (G)MCH I/O buffers during and immediately after the assertion of RSTIN#. This table only refers to the contributions on the interface from the (G)MCH and does not reflect any external influence (such as external pull-up/pull-down resistors or external drivers). Legend: CMCT: DRIVE: TERM: LV: HV: IN: ISO: TRI: PU: PD: STRAP: Common Mode Center Tapped. Differential signals are weakly driven to the common mode central voltage. Strong drive (to normal value supplied by core logic if not otherwise stated) Normal termination devices are turned on Low voltage High voltage Input buffer enabled Isolate input buffer so that it doesn’t oscillate if input left floating Tri-state Weak internal pull-up Weak internal pull-down Strap input sampled during assertion or on the de-asserting edge of RSTIN# Table 2-1. Host Interface Reset and S3 States Interface Signal Name I/O State During RSTIN# Assertion DRIVE LV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV State After RSTIN# Deassertion TERM HV after approximately 1ms TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV S3 Pull-up/ Pull-down Host I/F HCPURST# HADSTB[1:0]# HA[31:3]# HD[63:0] HDSTBP[3:0]# HDSTBN[3:0]# HDINV[3:0]# HADS# HBNR# HBPRI# HDBSY# HDEFER# HDRDY# HEDRDY# O I/O I/O I/O I/O I/O I/O I/O I/O O I/O O I/O O TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) 46 Datasheet Signal Description R Interface Signal Name I/O State During RSTIN# Assertion TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV IN TRI State After RSTIN# Deassertion TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV TERM HV IN TRI after RCOMP S3 Pull-up/ Pull-down Host I/F HHIT# HHITM# HLOCK# HREQ[4:0]# HTRDY# HRS[2:0]# HBREQ0# HPCREQ# HVREF HRCOMP I/O I/O I/O I/O O O I/O I I I/O TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI (No VTT) TRI TRI 20 Ω resistor for board with target impedance of 60 Ω HSWING HSCOMP I I/O IN TRI IN TRI TRI Table 2-2. System Memory (DDR2) Reset and S3 States Interface Signal Name I/O State During RSTIN# Assertion State After RSTIN# Deassertion S3 Pull-up/ Pull-down System Memory (DDR2) Channel A SCLK_A[5:0] SCLK_A[5:0]# SCS_A[3:0]# SMA_A[13:0] SBS_A[2:0] SRAS_A# SCAS_A# SWE_A# SDQ_A[63:0] SDM_A[7:0] SDQS_A[7:0] SDQS_A[7:0]# SCKE_A[3:0] SODT_A[3:0] O O O O O O O O I/O O I/O I/O O O TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI LV LV TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI LV LV TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI LV LV Datasheet 47 Signal Description R Interface System Memory (DDR2) Signal Name I/O State During RSTIN# Assertion State After RSTIN# Deassertion S3 Pull-up/ Pull-down Channel B SCLK_B[5:0] SCLK_B[5:0]# SCS_B[3:0]# SMA_B[13] SMA_B[12:11] SMA_B[10:8] SMA_B[7] SMA_B[6:0] SBS_B[2] SBS_B[1:0] SRAS_B# SCAS_B# SWE_B# SDQ_B[63:0] SDM_B[7:0] SDQS_B[7:0] SDQS_B[7:0]# SCKE_B[3:0] SODT_B[3:0] SRCOMP0 SRCOMP1 SM_SLEWIN[1:0] SM_SLEWOU{1:0] SMVREF[1:0] SOCOMP[1:0] O O O O O O O O O O O O O I/O O I/O I/O O O I/O I/O I O I I/O TRI TRI TRI TRI LV TRI LV TRI LV TRI TRI TRI TRI TRI TRI TRI TRI LV LV TRI TRI IN TRI IN TRI TRI TRI TRI TRI LV TRI LV TRI LV TRI TRI TRI TRI TRI TRI TRI TRI LV LV TRI (after RCOMP) TRI (after RCOMP) IN TRI (after RCOMP) IN TRI TRI TRI TRI TRI LV TRI LV TRI LV TRI TRI TRI TRI TRI TRI TRI TRI LV LV TRI TRI IN TRI IN TRI DDR2: 40 Ω resistor to ground 48 Datasheet Signal Description R Table 2-3. System Memory (DDR) Reset and S3 States Interface Signal Name I/O State During RSTIN# Assertion State After RSTIN# De-assertion S3 Pull-up/ Pull-down System Memory (DDR) Channel A SCLK_A[5:0] SCLK_A[5:0]# SMA_A[13:9] SMA_A[8] SMA_A[7:6] SMA_A[5] SMA_A[4:0] SBS_A[2:0] SCS_A[3]# SCS_A[2:1]# SCS_A[0]# SRAS_A# SCAS_A# SWE_A# SDQ_A[63:0] SDM_A[7:0] SDQS_A[7:0] SDQS_A[7:0]# SCKE_A[3:0] O O O O O O O O O O O O O O I/O O I/O I/O O TRI TRI TRI LV TRI LV TRI TRI TRI LV TRI TRI LV TRI TRI TRI TRI TRI LV TRI TRI TRI LV TRI LV TRI TRI TRI LV TRI TRI LV TRI TRI TRI TRI TRI LV TRI TRI TRI LV TRI LV TRI TRI TRI LV TRI TRI LV TRI TRI TRI TRI TRI LV System Memory (DDR) Channel B SCLK_B[5:0] SCLK_B[5:0]# SMA_B[13:0] SMA_B[0] SBS_B[2] SBS_B[1] SBS_B[0] SCS_B[3]# SCS_B[2:0]# SRAS_B# SCAS_B# O O O O O O O O O O O TRI TRI TRI LV TRI LV TRI LV TRI TRI TRI TRI TRI TRI LV TRI LV TRI LV TRI TRI TRI TRI TRI TRI LV TRI LV TRI LV TRI TRI TRI Datasheet 49 Signal Description R Interface Signal Name I/O State During RSTIN# Assertion TRI TRI TRI TRI TRI LV TRI TRI IN TRI IN TRI State After RSTIN# De-assertion TRI TRI TRI TRI TRI LV TRI (after RCOMP) TRI (after RCOMP) IN TRI (after RCOMP) IN TRI S3 Pull-up/ Pull-down System Memory (DDR) SWE_B# SDQ_B[63:0] SDM_B[7:0] SDQS_B[7:0] SDQS_B[7:0]# SCKE_B[3:0] SRCOMP0 SRCOMP1 SM_SLEWIN[1:0] SM_SLEWOU[1:0] SMVREF[1:0] SOCOMP[1:0] O I/O O I/O I/O O I/O I/O I O I I/O TRI TRI TRI TRI TRI LV TRI TRI IN TRI IN TRI DDR2: 40 Ω resistor to ground Table 2-4. PCI Express* Graphics x16 Port Reset and S3 States Interface Signal Name I/O State During RSTIN# Assertion CMCT CMCT CMCT 1.0 V CMCT 1.0 V TRI TRI State After RSTIN# De-assertion CMCT CMCT CMCT 1.0 V CMCT 1.0 V TRI (after RCOMP) TRI (after RCOMP) S3 Pull-up/ Pull-down PCI Express*Graphics EXP_RXN[15:0] EXP_RXP[15:0] EXP_TXN[15:0] EXP_TXP[15:0] EXP_COMPO EXP_COMPI I/O I/O O O I I CMCT CMCT CMCT 1.0 V CMCT 1.0 V TRI TRI Table 2-5. DMI Reset and S3 States Interface Signal Name I/O State During RSTIN# Assertion CMCT CMCT CMCT 1.0 V CMCT 1.0 V State After RSTIN# De-assertion CMCT CMCT CMCT 1.0 V CMCT 1.0 V S3 Pull-up/ Pulldown DMI DMI_RXN[3:0] DMI_RXP[3:0] DMI_TXN[3:0] DMI_TXP[3:0] I/O I/O O O CMCT CMCT CMCT 1.0 V CMCT 1.0 V 50 Datasheet Signal Description R Table 2-6. Clocking Reset and S3 States Interface Signal Name HCLKN HCLKP GCLKN GCLKP DREFCLKN DREFCLKP I/O I I I I I I State During RSTIN# Assertion IN IN IN IN IN IN State After RSTIN# Deassertion IN IN IN IN IN IN S3 Pull-up/ Pull-down Clocks IN IN IN IN IN IN Table 2-7. MISC Reset and S3 States Interface Signal Name RSTIN# PWROK EXTTS# BSEL[2:0] MTYPE EXP_SLR ICH_SYNC# SDVO_CTRLCLK SDVO_CTRLDATA I/O I I I I I I O O I/O State During RSTIN# Assertion IN HV PU TRI TERM HV TERM HV PU TRI TERM PD State After RSTIN# De-assertion IN HV PU TRI TERM HV TERM HV PU TRI TRI S3 Pull-up/ Pull-down Misc. IN HV PU TRI TERM HV TERM HV PU TRI TERM PD Table 2-8. DAC Reset and S3 States (Intel® 82915G/82915GV/82915GL/82910GL GMCH only) Interface Signal Name HSYNC VSYNC RED RED# GREEN GREEN# BLUE BLUE# REFSET I/O O O O O O O O O O State During RSTIN# Assertion LV LV TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI TRI 0.5* VCCA_DAC State After RSTIN# Deassertion S3 Pull-up/ Pull-down DAC LV LV TRI TRI TRI TRI TRI TRI TRI 255 Ω 1% Resistor to Ground DDC_CLK DDC_DATA I/O I/O IN IN IN IN IN IN § Datasheet 51 Signal Description R 52 Datasheet Register Description R 3 Register Description The (G)MCH contains two sets of software accessible registers, accessed via the processor I/O address space: Control registers and internal configuration registers. • Control registers are I/O mapped into the processor I/O space that control access to PCI and PCI Express configuration space (see Section 3.4). • Internal configuration registers residing within the (G)MCH are partitioned into three logical device register sets (“logical” since they reside within a single physical device). The first register set is dedicated to Host Bridge functionality (i.e. DRAM configuration, other chipset operating parameters and optional features). The second register block is dedicated to the 82915G/82915P/82915PL (G)MCH Host-PCI Express Bridge functions (controls PCI Express interface configurations and operating parameters). The third register block is for the 82915G/82915GV/82915GL/82910GL GMCH internal graphics functions. The (G)MCH internal registers (I/O Mapped, Configuration and PCI Express Extended Configuration registers) are accessible by the processor. The registers that reside within the lower 256 bytes of each device 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 "little-endian" ordering (i.e., lower addresses contain the least significant parts of the field). Registers that reside in bytes 256 through 4095 of each device may only be accessed using memory mapped transactions in DWord (32-bit) quantities. 3.1 Register Terminology The following table shows the register-related terminology that is used. Item RO RS/WC Description Read Only bit(s). Writes to these bits have no effect. Read Set / Write Clear bit(s). These bits are set to ‘1’ when read and then will continue to remain set until written. A write of ‘1’ clears (sets to ‘0’) the corresponding bit(s) and a write of ‘0’ has no effect. Read / Write bit(s). These bits can be read and written. Read / Write Clear bit(s). These bits can be read. Internal events may set this bit. A write of ‘1’ clears (sets to ‘0’) the corresponding bit(s) and a write of ‘0’ has no effect. Read / Write Clear / Sticky bit(s). These bits can be read. Internal events may set this bit. A write of ‘1’ clears (sets to ‘0’) the corresponding bit(s) and a write of ‘0’ has no effect. Bits are not cleared by "warm" reset, but will be reset with a cold/complete reset (for PCI Express* related bits a cold reset is “Power Good Reset” as defined in the PCI Express* Specification). Read / Write / Lockable bit(s). These bits can be read and written. Additionally there is a bit (which may or may not be a bit marked R/W/L) that, when set, prohibits this bit field from being writeable (bit field becomes Read Only). Read / Write / Sticky bit(s). These bits can be read and written. Bits are not cleared by "warm" reset, but will be reset with a cold/complete reset (for PCI Express related bits a cold reset is “Power Good Reset” as defined in the PCI Express* Specification). R/W R/WC R/WC/S R/W/L R/W/S Datasheet 53 Register Description R Item R/WSC Description Read / Write Self Clear bit(s). These bits can be read and written. When the bit is ‘1’, hardware may clear the bit to ‘0’ based upon internal events, possibly sooner than any subsequent read could retrieve a ‘1’. Read / Write Self Clear / Lockable bit(s). These bits can be read and written. When the bit is ‘1’, hardware may clear the bit to ‘0’ based upon internal events, possibly sooner than any subsequent read could retrieve a ‘1’. Additionally there is a bit (which may or may not be a bit marked R/W/L) that, when set, prohibits this bit field from being writeable (bit field becomes Read Only). Read Write Clear bit(s). These bits can be read and written. However, a write of ‘1’ clears (sets to ‘0’) the corresponding bit(s) and a write of ‘0’ has no effect. Write Once bit(s). Once written, bits with this attribute become Read Only. These bits can only be cleared by a Reset. Write Only. Whose bits may be written, but will always-return zeros when read. They are used for write side effects. Any data written to these registers cannot be retrieved. Some of the (G)MCH registers described in this section contain reserved bits. These bits are labeled "Reserved”. Software must deal correctly with fields that are reserved. On reads, software must use appropriate masks to extract the defined bits and not rely on reserved bits being any particular value. On writes, software must ensure that the values of reserved bit positions are preserved. That is, the values of reserved bit positions must first be read, merged with the new values for other bit positions and then written back. Note the software does not need to perform read, merge, and write operation for the configuration address register. In addition to reserved bits within a register, the (G)MCH contains address locations in the configuration space of the Host Bridge entity that are marked either "Reserved" or “Intel Reserved”. The (G)MCH responds to accesses to “Reserved” address locations by completing the host cycle. When a “Reserved” register location is read, a zero value is returned. (“Reserved” registers can be 8-, 16-, or 32-bits in size). Writes to “Reserved” registers have no effect on the (G)MCH. Registers that are marked as “Intel Reserved” must not be modified by system software. Writes to “Intel Reserved” registers may cause system failure. Reads from “Intel Reserved” registers may return a non-zero value. Upon a Full Reset, the (G)MCH sets its entire set of internal configuration registers to predetermined default states. Some register values at reset are determined by external strapping options. The default state represents the minimum functionality feature set required to successfully bringing up the system. Hence, it does not represent the optimal system configuration. It is the responsibility of the system initialization software (usually BIOS) to properly determine the DRAM configurations, operating parameters and optional system features that are applicable, and to program the (G)MCH registers accordingly. R/WSC/L R/WC R/WO W Reserved Bits Reserved Registers Default Value 54 Datasheet Register Description R 3.2 Platform Configuration In platforms that support DMI (e.g. this (G)MCH) the configuration structure is significantly different from previous Hub architectures. The DMI physically connects the (G)MCH and the Intel ICH6; so, from a configuration standpoint, the DMI is logically PCI bus 0. As a result, all devices internal to the (G)MCH and the Intel ICH6 appear to be on PCI bus 0. The ICH6 internal LAN controller does not appear on bus 0; it appears on the external PCI bus (whose number is configurable). The system’s primary PCI expansion bus is physically attached to the Intel ICH6 and, from a configuration perspective, appears to be a hierarchical PCI bus behind a PCI-to-PCI bridge and therefore has a programmable PCI Bus number. The PCI Express Graphics Attach appears to system software to be a real PCI bus behind a PCI-to-PCI bridge that is a device resident on PCI bus 0. Note: A physical PCI bus 0 does not exist and that DMI and the internal devices in the (G)MCH and Intel ICH6 logically constitute PCI Bus 0 to configuration software. This is shown in Figure 3-1. Figure 3-1. Conceptual Chipset PCI Configuration Diagram Processor Intel ® 82915G/ 82915GV/ 82915GL/ 82915P/82915PL/82919GL (G)MCH PCI Configuration in I/O Device 1 (82915G/82915P/ 82915PL GMCH only DRAM Interface Bus 0, Device 0 Internal Graphics Bus 0, (82915G/82915GV/82915G L82910GL Device DMI PCI_Config_Dia Datasheet 55 Register Description R The (G)MCH contains the following PCI devices within a single physical component. The configuration registers for the devices are mapped as devices residing on PCI bus 0. • Device 0 – Host Bridge/DRAM Controller: Logically this appears as a PCI device residing on PCI bus 0. Device 0 contains the standard PCI header registers, PCI Express base address register, DRAM control (including thermal/throttling control), and configuration for the DMI and other (G)MCH specific registers. • Device 1– Host-PCI Express Bridge (82915G/82915P/82915PL (G)MCH only). Logically this appears as a “virtual” PCI-to-PCI bridge residing on PCI bus 0 and is compliant with PCI Express* Specification Revision 1.0a. Device 1 contains the standard PCI-to-PCI bridge registers and the standard PCI Express/PCI configuration registers (including the PCI Express memory address mapping). It also contains Isochronous and Virtual Channel controls in the PCI Express extended configuration space. • Device 2 – Internal Graphics Control (82915G/82915GV/82915GL/82910GL GMCH only). Logically, this appears as a PCI device residing on PCI bus 0. Physically, device 2 contains the configuration registers for 3D, 2D, and display functions. 56 Datasheet Register Description R Figure 3-2. Register Organization (Representative of the Intel® 82915G GMCH) PCI Express* Egress Port (RCRB) Device 2 Configuration Registers: Internal Graphics FFFh FFFh VC1 (Isochronous) Port Arbitration Controls Unused 000h DMI Root Complex Register Block (RCRB) 0FFh Mirror of bits needed by graphics driver graphics thermal controls 000h Device 1 Configuration Registers: PCI Express X16 FFFh PCI Express x16 Controls: Analog Controls Error Reporting Controls VC Controls Hot Plug/Slot Controls 0FFh Device Level Controls 000h Device 0 Configuration Registers FFFh (G)MCH-ICH6 Serial Interface (DMI) Controls: Analog Controls Error Reporting Controls VC Control (Incl. VCp) 000h PCI Express Address Range 0FFF FFFFh Accessed only by PCI Express enhanced access mechanism. 4KB block allocated for each potential device in root hierarchy. FFFh 0000 0000h Device 2 Range Device 1 Range Device 0 Range Unused 3FFFh 0FFh Device Level Controls, PAM EPBAR DMI BAR PCIEXBAR MCHBAR Device 0 MMIO Registers: (G)MCH Control Thermal Sensor PSB Analog Controls (Rcomp+) CH 0/1 Analog Controls CH 0/1 Timing Controls Ch 0/1 Throttling Ch 0/1 Oranization Arviter Controls Reg_Org_82915G 000h 0000h Note: Diagram not to scale NOTES: 1. Very high level representation. Many details omitted. 2. Inter graphics memory mapped registers are not shown. 3. Only Device 1 use PCI Express extended configuration space. 4. Device 0 and Device 2 use only standard PCI configuration space. 5. Hex numbers represent address range size and not actual locations. Table 3-1. Device Number Assignment for Internal (G)MCH Devices (G)MCH Function Host Bridge / DRAM Controller Host-to-PCI Express* Bridge (virtual P2P) (Intel 82915G/82915P/82915PL (G)MCH only) Internal Graphics Control (82915G/82915GV/82915GL/82910GL GMCH only) ® Device# Device 0 Device 1 Device 2 Datasheet 57 Register Description R 3.3 General Routing Configuration Accesses The (G)MCH supports two PCI related interfaces: DMI and PCI Express. PCI and PCI Express configuration cycles are selectively routed to one of these interfaces. The (G)MCH is responsible for routing configuration cycles to the proper interface. Configuration cycles to the Intel ICH6 internal devices and Primary PCI (including downstream devices) are routed to the Intel ICH6 via DMI. Configuration cycles to both the PCI Express Graphics PCI compatibility configuration space and the PCI Express Graphics extended configuration space are routed to the PCI Express Graphics port. A detailed description of the mechanism for translating processor I/O bus cycles to configuration cycles is described below. 3.3.1 Standard 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 (G)MCH. The configuration access mechanism makes use of the CONFIG_ADDRESS Register (at I/O address 0CF8h though 0CFBh) and CONFIG_DATA Register (at I/O address 0CFCh though 0CFFh). To reference a configuration register a DW 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 will result in the (G)MCH translating the CONFIG_ADDRESS into the appropriate configuration cycle. The (G)MCH is responsible for translating and routing the processor’s I/O accesses to the CONFIG_ADDRESS and CONFIG_DATA registers to internal (G)MCH configuration registers, DMI or PCI Express. 3.3.2 Logical PCI Bus 0 Configuration Mechanism The (G)MCH decodes the Bus Number (bits 23:16) and the Device Number fields of the CONFIG_ADDRESS register. If the Bus Number field of CONFIG_ADDRESS is 0 the configuration cycle is targeting a PCI Bus 0 device. The Host-DMI Bridge entity within the (G)MCH is hardwired as Device 0 on PCI Bus 0. The Host-PCI Express Bridge entity within the (G)MCH is hardwired as Device 1 on PCI Bus 0. The 82915G/82915GV/82915GL/82910GL GMCH’s Device 2 contains the control registers for the Integrated Graphics Controller. The Intel ICH6 decodes the Type 0 access and generates a configuration access to the selected internal device. 58 Datasheet Register Description R 3.3.3 Primary PCI and Downstream Configuration Mechanism If the Bus Number in the CONFIG_ADDRESS is non-zero, and falls outside the range claimed by the Host-PCI Express bridge (not between upper bound in device’s Subordinate Bus Number register and lower bound in device’s Secondary Bus Number register), the (G)MCH would generate a Type 1 DMI Configuration Cycle. This DMI configuration cycle will be sent over the DMI. If the cycle is forwarded to the Intel ICH6 via the DMI, the Intel ICH6 compares the non-zero Bus Number with the Secondary Bus Number and Subordinate Bus Number registers of its PCIto-PCI bridges to determine if the configuration cycle is meant for ICH6 PCI Express ports one of the Intel ICH6’s devices, the DMI, or a downstream PCI bus. Figure 3-3. DMI Type 0 Configuration Address Translation Configuration Address 31 1 30 Reserved 24 23 Bus Number 16 15 Device Number 11 10 Function 87 Double Word 21 XX 0 DMI Type 0 Configuration Address Extension OCFBh 31 1 30 Reserved 24 23 Bus Number OCFAh 16 15 Device Number OCF9h 11 10 Function 87 Double Word OCF8h 21 00 0 DMI_Typ0_Config Figure 3-4. DMI Type 1 Configuration Address Translation Configuration Address 31 1 30 Reserved 24 23 Bus Number 16 15 Device Number 11 10 Function 87 Double Word 21 XX 0 DMI Type 1 Configuration Address Extension OCFBh Reserved OCFAh OCF9h Device Number OCF8h Double Word 31 1 30 24 23 16 15 11 10 Function 87 21 00 0 Bus Number DMI_Typ1_Config Datasheet 59 Register Description R 3.3.4 PCI Express* Enhanced Configuration Mechanism PCI Express extends the configuration space to 4096 bytes per device/function as compared to 256 bytes allowed by PCI Specification, Revision 2.3. PCI Express configuration space is divided into a PCI 2.3 compatible region that consists of the first 256B of a logical device’s configuration space and a PCI Express extended region that consists of the remaining configuration space. The PCI compatible region can be accessed using either the mechanism defined in the previous section or using the enhanced PCI Express configuration access mechanism described in this section. The extended configuration registers may only be accessed using the enhanced PCI Express configuration access mechanism. To maintain compatibility with PCI configuration addressing mechanisms, system software must access the extended configuration space using 32-bit operations (32-bit aligned) only. These 32-bit operations include byte enables allowing only appropriate bytes within the DWord to be accessed. Locked transactions to the PCI Express memory mapped configuration address space are not supported. All changes made using either access mechanism are equivalent. The enhanced PCI Express configuration access mechanism uses a flat memory-mapped address space to access device configuration registers. This address space is reported by the system firmware to the operating system. The PCIEXBAR register defines the base address for the 256-MB block of addresses below top of addressable memory (currently 4 GB) for the configuration space associated with all devices and functions that are potentially a part of the PCI Express root complex hierarchy. The PCI Express Configuration Transaction Header includes an additional 4 bits (Extended Register Address[3:0]) between the Function Number and Register Address fields to provide indexing into the 4 KB of configuration space allocated to each potential device. For PCI Compatible Configuration Requests, the Extended Register Address field must be all zeros. Figure 3-5. Memory Map to PCI Express* Device Configuration Space 0xFFFFFFFh Bus 255 0xFFFFFh Device 31 0xFFFFFh Function 7 PCI Express Extended Configuration Space 0xFFFh 0x1FFFFFh Bus 1 0xFFFFFh Bus 0 0h 0xFFFFh Device 1 0x7FFFh Device 0 0xFFFFh Function 1 0x7FFFh Function 0 0xFFh PCI Compatible Config Space PCI Compatible Config Header 0x3Fh Located By PCI Express Base Address MemMap_PCIExpress Just the same as with PCI devices, each device is selected based on decoded address information that is provided as a part of the address portion of Configuration Request packets. A PCI Express device will decode all address information fields (bus, device, function, and extended address numbers) to provide access to the correct register. 60 Datasheet Register Description R To access this space (steps 1, 2, 3 are performed only once by BIOS) 1. Use the PCI compatible configuration mechanism to enable the PCI Express enhanced configuration mechanism by writing 1 to bit 31 of the DEVEN register. 2. Use the PCI compatible configuration mechanism to write an appropriate PCI Express base address into the PCIEXBAR register. 3. Calculate the host address of the register you wish to set using (PCI Express base + (bus number * 1 MB) + (device number * 32 KB) + (function number * 4 KB) + (1 B * offset within the function) = host address). 4. Use a memory write or memory read cycle to the calculated host address to write to or read from that register. 31 28 Base 27 Bus 20 19 Device 15 14 12 11 8 7 Register Number 2 1 X 0 X Function Extended Config_Write PCI Express Configuration Writes Internally the host interface unit translates writes to PCI Express extended configuration space to configurations on the backbone. Writes to extended space are posted on the FSB, but non-posted on the PCI Express* x16 Graphics Interface or DMI pins (i.e., translated to configuration writes). See the PCI Express Specification for more information on both the PCI 2.3 compatible and PCI Express enhanced configuration mechanism and transaction rules. Datasheet 61 Register Description R 3.3.5 Intel® 915x GMCH Configuration Cycle Flowchart Figure 3-6. Intel® 915x GMCH Configuration Cycle Flowchart DW I/O Write to CONFIG_ADDRES S with bit 31 = 1 I/O Read/Write to CONFIG_DATA Bus# = 0 Yes No GMCH Generates Type 1 Access to PCI Express Yes Bus# > Sec Bus Bus# ≤ Sub Bus in GMCH Dev 1 Device# = 0 Yes GMCH Claims if Function# = 0 No No Yes Bus# = Secondary Bus in GMCH Dev 1 Device# = 1 & Dev # 1 Enabled Yes GMCH Claims if Function# = 0 No No GMCH Generates MISI Type 1Configuration Cycle Device# = 2 & Dev# 2 Enabled Yes GMCH Claims if Function# = 0 No Device# = 0 Yes GMCH Generates Type 0 Accessto PCI Express Device# = 7& Dev# 7 Enabled Yes GMCH Claims if Function# = 0 No No MCH allows cycle to go to DMI resulting in Master Abort GMCH Generates DMI Type 0 Configuration Cycle Config_Cyc_Flow_915 62 Datasheet Register Description R 3.4 I/O Mapped Registers The (G)MCH 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. 3.4.1 CONFIG_ADDRESS—Configuration Address Register I/O Address: Default Value: Access: Size: 0CF8h Accessed as a DWord 00000000h R/W 32 bits CONFIG_ADDRESS is a 32-bit register that can be accessed only as a DW. A Byte or Word reference will "pass through" the Configuration Address Register and DMI onto the Primary PCI 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. Bit Access & Default R/W 0b Configuration Enable (CFGE): 1 = Enable 0 = Disable Reserved R/W 00h Bus Number: If the Bus Number is programmed to 00h the target of the Configuration Cycle is a PCI Bus #0 agent. If this is the case and the (G)MCH is not the target (i.e., the device number is ≥ 3 and not equal to 7), then a DMI Type 0 Configuration Cycle is generated. If the Bus Number is non-zero, and does not fall within the ranges enumerated by device 1’s Secondary Bus Number or Subordinate Bus Number Register, then a DMI Type 1 Configuration Cycle is generated. If the Bus Number is non-zero and matches the value programmed into the Secondary Bus Number Register of device 1, a Type 0 PCI configuration cycle will be generated on PCI Express Graphics. If the Bus Number is non-zero, greater than the value in the Secondary Bus Number register of device 1 and less than or equal to the value programmed into the Subordinate Bus Number Register of device 1 a Type 1 PCI configuration cycle will be generated on PCI Express Graphics. This field is mapped to byte 8 [7:0] of the request header format during PCI Express Configuration cycles and A[23:16] during the DMI Type 1 configuration cycles. Description 31 30:24 23:16 Datasheet 63 Register Description R Bit Access & Default R/W 00h Description 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 (G)MCH decodes the Device Number field. The (G)MCH is always Device Number 0 for the Host bridge entity, Device Number 1 for the Host-PCI Express entity. Therefore, when the Bus Number =0 and the Device Number equals 0, 1, or 2 the internal (G)MCH devices are selected. This field is mapped to byte 6 [7:3] of the request header format during PCI Express Configuration cycles and A [15:11] during the DMI configuration cycles. 10:8 R/W 000b Function Number: This field allows the configuration registers of a particular function in a multi-function device to be accessed. The (G)MCH ignores configuration cycles to its internal devices if the function number is not equal to 0 or 1. This field is mapped to byte 6 [2:0] of the request header format during PCI Express Configuration cycles and A[10:8] during the DMI configuration cycles. 7:2 R/W 00h 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 byte 7 [7:2] of the request header format during PCI Express Configuration cycles and A[7:2] during the DMI Configuration cycles. 1:0 Reserved 3.4.2 CONFIG_DATA—Configuration Data Register I/O Address: Default Value: Access: Size: 0CFCh 00000000h R/W 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 Access & Default R/W 0000 0000h Description 31:0 Configuration Data Window (CDW): If bit 31 of CONFIG_ADDRESS is 1, any I/O access to the CONFIG_DATA register will produce a configuration transaction using the contents of CONFIG_ADDRESS to determine the bus, device, function, and offset of the register to be accessed. § 64 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4 Host Bridge/DRAM Controller Registers (D0:F0) The DRAM Controller registers are in Device 0 (D0), Function 0 (F0). Warning: Address locations that are not listed are considered Reserved registers locations. Reads to Reserved registers may return non-zero values. Writes to reserved locations may cause system failures. All registers that are defined in the PCI 2.3 specification, but are not necessary or implemented in this component are not included in this document. The reserved/unimplemented space in the PCI configuration header space is not documented as such in this summary. Table 4-1. Device 0 Function 0 Register Address Map Summary Address Offset 00–01h 02–03h 04–05h 06–07h 08h 09–0Bh 0Ch 0Dh 0Eh 0F–2Bh 2C–2Dh 2E–2Fh 30–33h 34h 35–3Fh 40–43h 44–47h 48–4Bh 4C–4Fh Register Symbol VID DID PCICMD PCISTS RID CC — MLT HDR — SVID SID — CAPPTR — EPBAR MCHBAR PCIEXBAR DMIBAR Register Name Vendor Identification Device Identification PCI Command PCI Status Revision Identification Class Code Reserved Master Latency Timer Header Type Reserved Subsystem Vendor Identification Subsystem Identification Reserved Capabilities Pointer Reserved Egress Port Base Address GMCH Memory Mapped Register Range Base Address PCI Express* Register Range Base Address Root Complex Register Range Base Address Default Value 8086h 2580h 0006h 0090h See register description 060000h — 00h 00h — 0000h 0000h — EOh — 00000000h 00000000h E0000000h 00000000h Access RO RO RO, R/W RO, R/W/C RO RO — RO RO — R/W/O R/W/O — RO — RO R/W R/W R/W Datasheet 65 Host Bridge/DRAM Controller Registers (D0:F0) R Address Offset 52–53h 54–57h 58–8Fh 90h 91h 92h 93h 94h 95h 96h 97h 98–9Bh 9Ch 9Dh 9Eh 9F–C7h C8–C9h CA–CBh CC–DBh DC–DFh E0–E8h E9–FFh 100h 101h 102h 103h 104–107h 108h 109h 10A–10Bh 10Ch 10Dh Register Symbol GGC DEVEN — PAM0 PAM1 PAM2 PAM3 PAM4 PAM5 PAM6 LAC — TOLUD SMRAM ESMRAMC — ERRSTS ERRCMD — SKPD CAPID0 — C0DRB0 C0DRB1 C0DRB2 C0DRB3 — C0DRA0 C0DRA2 — C0DCLKDIS — Register Name GMCH Graphics Control Register (82915G GMCH only) Device Enable Reserved Programmable Attribute Map 0 Programmable Attribute Map 1 Programmable Attribute Map 2 Programmable Attribute Map 3 Programmable Attribute Map 4 Programmable Attribute Map 5 Programmable Attribute Map 6 Legacy Access Control Reserved Top of Low Usable DRAM System Management RAM Control Extended System Management RAM Control Reserved Error Status Error Command Reserved Scratchpad Data Capability Identifier Reserved Channel A DRAM Rank Boundary Address 0 Channel A DRAM Rank Boundary Address 1 Channel A DRAM Rank Boundary Address 2 Channel A DRAM Rank Boundary Address 3 Reserved Channel A DRAM Rank 0,1 Attribute Channel A DRAM Rank 2,3 Attribute Reserved Channel A DRAM Clock Disable Reserved Default Value 0030h 00000019h — 00h 00h 00h 00h 00h 00h 00h 00h — 08h 00h 00h — 0000h 0000h — 00000000h 0000000000 01090009h — 00h 00h 00h 00h — 00h 00h — 00h — Access R/W/L R/W — R/W R/W R/W R/W R/W R/W R/W R/W — R/W RO, R/W/L RO, R/W/L — RO, R/W/L R/W — R/W RO — R/W R/W R/W R/W — R/W R/W — R/W — 66 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R Address Offset 10E–10F 110–113h 114–117h 118–11Fh 120–123h 124–17Fh 180h 181h 182h 183h 184–187h 188h 189h 18A–18Bh 18Ch 18Dh 18E–18Fh 190–193h 194h 195–19Fh 1A0–1A3h 1A4–F0Fh F10–F13h F14h Register Symbol C0BNKARC — C0DRT1 — C0DRC0 — C1DRB0 C1DRB1 C1DRB2 C1DRB3 — C1DRA0 C1DRA2 — C1DCLKDIS — C1BNKARC — C1DRT1 — C1DRC0 — PMCFG PMSTS Register Name Channel A DRAM Bank Architecture Reserved Channel A DRAM Timing Register Reserved Channel A DRAM Controller Mode 0 Reserved Channel B DRAM Rank Boundary Address 0 Channel B DRAM Rank Boundary Address 1 Channel B DRAM Rank Boundary Address 2 Channel B DRAM Rank Boundary Address 3 Reserved Channel B DRAM Rank 0,1 Attribute Channel B DRAM Rank 2,3 Attribute Reserved Channel B DRAM Clock Disable Reserved Channel B Bank Architecture Reserved Channel B DRAM Timing Register 1 Reserved Channel B DRAM Controller Mode 0 Reserved Power Management Configuration Power Management Status Default Value 0000h — 900122h — 00000000h — 00h 00h 00h 00h — 00h 00h — 00h — 0000h — 900122h — 00000000h — 00000000h 00000000h Access R/W — R/W — R/W, RO — R/W R/W R/W R/W — R/W R/W — R/W — R/W — R/W, RO — R/W, RO — R/W R/W/C/S Datasheet 67 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1 4.1.1 Host Bridge/DRAM Controller PCI Register Details (D0:F0) VID—Vendor Identification (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 00h 8086h RO 16 bits This register combined with the Device Identification register uniquely identifies any PCI device. Bit Access & Default RO 8086h Description 15:0 Vendor Identification Number (VID): PCI standard identification for Intel. 4.1.2 DID—Device Identification (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 02h 2580h RO 16 bits This register combined with the Vendor Identification register uniquely identifies any PCI device. Bit Access & Default RO 2580h Description 15:0 Device Identification Number (DID): This field is an identifier assigned to the (G)MCH core/primary PCI device. 68 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.3 PCICMD—PCI Command (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 04h 0006h RO, R/W 16 bits Since (G)MCH Device 0 does not physically reside on Primary PCI bus, many of the bits are not implemented. Bit Access & Default Reserved RO 0b R/W 0b Fast Back-to-Back Enable (FB2B). This bit controls whether or not the master can do fast back-to-back write. Since device 0 is strictly a target this bit is not implemented and is hardwired to 0. SERR Enable (SERRE). This bit is a global enable bit for Device 0 SERR messaging. The (G)MCH does not have a SERR signal. The (G)MCH communicates the SERR condition by sending an SERR message over DMI to the ICH6. 1 = Enable. The (G)MCH is enabled to generate SERR messages over DMI for specific Device 0 error conditions that are individually enabled in the ERRCMD register. The error status is reported in the ERRSTS, and PCISTS registers. If SERRE is clear, then the SERR message is not generated by the (G)MCH for Device 0. 0 = Disable Note: That this bit only controls SERR messaging for the Device 0. Device 1 has its own SERRE bits to control error reporting for error conditions occurring in that device. The control bits are used in a logical OR manner to enable the SERR DMI message mechanism. 7 6 5 4 3 2 1 0 RO 0b RO 0b RO 0b RO 0b RO 0b RO 1b RO 1b RO 0b Address/Data Stepping Enable (ADSTEP). Hardwired to 0. Parity Error Enable (PERRE). PERR# is not implemented by the (G)MCH and this bit is hardwired to 0. VGA Palette Snoop Enable (VGASNOOP). Hardwired to a 0. Memory Write and Invalidate Enable (MWIE). The (G)MCH will never issue memory write and invalidate commands. This bit is therefore hardwired to 0. Reserved Bus Master Enable (BME). The (G)MCH is always enabled as a master. This bit is hardwired to a "1". Memory Access Enable (MAE). The (G)MCH always allows access to main memory. This bit is not implemented and is hardwired to 1. I/O Access Enable (IOAE). Hardwired to a 0. Description 15:10 9 8 Datasheet 69 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.4 PCISTS—PCI Status (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 06h 0090h RO, R/W/C 16 bits This status register reports the occurrence of error events on Device 0’s PCI interface. Since the (G)MCH Device 0 does not physically reside on Primary PCI, many of the bits are not implemented. Bit Access & Default RO 0b R/W/C 0b Description 15 14 Detected Parity Error (DPE): Hardwired to a 0. Signaled System Error (SSE): Software clears this bit by writing a 1 to it. 1 = The (G)MCH Device 0 generated an SERR message over DMI for any enabled Device 0 error condition. Device 0 error conditions are enabled in the PCICMD, and ERRCMD registers. Device 0 error flags are read/reset from the PCISTS, or ERRSTS registers. Received Master Abort Status (RMAS): Software clears this bit by writing a 1 to it. 1 = (G)MCH generated a DMI request that receives an Unsupported Request completion packet. 13 R/WC 0b 12 R/WC 0b Received Target Abort Status (RTAS): Software clears this bit by writing a 1 to it. 1 = (G)MCH generated a DMI request that receives a Completer Abort completion packet. 11 RO 0b RO 00b RO 0b RO 1b Signaled Target Abort Status (STAS): The (G)MCH will not generate a Target Abort DMI completion packet or Special Cycle. This bit is not implemented in the (G)MCH and is hardwired to a 0. DEVSEL Timing (DEVT): These bits are hardwired to "00". Device 0 does not physically connect to Primary PCI. These bits are set to "00" (fast decode) so that optimum DEVSEL timing for Primary PCI is not limited by the (G)MCH. Master Data Parity Error Detected (DPD): PERR signaling and messaging are not implemented by the (G)MCH; therefore, this bit is hardwired to 0. Fast Back-to-Back (FB2B): Hardwired to 1. Device 0 does not physically connect to Primary PCI. This bit is set to 1 (indicating fast back-to-back capability) so that the optimum setting for Primary PCI is not limited by the (G)MCH. Reserved 10:9 8 7 6 5 4 RO 0b RO 1b 66 MHz Capable: Does not apply to PCI Express*. Hardwired to 0. Capability List (CLIST): This bit is hardwired to 1 to indicate to the configuration software that this device/function implements a list of new capabilities. A list of new capabilities is accessed via register CAPPTR at configuration address offset 34h. Register CAPPTR contains an offset pointing to the start address within configuration space of this device where the Capability standard register resides. Reserved 3:0 70 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.5 RID—Revision Identification (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 08h See bit description RO 8 bits This register contains the revision number of the (G)MCH Device 0. Bit Access & Default RO 00h Description 7:0 Revision Identification Number (RID): This field indicates the number of times that this device in this component has been “stepped” through the manufacturing ® process. Refer to the Intel 82915G/82915P/82915GV/82910GL Express Chipset Specification Update for the value of the Revision ID Register. 4.1.6 CC—Class Code (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 09h 060000h RO 24 bits This register identifies the basic function of the device, a more specific sub-class, and a registerspecific programming interface. Bit Access & Default RO 06h Description 23:16 Base Class Code (BCC): This is an 8-bit value that indicates the base class code for the (G)MCH. 06h = Bridge device. 15:8 RO 00h Sub-Class Code (SUBCC): This is an 8-bit value that indicates the category of Bridge into which the (G)MCH falls. 00h = Host Bridge. 7:0 RO 00h Programming Interface (PI): This is an 8-bit value that indicates the programming interface of this device. This value does not specify a particular register set layout and provides no practical use for this device. Datasheet 71 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.7 MLT—Master Latency Timer (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 0Dh 00h RO 8 bits Device 0 in the (G)MCH is not a PCI master. Therefore, this register is not implemented. Bit Access & Default Reserved Description 7:0 4.1.8 HDR—Header Type (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 0Eh 00h RO 8 bits This register identifies the header layout of the configuration space. No physical register exists at this location. Bit Access & Default RO 00h Description 7:0 PCI Header (HDR): This field always returns 0 to indicate that the (G)MCH is a single function device with standard header layout. 4.1.9 SVID—Subsystem Vendor Identification (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 2Ch 0000h R/WO 16 bits This value is used to identify the vendor of the subsystem. Bit Access & Default R/WO 0000h Description 15:0 Subsystem Vendor ID (SUBVID): This field should be programmed during bootup to indicate the vendor of the system board. After it has been written once, it becomes read only. 72 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.10 SID—Subsystem Identification (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 2Eh 0000h R/W/O 16 bits This value is used to identify a particular subsystem. Bit Access & Default R/WO 0000h Description 15:0 Subsystem ID (SUBID): This field should be programmed during BIOS initialization. After it has been written once, it becomes read only. 4.1.11 CAPPTR—Capabilities Pointer (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 34h E0h RO 8 bits The CAPPTR provides the offset that is the pointer to the location of the first device capability in the capability list. Bit Access & Default RO E0h Description 7:0 Pointer to the offset of the first capability ID register block: In this case the first capability is the product-specific Capability Identifier (CAPID0). Datasheet 73 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.12 EPBAR—Egress Port Base Address (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 40h 00000000h RO 32 bits This is the base address for the Egress Port MMIO configuration space. There is no physical memory within this 4-KB window that can be addressed. The 4 KB reserved by this register does not alias to any PCI 2.3 compliant memory-mapped space. On reset, this register is disabled and must be enabled by writing a 1 to EPBAREN[Dev 0, offset 54h, bit 27] Bit Access & Default R/W 00000h Description 31:12 Egress Port MMIO Base Address: This field corresponds to bits 31 to 12 of the base address Egress Port MMIO configuration space. BIOS will program this register resulting in a base address for a 4-KB block of contiguous memory address space. This register ensures that a naturally aligned 4-KB space is allocated within total addressable memory space of 4 GB. System software uses this base address to program the (G)MCH MMIO register set. 11:0 Reserved 74 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.13 MCHBAR—(G)MCH Memory Mapped Register Range Base Address (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 44h 00000000h R/W 32 bits This is the base address for the (G)MCH memory-mapped configuration space. There is no physical memory within this 16-KB window that can be addressed. The 16 KB reserved by this register does not alias to any PCI 2.3 compliant memory mapped space. On reset, this register is disabled and must be enabled by writing a 1 to MCHBAREN [Dev 0, offset 54h, bit 28] Bit Access & Default R/W 00000h Description 31:14 (G)MCH Memory Mapped Base Address: This field corresponds to bits 31:14 of the base address (G)MCH memory-mapped configuration space. BIOS will program this register resulting in a base address for a 16-KB block of contiguous memory address space. This register ensures that a naturally aligned 16-KB space is allocated within total addressable memory space of 4 GB. System software uses this base address to program the (G)MCH Memorymapped register set. 13:0 Reserved Datasheet 75 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.14 PCIEXBAR—PCI Express* Register Range Base Address (D0:F0) (Intel® 82915G/82915P/82915PL Only) PCI Device: Address Offset: Default Value: Access: Size: 0 48h E0000000h R/W 32 bits This is the base address for the PCI Express configuration space. This window of addresses contains the 4 KB of configuration space for each PCI Express device that can potentially be part of the PCI Express hierarchy associated with the (G)MCH. There is not actual physical memory within this 256-MB window that can be addressed. Each PCI Express hierarchies require a PCI Express BASE register. The (G)MCH supports one PCI Express hierarchy. The 256 MB reserved by this register does not alias to any PCI 2.3 compliant memory-mapped space. For example, MCHBAR reserves a 16-KB space and reserves a 4-KB space both outside of PCIEXBAR space. They cannot be overlaid on the space reserved by PCIEXBAR for devices 0. On reset, this register is disabled and must be enabled by writing a 1 to PCIEXBAREN [Dev 0, offset 54h, bit 31] If the PCI Express Base Address [bits 31:28] were set to Fh, an overlap with the High BIOS area, APIC ranges would result. Software must guarantee that these ranges do not overlap. The PCI Express Base Address cannot be less than the maximum address written to the Top of physical memory register (TOLUD). If a system is populated with more than 3.5 GB, either the PCI Express Enhanced Access mechanism must be disabled or the value in TOLUD must be reduced to report that only 3.5 GB are present in the system to allow a value of Eh for the PCI Express Base Address (assuming that all PCI 2.3 compatible configuration space fits above 3.75 GB). Bit Access & Default R/W Eh Description 31:28 PCI Express* Base Address: This field corresponds to bits 31 to 28 of the base address for PCI Express enhanced configuration space. BIOS will program this register resulting in a base address for a 256-MB block of contiguous memory address space. Having control of those particular 4 bits insures that this base address will be on a 256-MB boundary, above the lowest 256 MB and still within total addressable memory space, currently 4 GB. The address used to access the PCI Express configuration space for a specific device can be determined as follows: PCI Express Base Address + Bus Number * 1 MB + Device Number * 32 KB + Function Number * 4 KB The address used to access the PCI Express configuration space for Device 1 in this component would be PCI Express Base Address + 0 * 1 MB + 1 * 32 KB + 0 * 4 KB = PCI Express Base Address + 32 KB. Remember that this address is the beginning of the 4-KB space that contains both the PCI compatible configuration space and the PCI Express extended configuration space. 27:0 Reserved 76 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.15 DMIBAR—Root Complex Register Range Base Address (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 4Ch 00000000h R/W 32 bits This is the base address for the Root Complex configuration space. This window of addresses contains the Root Complex Register set for the PCI Express hierarchy associated with the (G)MCH. There is no physical memory within this 4-KB window that can be addressed. The 4 KB that is reserved by this register does not alias to any PCI 2.3 compliant memory mapped space. On reset, this register is disabled and must be enabled by writing a 1 to the DMIBAREN [Dev 0, offset 54h, bit 29]. | Bit Access & Default R/W 0000 0h Description 31:12 DMI Base Address: This field corresponds to bits 31 to 12 of the base address DMI configuration space. BIOS will program this register resulting in a base address for a 4-KB block of contiguous memory address space. This register ensures that a naturally aligned 4-KB space is allocated within total addressable memory space of 4 GB. System software uses this base address to program the DMI register set. 11:0 Reserved Datasheet 77 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.16 GGC—GMCH Graphics Control Register (D0:F0) (82915G/82915GV/82915GL/82910GL GMCH only) PCI Device: Address Offset: Default Value: Access: Size: 0 52h 0030h R/W/L 16 bits Bit Access & Default Reserved R/W/L 011b Descriptions 15:7 6:4 Graphics Mode Select (GMS): This field is used to select the amount of main memory that is pre-allocated to support the Internal Graphics device in VGA (non-linear) and Native (linear) modes. The BIOS ensures that memory is preallocated only when Internal graphics is enabled. Device 2 (IGD) does not claim VGA cycles (memory and I/O), and the Sub-Class Code field within Device 2, Function 0 Class Code register is 80h. 000 = No memory pre-allocated 001 = DVMT (UMA) mode, 1 MB of memory pre-allocated for frame buffer. 010 = Reserved. 011 = DVMT (UMA) mode, 8 MB of memory pre-allocated for frame buffer. 100–111 = Reserved. NOTES: 1. This register is locked and becomes Read Only when the D_LCK bit in the SMRAM register is set. 2. If IGD is disabled, this field should be set to 000. 3:2 1 R/W 0b Reserved IGD VGA Disable (IVD): 0 = Enable. Device 2 (IGD) claims VGA memory and I/O cycles, the Sub-Class Code within Device 2 Class Code register is 00h. 1 = Disable. Device 2 (IGD) does not claim VGA cycles (Memory and I/O), and the Sub-Class Code field within Device 2, Function 0 Class Code register is 80h. 0 Reserved 78 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.17 DEVEN—Device Enable (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 54h 00000019h R/W 32 bits This register allows for enabling/disabling of PCI devices and functions that are within the (G)MCH. Bit Access & Default R/W 0b Description 31 82915G/82915P/82915PL (G)MCH: PCIEXBAR Enable (PCIEXBAREN): 0 = The PCIEXBAR register is disabled. Memory read and write transactions proceed as if there were no PCIEXBAR register. PCIEXBAR bits 31:28 are R/W with no functionality behind them. 1 = The PCIEXBAR register is enabled. Memory read and write transactions whose address bits 31:28 match PCIEXBAR 31:28 will be translated to configuration reads and writes within the (G)MCH. These translated cycles are routed as shown in the table above. 82915GV/82915GL/82910GL GMCH: Reserved. 30 29 R/W 0b Reserved DMIBAR Enable (DMIBAREN): 0 = DMIBAR is disabled and does not claim any memory. 1 = DMIBAR memory mapped accesses are claimed and decoded appropriately. 28 R/W 0b MCHBAR Enable (MCHBAREN): 0 = MCHBAR is disabled and does not claim any memory. 1 = MCHBAR memory mapped accesses are claimed and decoded appropriately. 27 R/W 0b EPBAR Enable (EPBAREN): 0 = EPBAR is disabled and does not claim any memory. 1 = EPBAR memory mapped accesses are claimed and decoded appropriately. 26:5 Reserved Datasheet 79 Host Bridge/DRAM Controller Registers (D0:F0) R Bit Access & Default R/W 1b Description 4 82915G/82915GV/82915GL/82910GL GMCH: Internal Graphics Engine Function 1 (D2F1EN): 0 = Bus 0 Device 2 Function 1 is disabled and hidden 1 = Bus 0 Device 2 Function 1 is enabled and visible Note: Setting this bit to enabled when bit 3 is 0 has no meaning. 82915P/82915PL MCH: Reserved. 3 R/W 1b 82915G/82915GV/82915GL/82910GL GMCH: Internal Graphics Engine Function 0 (D2F0EN): 0 = Bus 0 Device 2 Function 0 is disabled and hidden 1 = Bus 0 Device 2 Function 0 is enabled and visible 82915P/82915PL MCH: Reserved. 2 1 R/W 1b Strap dependent Reserved 82915G/82915P/82915PL (G)MCH: PCI Express* Port (D1EN): 0 = Bus 0 Device 1 Function 0 is disabled and hidden. This also gates PCI Express internal clock (lgclk) and asserts PCI Express internal reset (lgrstb). 1 = Bus 0 Device 1 Function 0 is enabled and visible. The SDVO Presence hardware strap determines default value. Device 1 is disabled on Reset when the SDVO Presence strap (SDVO_CTLRDATA signal) is sampled high, and is enabled otherwise. 82915GV/82915GL/82910GL GMCH: Reserved. 0 RO 1b Host Bridge: Bus 0 Device 0 Function 0 can not be disabled and is therefore hardwired to 1. 80 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.18 PAM0—Programmable Attribute Map 0 (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 90h 00h R/W 8 bits This register controls the read, write, and shadowing attributes of the BIOS area from 0F0000h– 0FFFFFh The (G)MCH allows programmable memory attributes on 13 Legacy memory segments of various sizes in the 768-KB to 1-MB address range. Seven Programmable Attribute Map (PAM) Registers are used to support these features. Cache ability of these areas is controlled via the MTRR registers in the processor. Two bits are used to specify memory attributes for each memory segment. These bits apply to both host accesses and PCI initiator accesses to the PAM areas. These attributes are: • RE (Read Enable). When RE = 1, the processor read accesses to the corresponding memory segment are claimed by the (G)MCH and directed to main memory. Conversely, when RE = 0, the host read accesses are directed to Primary PCI. • WE (Write Enable). When WE = 1, the host write accesses to the corresponding memory segment are claimed by the (G)MCH and directed to main memory. Conversely, when WE = 0, the host write accesses are directed to Primary PCI. The RE and WE attributes permit a memory segment to be Read Only, Write Only, Read/Write, or disabled. For example, if a memory segment has RE = 1 and WE = 0, the segment is Read Only. Each PAM Register controls two regions, typically 16 KB in size. Bit Access & Default Reserved R/W 00b Description 7:6 5:4 0F0000-0FFFFF Attribute (HIENABLE): This field controls the steering of read and write cycles that addresses the BIOS area from 0F0000h to 0FFFFFh. 00 = DRAM Disabled: All accesses are directed to the DMI. 01 = Read Only: All reads are sent to DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. 3:0 Reserved Warning: The (G)MCH may hang if a PCI Express graphics attach or DMI originated access to Read Disabled or Write Disabled PAM segments occurs (due to a possible IWB to non-DRAM). For these reasons the following critical restriction is placed on the programming of the PAM regions: At the time that a DMI or PCI Express graphics attach accesses to the PAM region may occur, the targeted PAM segment must be programmed to be both readable and writeable. Datasheet 81 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.19 PAM1—Programmable Attribute Map 1 (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 91h 00h R/W 8 bits This register controls the read, write, and shadowing attributes of the BIOS areas from 0C0000h– 0C7FFFh. Bit Access & Default Reserved R/W 00b 0C4000-0C7FFF Attribute (HIENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0C4000h to 0C7FFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. 3:2 1:0 R/W 00b Reserved 0C0000-0C3FFF Attribute (LOENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0C0000h to 0C3FFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. Description 7:6 5:4 82 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.20 PAM2—Programmable Attribute Map 2 (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 92h 00h R/W 8 bits This register controls the read, write, and shadowing attributes of the BIOS areas from 0C8000h– 0CFFFFh. Bit Access & Default Reserved R/W 00b 0CC000h–0CFFFFh Attribute (HIENABLE): 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. 3:2 1:0 R/W 00b Reserved 0C8000h–0CBFFFh Attribute (LOENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0C8000h to 0CBFFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. Description 7:6 5:4 Datasheet 83 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.21 PAM3—Programmable Attribute Map 3 (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 93h 00h R/W 8 bits This register controls the read, write, and shadowing attributes of the BIOS areas from 0D0000h– 0D7FFFh. Bit Access & Default Reserved R/W 00b 0D4000h–0D7FFFh Attribute (HIENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0D4000h to 0D7FFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. 3:2 1:0 R/W 00b Reserved 0D0000h–0D3FFFh Attribute (LOENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0D0000h to 0D3FFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. Description 7:6 5:4 84 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.22 PAM4—Programmable Attribute Map 4 (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 94h 00h R/W 8 bits This register controls the read, write, and shadowing attributes of the BIOS areas from 0D8000h0DFFFFh. Bit Access & Default Reserved R/W 00b 0DC000h–0DFFFFh Attribute (HIENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0DC000h to 0DFFFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. 3:2 1:0 R/W 00b Reserved 0D8000h–0DBFFFh Attribute (LOENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0D8000h to 0DBFFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. Description 7:6 5:4 Datasheet 85 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.23 PAM5—Programmable Attribute Map 5 (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 95h 00h R/W 8 bits This register controls the read, write, and shadowing attributes of the BIOS areas from 0E0000h0E7FFFh. Bit Access & Default Reserved R/W 00b 0E4000h–0E7FFFh Attribute (HIENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0E4000h to 0E7FFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. 3:2 1:0 R/W 00b Reserved 0E0000h–0E3FFFh Attribute (LOENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0E0000h to 0E3FFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. Description 7:6 5:4 86 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.24 PAM6—Programmable Attribute Map 6 (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 96h 00h R/W 8 bits This register controls the read, write, and shadowing attributes of the BIOS areas from 0E8000h– 0EFFFFh. Bit Access & Default Reserved R/W 00b 0EC000h–0EFFFFh Attribute (HIENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0E4000h to 0E7FFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. 3:2 1:0 R/W 00b Reserved 0E8000h–0EBFFFh Attribute (LOENABLE): This field controls the steering of read and write cycles that address the BIOS area from 0E0000h to 0E3FFFh. 00 = DRAM Disabled: Accesses are directed to the DMI. 01 = Read Only: All reads are serviced by DRAM. All writes are forwarded to the DMI. 10 = Write Only: All writes are sent to DRAM. Reads are serviced by DMI. 11 = Normal DRAM Operation: All reads and writes are serviced by DRAM. Description 7:6 5:4 Datasheet 87 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.25 LAC—Legacy Access Control (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 97h 00h R/W 8 bits This 8-bit register controls a fixed DRAM hole from 15–16 MB. Bit Access & Default R/W 0b Description 7 Hole Enable (HEN): This field enables a memory hole in DRAM space. The DRAM that lies "behind" this space is not remapped. 0 = No memory hole. 1 = Memory hole from 15 MB to 16 MB. 6:1 0 R/W 0b Reserved MDA Present (MDAP): This bit works with the VGA Enable bits in the BCTRL register of Device 1 to control the routing of processor initiated transactions targeting MDA compatible I/O and memory address ranges. This bit should not be set if device 1's VGA Enable bit is not set. If device 1's VGA enable bit is not set, then accesses to I/O address range x3BCh– x3BFh are forwarded to the DMI. If the VGA enable bit is set and MDA is not present, then accesses to I/O address range x3BCh–x3BFh are forwarded to PCI Express* if the address is within the corresponding IOBASE and IOLIMIT, otherwise they are forwarded to the DMI. MDA resources are defined as the following: Memory: I/O: 0B0000h – 0B7FFFh 3B4h, 3B5h, 3B8h, 3B9h, 3BAh, 3BFh, (Including ISA address aliases, A [15:10] are not used in decode) Any I/O reference that includes the I/O locations listed above, or their aliases, will be forwarded to the DMI even if the reference includes I/O locations not listed above. The following table shows the behavior for all combinations of MDA and VGA: VGAEN 0 0 1 1 MDAP 0 1 0 1 Description All References to MDA and VGA space are routed to the DMI Illegal combination All VGA and MDA references are routed to PCI Express Graphics Attach. All VGA references are routed to PCI Express Graphics Attach. MDA references are routed to the DMI 88 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.26 TOLUD—Top of Low Usable DRAM (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 9Ch 08h R/W 8 bits This 8-bit register defines the Top of Low Usable DRAM. TSEG and Graphics Stolen Memory (82915G only) are within the DRAM space defined. From the top, the (G)MCH optionally claims 1 to 32 MB of DRAM for internal graphics if enabled (82915G/82915GV/82915GL/82910GL GMCH only), and 1, 2, or 8 MB of DRAM for TSEG if enabled. These bits are LT Lockable. Bit Access & Default R/W 01h Description 7:3 Top of Low Usable DRAM (TOLUD): This register contains bits 31:27 of an address one byte above the maximum DRAM memory that is usable by the operating system. Address bits 31:27 programmed to 01h implies a minimum memory size of 128 MBs. Configuration software must set this value to the smaller of the following 2 choices: • Maximum amount memory in the system plus one byte or the minimum address allocated for PCI memory. Address bits 26:0 are assumed to be 000_0000h for the purposes of address comparison. The host interface positively decodes an address towards DRAM if the incoming address is less than the value programmed in this register. If this register is set to 0000 0b, it implies 128 MBs of system memory. Note: The Top of Low Usable DRAM is the lowest address above both Graphics Stolen memory (82915G/82915GV/82915GL/82910GL only) and TSEG. The host interface determines the base of Graphics Stolen Memory by subtracting the Graphics Stolen Memory Size from TOLUD and further decrements by 1 MB to determine base of TSEG. 2:0 Reserved Programming Example (82915G/82915GV/82915GL/82910GL GMCH only): • C1DRB7 is set to 4 GB • TSEG is enabled and TSEG size is set to 1 MB • Internal Graphics is enabled and Graphics Mode Select is set to 32 MB • BIOS knows the OS requires 1G of PCI space. BIOS also knows the range from FEC0_0000h to FFFF_FFFFh is not usable by the system. This 20-MB range at the very top of addressable memory space is lost to APIC. According to the above equation, TOLUD is originally calculated to: 4 GB = 1_0000_0000h The system memory requirements are: 4 GB (max addressable space) – 1 GB (PCI space) – 20 MB (lost memory) = 3 GB – 128 MB (minimum granularity) = B800_0000h Since B800_0000h (PCI and other system requirements) is less than 1_0000_0000h, TOLUD should be programmed to B8h. Datasheet 89 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.27 SMRAM—System Management RAM Control (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 9Dh 00h R/W/L, RO 8 bits The SMRAMC register controls how accesses to Compatible and Extended SMRAM spaces are treated. The Open, Close, and Lock bits function only when G_SMRAME bit is set to a 1. Also, the OPEN bit must be reset before the LOCK bit is set. Bit Access & Default Reserved R/W/L 0b SMM Space Open (D_OPEN): When D_OPEN=1 and D_LCK=0, the SMM space DRAM is made visible even when SMM decode is not active. This is intended to help BIOS initialize SMM space. Software should ensure that D_OPEN=1 and D_CLS=1 are not set at the same time. SMM Space Closed (D_CLS): When D_CLS = 1 SMM space DRAM is not accessible to data references, even if SMM decode is active. Code references may still access SMM space DRAM. This will allow SMM software to reference through SMM space to update the display even when SMM is mapped over the VGA range. Software should ensure that D_OPEN=1 and D_CLS=1 are not set at the same time. Note that the D_CLS bit only applies to Compatible SMM space. SMM Space Locked (D_LCK): When D_LCK is set to 1, D_OPEN is reset to 0 and D_LCK, D_OPEN, C_BASE_SEG, H_SMRAM_EN, TSEG_SZ and TSEG_EN become read only. D_LCK can be set to 1 via a normal configuration space write but can only be cleared by a full Reset. The combination of D_LCK and D_OPEN provide convenience with security. The BIOS can use the D_OPEN function to initialize SMM space and then use D_LCK to "lock down" SMM space in the future so that no application software (or BIOS itself) can violate the integrity of SMM space, even if the program has knowledge of the D_OPEN function. Global SMRAM Enable (G_SMRAME): If set to a 1, Compatible SMRAM functions are enabled, providing 128 KB of DRAM accessible at the A0000h address while in SMM (ADSB with SMM decode). To enable Extended SMRAM function this bit has be set to 1. Refer to the section on SMM for more details. Once D_LCK is set, this bit becomes read only. Compatible SMM Space Base Segment (C_BASE_SEG): This field indicates the location of SMM space. SMM DRAM is not remapped. It is simply made visible if the conditions are right to access SMM space, otherwise the access is forwarded to DMI. Since the (G)MCH supports only the SMM space between A0000h and BFFFFh, this field is hardwired to 010. Description 7 6 5 R/W/L 0b 4 R/W/L 0b 3 R/W/L 0b 2:0 RO 010b 90 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.28 ESMRAMC—Extended System Management RAM Control (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 9Eh 00h R/W/L, RO 8 bits The Extended SMRAM register controls the configuration of Extended SMRAM space. The Extended SMRAM (E_SMRAM) memory provides a write-back cacheable SMRAM memory space that is above 1 MB. Bit Access & Default R/W/L 0b Description 7 Enable High SMRAM (H_SMRAME): This bit controls the SMM memory space location (i.e., above 1 MB or below 1 MB). When G_SMRAME is 1 and H_SMRAME is 1, the high SMRAM memory space is enabled. SMRAM accesses within the range 0FEDA0000h to 0FEDBFFFFh are remapped to DRAM addresses within the range 000A0000h to 000BFFFFh. Once D_LCK has been set, this bit becomes read only. Invalid SMRAM Access (E_SMERR): This bit is set when the processor has accessed the defined memory ranges in Extended SMRAM (High Memory and Tsegment) while not in SMM space and with the D-OPEN bit = 0. It is software’s responsibility to clear this bit. The software must write a 1 to this bit to clear it. SMRAM Cacheable (SM_CACHE): This bit is forced to 1 by the (G)MCH . L1 Cache Enable for SMRAM (SM_L1): This bit is forced to 1 by the (G)MCH. L2 Cache Enable for SMRAM (SM_L2): This bit is forced to 1 by the (G)MCH. TSEG Size (TSEG_SZ): This field selects the size of the TSEG memory block if enabled. Memory from the top of DRAM space is partitioned away so that it may only be accessed by the processor interface and only then when the SMM bit is set in the request packet. Non-SMM accesses to this memory region are sent to the DMI when the TSEG memory block is enabled. 00 = 1-MB Tseg. (TOLUD – Graphics Stolen Memory Size – 1M) to (TOLUD – Graphics Stolen Memory Size). 01 = 2-MB Tseg (TOLUD – Graphics Stolen Memory Size – 2M) to (TOLUD – Graphics Stolen Memory Size). 10 = 8-MB Tseg (TOLUD – Graphics Stolen Memory Size – 8M) to (TOLUD – Graphics Stolen Memory Size). 11 = Reserved. Once D_LCK has been set, these bits become read only. NOTE: References to Graphics Stolen Memory only apply to the 82915G/82915GV/82915GL/82910GL GMCH only. 6 R/W/C 0b 5 4 3 2:1 RO 1b RO 1b RO 1b R/W/L 00b 0 R/W/L 0b TSEG Enable (T_EN): This bit Enables SMRAM memory for Extended SMRAM space only. When G_SMRAME =1 and TSEG_EN = 1, the TSEG is enabled to appear in the appropriate physical address space. Note that once D_LCK is set, this bit becomes read only. Datasheet 91 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.29 ERRSTS—Error Status (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 C8h 0000h R/WC/S, RO 16 bits This register is used to report various error conditions via the SERR DMI messaging mechanism. A SERR DMI message is generated on a zero to one transition of any of these flags (if enabled by the ERRCMD and PCICMD registers). These bits are set regardless of whether or not the SERR is enabled and generated. After the error processing is complete, the error logging mechanism can be unlocked by clearing the appropriate status bit by software writing a 1 to it. 0Bit Access & Default Reserved R/WC/S 0b R/WC/S 0b (G)MCH Software Generated Event for SMI: 1 = This bit indicates the source of the SMI was a Device 2 Software Event. (G)MCH Thermal Sensor Event for SMI/SCI/SERR: This bit indicates that a (G)MCH Thermal Sensor trip has occurred and an SMI, SCI, or SERR has been generated. The status bit is set only if a message is sent based on Thermal event enables in Error command, SMI command, and SCI command registers. A trip point can generate one of SMI, SCI, or SERR interrupts (two or more per event is illegal). Multiple trip points can generate the same interrupt, if software chooses this mode, subsequent trips may be lost. If this bit is already set, an interrupt message will not be sent on a new thermal sensor event. Reserved R/WC/S 0b LOCK to non-DRAM Memory Flag (LCKF): 1 = (G)MCH detected a lock operation to memory space that did not map into DRAM. Received Refresh Timeout Flag(RRTOF): 1 = 1024 memory core refreshes are enqueued. Reserved Description 15:13 12 11 10 9 8 R/WC/S 0b 7:0 92 Datasheet Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.30 ERRCMD—Error Command (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 CAh 0000h R/W 16 bits This register controls the (G)MCH responses to various system errors. Since the (G)MCH does not have an SERR# signal, SERR messages are passed from the (G)MCH to the Intel ICH6 over DMI. When a bit in this register is set, a SERR message will be generated on DMI when the corresponding flag is set in the ERRSTS register. The actual generation of the SERR message is globally enabled for Device 0 via the PCI Command register. Bit Access & Default Reserved R/W 0b SERR on (G)MCH Thermal Sensor Event (TSESERR) 1 = The (G)MCH generates a DMI SERR special cycle when bit 11 of the ERRSTS is set. The SERR must not be enabled at the same time as the SMI for the same thermal sensor event. 0 = Reporting of this condition via SERR messaging is disabled. 10 9 R/W 0b Reserved SERR on LOCK to non-DRAM Memory (LCKERR) 1 = The (G)MCH will generate a DMI SERR special cycle whenever a processor lock cycle is detected that does not hit DRAM. 0 = Reporting of this condition via SERR messaging is disabled. 8 R/W 0b SERR on DRAM Refresh Timeout (DRTOERR) 1 = The (G)MCH generates a DMI SERR special cycle when a DRAM Refresh timeout occurs. 0 = Reporting of this condition via SERR messaging is disabled. 7:0 Reserved Description 15:12 11 Datasheet 93 Host Bridge/DRAM Controller Registers (D0:F0) R 4.1.31 SKPD—Scratchpad Data (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 DCh 00000000h R/W 32 bits This register holds 32 writable bits with no functionality behind them. It is for the convenience of BIOS and graphics drivers. Bit Access & Default R/W 00000000 h Description 31:0 Scratchpad Data: 1 DWord of data storage. 4.1.32 CAPID0—Capability Identifier (D0:F0) PCI Device: Address Offset: Default Value: Access: Size: 0 E0h 000000000001090009h RO 72 bits Bit Access & Default Reserved RO 1h RO 09h RO 00h RO 09h Description 71:28 27:24 23:16 15:8 7:0 CAPID Version: This field has the value 0001b to identify the first revision of the CAPID register definition. CAPID Length: This field has the value 09h to indicate the structure length (9 bytes). Next Capability Pointer: This field is hardwired to 00h indicating the end of the capabilities linked list. CAP_ID: This field has the value 1001b to identify the CAP_ID assigned by the PCI SIG for vendor dependent capability pointers. § 94 Datasheet MCHBAR Registers R 5 MCHBAR Registers These registers are offset from the MCHBAR base address. Address Offset 100h 101h 102h 103h 104–107h 108h 109h 10A–10Bh 10Ch 10Dh 10E–10F 110–113h 114–117h 118–11Fh 120–123h 124–17Fh 180h 181h 182h 183h 184–187h 188h 189h 18A–18Bh 18Ch 18Dh 18E–18Fh 190–193h 194h Register Symbol C0DRB0 C0DRB1 C0DRB2 C0DRB3 — C0DRA0 C0DRA2 — C0DCLKDIS — C0BNKARC — C0DRT1 — C0DRC0 — C1DRB0 C1DRB1 C1DRB2 C1DRB3 — C1DRA0 C1DRA2 — C1DCLKDIS — C1BNKARC — C1DRT1 Register Name Channel A DRAM Rank Boundary Address 0 Channel A DRAM Rank Boundary Address 1 Channel A DRAM Rank Boundary Address 2 Channel A DRAM Rank Boundary Address 3 Reserved Channel A DRAM Rank 0,1 Attribute Channel A DRAM Rank 2,3 Attribute Reserved Channel A DRAM Clock Disable Reserved Channel A DRAM Bank Architecture Reserved Channel A DRAM Timing Register Reserved Channel A DRAM Controller Mode 0 Reserved Channel B DRAM Rank Boundary Address 0 Channel B DRAM Rank Boundary Address 1 Channel B DRAM Rank Boundary Address 2 Channel B DRAM Rank Boundary Address 3 Reserved Channel B DRAM Rank 0,1 Attribute Channel B DRAM Rank 2,3 Attribute Reserved Channel B DRAM Clock Disable Reserved Channel B Bank Architecture Reserved Channel B DRAM Timing Register 1 Default Value 00h 00h 00h 00h — 00h 00h — 00h — 0000h — 900122h — 00000000h — 00h 00h 00h 00h — 00h 00h — 00h — 0000h — 900122h Access R/W R/W R/W R/W — R/W R/W — R/W — R/W — R/W — R/W, RO — R/W R/W R/W R/W — R/W R/W — R/W — R/W — R/W, RO Datasheet 95 MCHBAR Registers R Address Offset 195–19Fh 1A0–1A3h 1A4–F0Fh F10–F13h F14h Register Symbol — C1DRC0 — PMCFG PMSTS Reserved Register Name Default Value — 00000000h — 00000000h 00000000h Access — R/W, RO — R/W R/W/C/S Channel B DRAM Controller Mode 0 Reserved Power Management Configuration Power Management Status 5.1 5.1.1 MCHBAR Register Details C0DRB0—Channel A DRAM Rank Boundary Address 0 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 100h 00h R/W 8 bits The DRAM Rank Boundary Register defines the upper boundary address of each DRAM rank with a granularity of 32 MB. Each rank has its own single-byte DRB register. These registers are used to determine which chip select will be active for a given address. Channel and Rank Map: Channel A Rank 0: Channel A Rank 1: Channel A Rank 2: Channel A Rank 3: Channel B Rank 0: Channel B Rank 1: Channel B Rank 2: Channel B Rank 3: 100h 101h 102h 103h 180h 181h 182h 183h Single Channel or Asymmetric Channels Example If the channels are independent, addresses in Channel B should begin where addresses in Channel A left off, and the address of the first rank of Channel A can be calculated from the technology (256 Mbit, 512 Mbit, or 1 Gbit) and the x8 or x16 configuration. With independent channels, a value of 01h in C0DRB0 indicates that 32 MB of DRAM has been populated in the first rank, and the top address in that rank is 32 MB. 96 Datasheet MCHBAR Registers R Programming guide If Channel A is empty, all of the C0DRBs are programmed with 00h. C0DRB0 = Total memory in chA rank0 (in 32-MB increments) C0DRB1 = Total memory in chA rank0 + chA rank1 (in 32-MB increments) ______ C1DRB0 = Total memory in chA rank0 + chA rank1 + chA rank2 + chA rank3 + chB rank0 (in 32-MB increments) If Channel B is empty, all of the C1DRBs are programmed with the same value as C0DRB3. Interleaved Channels Example If channels are interleaved, corresponding ranks in opposing channels will contain the same value, and the value programmed takes into account the fact that twice as many addresses are spanned by this rank compared to the single channel case. With interleaved channels, a value of 01h in C0DRB0 and a value of 01h in C1DRB0 indicate that 32 MB of DRAM has been populated in the first rank of each channel and the top address in that rank of either channel is 64 MB. Programming guide: C0DRB0 = C1DRB0 = Total memory in chA rank0 (in 32-MB increments) C0DRB1 = C1DRB1 = Total memory in chA rank0 + chA rank1 (in 32-MB increments) ______ C0DRB3 = C1DRB3 = Total memory in chA rank0 + chA rank1+ chA rank2 + chA rank3 (in 32-MB increments) Note: Channel A DRB3 and Channel B DRB3 must be equal for this mode, but the other DRBs may be different. In all modes, if a DIMM is single sided, it appears as a populated rank and an empty rank. A DRB must be programmed appropriately for each. Each Rank is represented by a byte. Each byte has the following format. Bit Access & Default R/W 00h Description 7:0 Channel A DRAM Rank Boundary Address: This 8 bit value defines the upper and lower addresses for each DRAM rank. Bits 6:2 are compared against Address 31:27 to determine the upper address limit of a particular rank. Bits 1:0 must be 0s. Bit 7 may be programmed to a 1 in the highest DRB (DRB3) if 4 GBs of memory is present. Datasheet 97 MCHBAR Registers R 5.1.2 C0DRB1—Channel A DRAM Rank Boundary Address 1 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 101h 00h R/W 8 bits The operation of this register is detailed in the description for register C0DRB0. 5.1.3 C0DRB2—Channel A DRAM Rank Boundary Address 2 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 102h 00h R/W 8 bits The operation of this register is detailed in the description for register C0DRB0. 5.1.4 C0DRB3—Channel A DRAM Rank Boundary Address 3 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 103h 00h R/W 8 bits The operation of this register is detailed in the description for register C0DRB0. 98 Datasheet MCHBAR Registers R 5.1.5 C0DRA0—Channel A DRAM Rank 0,1 Attribute MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 108h 00h R/W 8 bits The DRAM Rank Attribute Registers define the page sizes to be used when accessing different ranks. These registers should be left with their default value (all zeros) for any rank that is unpopulated, as determined by the corresponding CxDRB registers. Each byte of information in the CxDRA registers describes the page size of a pair of ranks. Channel and Rank Map: Channel A Rank 0, 1: Channel A Rank 2, 3: Channel B Rank 0, 1: Channel B Rank 2, 3: Bit Access & Default Reserved R/W 000b Channel A DRAM odd Rank Attribute: This 3 bit field defines the page size of the corresponding rank. 000 = Unpopulated 001 = Reserved 010 = 4 KB 011 = 8 KB 100 = 16 KB Others = Reserved 3 2:0 R/W 000b Reserved Channel A DRAM even Rank Attribute: This 3 bit field defines the page size of the corresponding rank. 000 = Unpopulated 001 = Reserved 010 = 4 KB 011 = 8 KB 100 = 16 KB Others = Reserved 108h 109h 188h 189h Description 7 6:4 5.1.6 C0DRA2—Channel A DRAM Rank 2,3 Attribute MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 109h 00h R/W 8 bits The operation of this register is detailed in the description for register C0DRA0. Datasheet 99 MCHBAR Registers R 5.1.7 C0DCLKDIS—Channel A DRAM Clock Disable MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 10Ch 00h R/W 8 bits This register can be used to disable the system memory clock signals to each DIMM slot. This can significantly reduce EMI and Power concerns for clocks that go to unpopulated DIMMs. Clocks should be enabled based on whether a slot is populated, and what kind of DIMM is present. Bit Access & Default Reserved R/W 0b DIMM Clock Gate Enable Pair 5 0 = Tri-state the corresponding clock pair. 1 = Enable the corresponding clock pair. DIMM Clock Gate Enable Pair 4 0 = Tri-state the corresponding clock pair. 1 = Enable the corresponding clock pair. DIMM Clock Gate Enable Pair 3 0 = Tri-state the corresponding clock pair. 1 = Enable the corresponding clock pair. DIMM Clock Gate Enable Pair 2 0 = Tri-state the corresponding clock pair. 1 = Enable the corresponding clock pair. DIMM Clock Gate Enable Pair 1 0 = Tri-state the corresponding clock pair. 1 = Enable the corresponding clock pair. DIMM Clock Gate Enable Pair 0 0 = Tri-state the corresponding clock pair. 1 = Enable the corresponding clock pair. Description 7:6 5 4 R/W 0b 3 R/W 0b 2 R/W 0b 1 R/W 0b 0 R/W 0b Note: Since there are multiple clock signals assigned to each Rank of a DIMM, it is important to clarify exactly which Rank width field affects which clock signal: Channel 0 0 1 1 Rank 0 or 1 2 or 3 0 or 1 2 or 3 Clocks Affected SCLK_A[2:0]/ SCLK_A[2:0]# SCLK_A[5:3]/ SCLK_A[5:3]# SCLK_B[2:0]/ SCLK_B[2:0]# SCLK_B[5:3]/ SCLK_B[5:3]# 100 Datasheet MCHBAR Registers R 5.1.8 C0BNKARC—Channel A DRAM Bank Architecture MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 10Eh 0000h R/W 16 bits This register is used to program the bank architecture for each Rank. Bit Access & Default Reserved R/W 00b Rank 3 Bank Architecture 00 = 4 Bank. 01 = 8 Bank. 1X = Reserved 5:4 R/W 00b Rank 2 Bank Architecture 00 = 4 Bank. 01 = 8 Bank. 1X = Reserved 3:2 R/W 00b Rank 1 Bank Architecture 00 = 4 Bank. 01 = 8 Bank. 1X = Reserved 1:0 R/W 00b Rank 0 Bank Architecture 00 = 4 Bank. 01 = 8 Bank. 1X = Reserved Description 15:8 7:6 Datasheet 101 MCHBAR Registers R 5.1.9 C0DRT1—Channel A DRAM Timing Register MMIO Range: Address Offset: Default Value: Access: Size: Bit Access & Default Reserved R/W 9h Activate to Precharge delay (tRAS). This bit controls the number of DRAM clocks for tRAS. Minimum recommendations are beside their corresponding encodings. 0h – 3h = Reserved 4h – Fh = Four to Fifteen Clocks respectively. 19 RO 0b Reserved for Activate to Precharge Delay (tRAS) MAX: It is required that the Panic Refresh timer be set to a value less than the tRAS maximum. Based on this setting, a Panic Refresh occurs before TRAS maximum expiration and closes all the banks. This bit controls the maximum number of clocks that a DRAM bank can remain open. After this time period, the DRAM controller will guarantee to pre-charge the bank. This time period may or may not be set to overlap with time period that requires a refresh to happen. The DRAM controller includes a separate tRAS-MAX counter for every supported bank. With a maximum of four ranks, and four banks per rank, there are 16 counters per channel. 0 = 120 microseconds 1 = Reserved Note: This register will become Read Only with a value of 0 if the design does not implement these counters. tRAS-MAX is not required because a panic refresh will close all banks in a rank before tRAS-MAX expires. 18:10 9:8 R/W 01b Reserved CASB Latency (tCL). This value is programmable on DDR2 DIMMs. The value programmed here must match the CAS Latency of every DDR2 DIMM in the system. Encoding 00 01 10 11 7 Reserved DDR CL 3 2.5 2 Reserved DDR2 CL 5 4 3 Reserved MCHBAR 114h 900122hh R/W, RO 32 bits Description 31:24 23:20 102 Datasheet MCHBAR Registers R Bit Access & Default R/W 010b Description 6:4 DRAM RAS to CAS Delay (tRCD). This bit controls the number of clocks inserted between a row activate command and a read or write command to that row. 000 = 2 DRAM clocks 001 = 3 DRAM clocks 010 = 4 DRAM clocks 011 = 5 DRAM clocks 100 – 111 = Reserved 3 2:0 R/W 010b Reserved DRAM RAS Precharge (tRP). This bit controls the number of clocks that are inserted between a row precharge command and an activate command to the same rank. 000 = 2 DRAM clocks 001 = 3 DRAM clocks 010 = 4 DRAM clocks 011 = 5 DRAM clocks 100 – 111 = Reserved Datasheet 103 MCHBAR Registers R 5.1.10 C0DRC0—Channel A DRAM Controller Mode 0 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 120h 00000000h R/W 32 bits Bit 31:30 29 Access & Default Reserved R/W 0b Description Initialization Complete (IC): This bit is used for communication of software state between the memory controller and the BIOS. BIOS sets this bit to 1 after initialization of the DRAM memory array is complete. Reserved 28:11 10:8 R/W 000b Refresh Mode Select (RMS): This field determines whether refresh is enabled and, if so, at what rate refreshes will be executed. 000 = Refresh disabled 001 = Refresh enabled. Refresh interval 15.6 µsec 010 = Refresh enabled. Refresh interval 7.8 µsec 011 = Refresh enabled. Refresh interval 3.9 µsec 100 = Refresh enabled. Refresh interval 1.95 µsec 111 = Refresh enabled. Refresh interval 64 clocks (fast refresh mode) Other = Reserved 7 RO 0b Reserved 104 Datasheet MCHBAR Registers R Bit 6:4 Access & Default R/W 000 b Description Mode Select (SMS). These bits select the special operational mode of the DRAM interface. The special modes are intended for initialization at power up. 000 = Post Reset state – When the (G)MCH exits reset (power-up or otherwise), the mode select field is cleared to “000”. During any reset sequence, while power is applied and reset is active, the (G)MCH de-asserts all CKE signals. After internal reset is de-asserted, CKE signals remain de-asserted until this field is written to a value different than “000”. On this event, all CKE signals are asserted. During suspend, (G)MCH internal signal triggers DRAM controller to flush pending commands and enter all ranks into Self-Refresh mode. As part of resume sequence, (G)MCH will be reset – which will clear this bit field to “000” and maintain CKE signals de-asserted. After internal reset is deasserted, CKE signals remain de-asserted until this field is written to a value different than “000”. On this event, all CKE signals are asserted. During entry to other low power states (C3, S1), (G)MCH internal signal triggers DRAM controller to flush pending commands and enter all ranks into Self-Refresh mode. During exit to normal mode, (G)MCH signal triggers DRAM controller to exit Self-Refresh and resume normal operation without S/W involvement. 001 = NOP Command Enable – All processor cycles to DRAM result in a NOP command on the DRAM interface. 010 = All Banks Pre-charge Enable – All processor cycles to DRAM result in an “all banks precharge” command on the DRAM interface. 011 = Mode Register Set Enable – All processor cycles to DRAM result in a “mode register” set command on the DRAM interface. Host address lines are mapped to DRAM address lines in order to specify the command sent. Host address lines [12:3] are mapped to MA[9:0], and HA[13] is mapped to MA[11]. 101 = Reserved 110 = CBR Refresh Enable – In this mode all processor cycles to DRAM result in a CBR cycle on the DRAM interface 111 = Normal operation 3:2 1:0 RO Reserved DRAM Type (DT). This field is used to select between supported SDRAM types. This bit is controlled by the MTYPE strap signal. 00 = Reserved 01 = Dual Data Rate (DDR) SDRAM 10 = Second Revision Dual Data Rate (DDR2) SDRAM 11 = Reserved Datasheet 105 MCHBAR Registers R 5.1.11 C1DRB0—Channel B DRAM Rank Boundary Address 0 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 180h 00h R/W 8 bits The operation of this register is detailed in the description for register C0DRB0. 5.1.12 C1DRB1—Channel B DRAM Rank Boundary Address 1 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 181h 00h R/W 8 bits The operation of this register is detailed in the description for register C0DRB0. 5.1.13 C1DRB2—Channel B DRAM Rank Boundary Address 2 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 182h 00h R/W 8 bits The operation of this register is detailed in the description for register C0DRB0. 5.1.14 C1DRB3—Channel B DRAM Rank Boundary Address 3 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 183h 00h R/W 8 bits The operation of this register is detailed in the description for register C0DRB0. 5.1.15 C1DRA0—Channel B DRAM Rank 0,1 Attribute MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 188h 00h R/W 8 bits The operation of this register is detailed in the description for register C0DRA0. 106 Datasheet MCHBAR Registers R 5.1.16 C1DRA2—Channel B DRAM Rank 2,3 Attribute MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 189h 00h R/W 8 bits The operation of this register is detailed in the description for register C0DRA0. 5.1.17 C1DCLKDIS—Channel B DRAM Clock Disable MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 18Ch 00h R/W 8 bits The operation of this register is detailed in the description for register C0DCLKDIS. 5.1.18 C1BNKARC—Channel B Bank Architecture MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 18Eh 0000h R/W 16 bits The operation of this register is detailed in the description for register C0BNKARC. 5.1.19 C1DRT1—Channel B DRAM Timing Register 1 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 194h 900122h R/W 32 bits The operation of this register is detailed in the description for register C0DRT1. 5.1.20 C1DRC0—Channel B DRAM Controller Mode 0 MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR 1A0h 00000000h R/W 32 bits The operation of this register is detailed in the description for register C0DRC0. Datasheet 107 MCHBAR Registers R 5.1.21 PMCFG—Power Management Configuration MMIO Range: Address Offset: Default Value: Access: Size: MCHBAR F10h 00000000h R/W 32 bits Bit Access & Default Reserved R/W 0b Description 31:5 4 Enhanced Power Management Features Enable 0 = Legacy power management mode 1 = Reserved. 3:0 Reserved 5.1.22 PMSTS—Power Management Status MMIO Range: Address Offset: Default Value: Access: Size: This register is Reset by PWROK only. Bit Access & Default Reserved R/WC/S 0b Channel B in self-refresh. This bit is set by power management hardware after Channel B is placed in self refresh as a result of a Power State or a Reset Warn sequence. It is cleared by power management hardware before starting Channel B self refresh exit sequence initiated by a power management exit. It is cleared by BIOS in a warm reset (Reset# asserted while pwrok is asserted) exit sequence. 0 = Channel B not guaranteed to be in self-refresh. 1 = Channel B in Self-Refresh. 0 R/WC/S 0b Channel A in Self-refresh. Set by power management hardware after Channel A is placed in self refresh as a result of a Power State or a Reset Warn sequence. It is cleared by power management hardware before starting Channel A self refresh exit sequence initiated by a power management exit. It is cleared by the BIOS in a warm reset (Reset# asserted while PWOK is asserted) exit sequence. 0 = Channel A not guaranteed to be in self-refresh. 1 = Channel A in Self-Refresh. Description MCHBAR F14h 00000000h R/W 32 bits 31:2 1 § 108 Datasheet EPBAR Registers—Egress Port Register Summary R 6 EPBAR Registers—Egress Port Register Summary These registers are offset from the EPBAR base address. Table 6-1. Egress Port Register Address Map Address Offset 044h–047h 050h–053h 058h– 05Fh 060h–063h 068h– 06Fh Register Symbol EPESD EPLE1D EPLE1A EPLE2D EPLE2A Register Name EP Element Self Description EP Link Entry 1 Description EP Link Entry 1 Address EP Link Entry 2 Description EP Link Entry 2 Address Default Value 0000h 0100h 000000000 0000000h 02000002h 000000000 0008000h Access R/WO, RO R/WO, RO R/WO, RO R/WO, RO RO 6.1 EP RCRB Configuration Register Details Figure 6-1. Link Declaration Topology (G)MCH X16 PEG (Port #2) Link #2 (Type 1) Link #1 (Type 0) Egress Port (Port #0) Main Memory Subsystem Link #2 (Type 0) Link #1 (Type 0) DMI (Port #1) Link #1 (Type 0) X4 Intel® ICH6 Egress Port (Port #0) Egress_LinkDeclar_Topo Datasheet 109 EPBAR Registers—Egress Port Register Summary R 6.1.1 EPESD—EP Element Self Description MMIO Range: Address Offset: Default Value: Access: Size: EPBAR 044h 00000201h R/WO, RO 32 bits This register provides information about the root complex element containing this Link Declaration capability. Bit Access & Default RO 00h R/WO 00h Description 31:24 Port Number: This field specifies the port number associated with this element with respect to the component that contains this element. A value of 00h indicates to configuration software that this is the default egress port. Component ID: This field identifies the physical component that contains this Root Complex Element. Component IDs start at 1. This value is a mirror of the value in the Component ID field of all elements in this component. The value only needs to be written in one of the mirrored fields and it will be reflected everywhere that it is mirrored. 23:16 15:8 RO 02h Number of Link Entries: This field indicates the number of link entries following the Element Self Description. This field reports 2 (one each for PCI Express* x16 interface and DMI). Reserved 7:4 3:0 RO 1h Element Type: This field Indicates the type of the Root Complex Element. 1h = Port to system memory 110 Datasheet EPBAR Registers—Egress Port Register Summary R 6.1.2 EPLE1D—EP Link Entry 1 Description MMIO Range: Address Offset: Default Value: Access: Size: EPBAR 050h 0100h R/WO, RO 32 bits This register provides the First part of a Link Entry that declares an internal link to another Root Complex Element. Bit 31:24 Access & Default RO 01h R/WO 00h Description Target Port Number: This field specifies the port number associated with the element targeted by this link entry (DMI). The target port number is with respect to the component that contains this element as specified by the target component ID. Target Component ID: This field identifies the physical or logical component that is targeted by this link entry. A value of 0 is reserved; Component IDs start at 1. This value is a mirror of the value in the Component ID field of all elements in this component. The value only needs to be written in one of the mirrored fields and it will be reflected everywhere that it is mirrored. 15:2 1 0 RO 0b R/WO 0b Reserved Link Type: This bit indicates that the link points to memory-mapped space (for RCRB). The link address specifies the 64-bit base address of the target RCRB. Link Valid 0 = Link Entry is not valid and will be ignored. 1 = Link Entry specifies a valid link. 23:16 6.1.3 EPLE1A—EP Link Entry 1 Address MMIO Range: Address Offset: Default Value: Access: Size: EPBAR 058h 0000000000000000h R/WO 64 bits This register provides the second part of a Link Entry, which declares an internal link to another Root Complex Element. Bit Access & Default Reserved R/WO 0 0000h Link Address: This field provides the memory-mapped base address of the RCRB that is the target element (DMI) for this link entry. Reserved Description 63:32 31:12 11:0 Datasheet 111 EPBAR Registers—Egress Port Register Summary R 6.1.4 EPLE2D—EP Link Entry 2 Description MMIO Range: Address Offset: Default Value: Access: Size: EPBAR 060h 02000002h R/WO, RO 32 bits This register provides the First part of a Link Entry that declares an internal link to another Root Complex Element. Bit Access & Default RO 02h Description 31:24 Target Port Number: This field specifies the port number associated with the element targeted by this link entry (PCI Express* x16 interface). The target port number is with respect to the component that contains this element as specified by the target component ID. Target Component ID: This field identifies the physical or logical component that is targeted by this link entry. A value of 0 is reserved; Component IDs start at 1. This value is a mirror of the value in the Component ID field of all elements in this component. The value only needs to be written in one of the mirrored fields and it will be reflected everywhere that it is mirrored. 23:16 R/WO 00h 15:2 1 RO 1b Reserved Link Type: 1 = Link points to configuration space of the integrated device that controls the x16 root port. The link address specifies the configuration address (segment, bus, device, function) of the target root port. Link Valid 0 = Link Entry is not valid and will be ignored. 1 = Link Entry specifies a valid link. 0 R/WO 0b 112 Datasheet EPBAR Registers—Egress Port Register Summary R 6.1.5 EPLE2A—EP Link Entry 2 Address MMIO Range: Address Offset: Default Value: Access: Size: EPBAR 068h 0000000000008000h RO 64 bits This register provides the second part of a Link Entry that declares an internal link to another Root Complex Element. Bit Access & Default Reserved RO 00h RO 0 0001b RO 000b Bus Number Device Number: Target for this link is PCI Express* x16 port (Device 1). Function Number Reserved Description 63:28 27:20 19:15 14:12 11:0 § Datasheet 113 EPBAR Registers—Egress Port Register Summary R 114 Datasheet DMIBAR Registers—Direct Media Interface (DMI) RCRB R 7 DMIBAR Registers—Direct Media Interface (DMI) RCRB This Root Complex Register Block (RCRB) controls the (G)MCH-Intel ICH6 serial interconnect. The base address of this space is programmed in DMIBAR in device 0 configuration space. These registers are offset from the DMIBAR base address Table 7-1. DMI Register Address Map Summary Address offset 000–003h 004–007h 008–00Bh 00C–00Dh 00E–00Fh 010–013h 014–017h 018–019h 01A–01Bh 01C–01Fh 020–023h 024–025h 026–027h 028–083h 084–087h 088–089h 08A–08Bh 08C–FFFh Register Symbol DMIVCECH DMIPVCCAP1 DMIPVCCAP2 DMIPVCCTL — DMIVC0RCAP DMIVC0RCTL — DMIVC0RSTS DMIVC1RCAP DMIVC1RCTL — DMIVC1RSTS — DMILCAP DMILCTL DMILSTS — Register Name DMI Virtual Channel Enhanced Capability Header DMI Port VC Capability Register 1 DMI Port VC Capability Register 2 DMI Port VC Control Reserved DMI VC0 Resource Capability DMI VC0 Resource Control Reserved DMI VC0 Resource Status DMI VC1 Resource Capability DMI VC1 Resource Control Reserved DMI VC1 Resource Status Reserved DMI Link Capabilities DMI Link Control DMI Link Status Reserved PCI Dev # DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR DMIBAR Datasheet 115 DMIBAR Registers—Direct Media Interface (DMI) RCRB R 7.1 7.1.1 Direct Media Interface (DMI) RCRB Register Details DMIVCECH—DMI Virtual Channel Enhanced Capability Header MMIO Range: Address Offset: Default Value: Access: Size: DMIBAR 000h 04010002h RO 32 bits This register indicates DMI Virtual Channel capabilities. Bit Access & Default RO 040h RO 1h RO 0002h Description 31:20 19:16 15:0 Pointer to Next Capability: This field indicates the next item in the list. Capability Version: This field indicates support as a version 1 capability structure. Capability ID: This field indicates this is the Virtual Channel capability item. 7.1.2 DMIPVCCAP1—DMI Port VC Capability Register 1 MMIO Range: Address Offset: Default Value: Access: Size: DMIBAR 004h 00000001h R/WO, RO 32 bits This register describes the configuration of Virtual Channels associated with this port. Bit Access & Default Reserved RO 00b RO 00b Port Arbitration Table Entry Size (PATS): This field indicates the size of the port arbitration table is 4 bits (to allow up to 8 ports). Reference Clock (RC) Fixed at 10 ns. Reserved RO 000b Low Priority Extended VC Count (LPEVC): This field indicates that there are no additional VCs of low priority with extended capabilities. Reserved R/WO 001b Extended VC Count: This field indicates that there is one additional VC (VC1) that exists with extended capabilities. Description 31:12 11:10 9:8 7 6:4 3 2:0 116 Datasheet DMIBAR Registers—Direct Media Interface (DMI) RCRB R 7.1.3 DMIPVCCAP2—DMI Port VC Capability Register 2 MMIO Range: Address Offset: Default Value: Access: Size: DMIBAR 008h 00000001h RO 32 bits This register describes the configuration of Virtual Channels associated with this port. Bit Access & Default RO 00h Description 31:24 23:8 7:0 VC Arbitration Table Offset (ATO): This field indicates that no table is present for VC arbitration since it is fixed. Reserved RO 01h VC Arbitration Capability: This field indicates that the VC arbitration is fixed in the root complex. VC1 is highest priority and VC0 is lowest priority. 7.1.4 DMIPVCCTL—DMI Port VC Control MMIO Range: Address Offset: Default Value: Access: Size: DMIBAR 00Ch 00000000h R/W, RO 16 bits Bit Access & Default Reserved R/W 000b RO 0b Description 15:4 3:1 VC Arbitration Select: This field indicates which VC should be programmed in the VC arbitration table. The root complex takes no action on the setting of this field since there is no arbitration table. Load VC Arbitration Table (LAT): This field indicates that the table programmed should be loaded into the VC arbitration table. This bit is defined as read/write with always returning 0 on reads. 0 Datasheet 117 DMIBAR Registers—Direct Media Interface (DMI) RCRB R 7.1.5 DMIVC0RCAP—DMI VC0 Resource Capability MMIO Range: Address Offset: Default Value: Access: Size: DMIBAR 010h 00000001h RO 32 bits Bit Access & Default RO 00h Description 31:24 23 22:16 15 14 13:8 7:0 Port Arbitration Table Offset (AT): This VC implements no port arbitration table since the arbitration is fixed. Reserved RO 00h RO 0b RO 0b Maximum Time Slots (MTS): This VC implements fixed arbitration, and therefore this field is not used. Reject Snoop Transactions (RTS): This VC must be able to take snoopable transactions. Advanced Packet Switching (APS): This VC is capable of all transactions, not just advanced packet switching transactions. Reserved RO 01h Port Arbitration Capability (PAC): This field indicates that this VC uses fixed port arbitration. 118 Datasheet DMIBAR Registers—Direct Media Interface (DMI) RCRB R 7.1.6 DMIVC0RCTL0—DMI VC0 Resource Control MMIO Range: Address Offset: Default Value: Access: Size: DMIBAR 014h 8000007Fh R/W, RO 32 bits This register controls the resources associated with PCI Express Virtual Channel 0. Bit Access & Default RO 1b Description 31 30:27 26:24 23:20 19:17 Virtual Channel Enable (EN): Enables the VC when set. Disables the VC when cleared. Reserved RO 000b Virtual Channel Identifier (ID): Indicates the ID to use for this virtual channel. Reserved R/W 0h RO 0b Port Arbitration Select (PAS): Indicates which port table is being programmed. The root complex takes no action on this setting since the arbitration is fixed and there is no arbitration table. Load Port Arbitration Table (LAT): The root complex does not implement an arbitration table for this virtual channel. Reserved 16 15:8 7:1 R/W 7Fh Transaction Class / Virtual Channel Map (TVM): This field indicates which transaction classes are mapped to this virtual channel. When a bit is set, this transaction class is mapped to the virtual channel. Reserved 0 Datasheet 119 DMIBAR Registers—Direct Media Interface (DMI) RCRB R 7.1.7 DMIVC0RSTS—DMI VC0 Resource Status MMIO Range: Address Offset: Default Value: Access: Size: DMIBAR 01Ah 00000002h RO 16 bits This register reports the Virtual Channel specific status. Bit Access & Default Reserved RO 1b VC Negotiation Pending (NP): 0 = Virtual channel is Not being negotiated with ingress ports. 1 = Virtual channel is still being negotiated with ingress ports. 0 RO 0b Port Arbitration Tables Status (ATS): There is no port arbitration table for this VC, so this bit is reserved at 0. Description 15:2 1 7.1.8 DMIVC1RCAP—DMI VC1 Resource Capability MMIO Range: Address Offset: Default Value: Access: Size: Bit Access & Default RO 00h DMIBAR 01Ch 00008001h RO 32 bits Description 31:24 Port Arbitration Table Offset (AT): This field indicates the location of the port arbitration table in the root complex. A value of 3h indicates the table is at offset 30h. Reserved 23 22:16 15 14 13:8 7:0 RO 01h RO 00h RO 1b RO 0b Maximum Time Slots (MTS): This value is updated by platform BIOS based upon the determination of the number of time slots available in the platform. Reject Snoop Transactions (RTS): All snoopable transactions on VC1 are rejected. This VC is for isochronous transfers only. Advanced Packet Switching (APS): This VC is capable of all transactions, not just advanced packet switching transactions. Reserved Port Arbitration Capability (PAC): This field indicates the port arbitration capability is time-based WRR of 128 phases. 120 Datasheet DMIBAR Registers—Direct Media Interface (DMI) RCRB R 7.1.9 DMIVC1RCTL1—DMI VC1 Resource Control MMIO Range: Address Offset: Default Value: Access: Size: DMIBAR 020h 00100000h R/W, RO 32 bits This register controls the resources associated with Virtual Channel 1. Bit Access & Default R/W 0b Virtual Channel Enable (EN): 0 = Disable. 1 = Enable. 30:27 26:24 23:20 19:17 R/W 0h RO 0h R/W 001b Reserved Virtual Channel Identifier (ID): This field indicates the ID to use for this virtual channel. Reserved Port Arbitration Select (PAS): This field indicates which port table is being programmed. The only permissible value of this field is 4h for the time-based WRR entries. Reserved R/W 00h Transaction Class / Virtual Channel Map (TVM): This field indicates which transaction classes are mapped to this virtual channel. When a bit is set, this transaction class is mapped to the virtual channel. Reserved Description 31 16:8 7:1 0 7.1.10 DMIVC1RSTS—DMI VC1 Resource Status MMIO Range: Address Offset: Default Value: Access: Size: DMIBAR 026h 0000h RO 16 bits This register reports the Virtual Channel specific status. Bit Access & Default Reserved RO 0b VC Negotiation Pending (NP): 0 = Virtual channel is Not being negotiated with ingress ports. 1 = Virtual channel is still being negotiated with ingress ports. 0 Reserved Description 15:2 1 Datasheet 121 DMIBAR Registers—Direct Media Interface (DMI) RCRB R 7.1.11 DMILCAP—DMI Link Capabilities MMIO Range: Address Offset: Default Value: Access: Size: DMIBAR 084h 00012C41h R/WO, RO 32 bits This register indicates DMI specific capabilities. Bit Access & Default Reserved R/WO 010b R/WO 010b RO 11b RO 4h RO 1h L1 Exit Latency (EL1). L1 not supported on DMI. L0s Exit Latency (EL0): This field indicates that exit latency is 128 ns to less than 256 ns. Active State Link PM Support (APMS): This field indicates that L0s is supported on DMI. Maximum Link Width (MLW): This field indicates the maximum link width is 4 ports. Maximum Link Speed (MLS): This field indicates the link speed is 2.5 Gb/s. Description 31:18 17:15 14:12 11:10 9:4 3:0 7.1.12 DMILCTL—DMI Link Control MMIO Range: Address Offset: Default Value: Access: Size: This register allows control of DMI. Bit Access & Default Reserved R/W 0h Extended Synch (ES): 1 = Forces extended transmission of FTS ordered sets when exiting L0s prior to entering L0 and extra TS1 sequences at exit from L1 prior to entering L0. Reserved R/W 00b Active State Link PM Control (APMC): Indicates whether DMI should enter L0s. 00 = Disabled 01 = L0s entry enabled 10 = Reserved 11 = Reserved Description DMIBAR 088h 0000h R/W 16 bits 15:8 7 6:2 1:0 122 Datasheet DMIBAR Registers—Direct Media Interface (DMI) RCRB R 7.1.13 DMILSTS—DMI Link Status MMIO Range: Address Offset: Default Value: Access: Size: This register indicates DMI status. Bit Access & Default Reserved RO 00h Negotiated Link Width (NLW): This field is valid only when the link is in the L0, L0s, or L1 states (after link width negotiation is successfully completed). Negotiated link width is x4 (000100b). All other encodings are reserved. 3:0 RO 1h Link Speed (LS) Link is 2.5 Gb/s. Description DMIBAR 08Ah 0001h RO 16 bits 15:10 9:4 § Datasheet 123 DMIBAR Registers—Direct Media Interface (DMI) RCRB R 124 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) Device 1contains the controls associated with the PCI Express x16 root port that is the intended to attach as the point for external graphics. It is typically referred to as PCI Express* x16 Graphics Interface port. In addition, it also functions as the virtual PCI-to-PCI bridge. Warning: When reading the PCI Express "conceptual" registers such as this, you may not get a valid value unless the register value is stable. The PCI Express* Specification defines two types of reserved bits: Reserved and Preserved: • Reserved for future R/W implementations; software must preserve value read for writes to bits. • Reserved and Zero: Reserved for future R/WC/S implementations; software must use 0 for writes to bits. Unless explicitly documented as Reserved and Zero, all bits marked as reserved are part of the Reserved and Preserved type that have historically been the typical definition for Reserved. It is important to note that most (if not all) control bits in this device cannot be modified unless the link is down. Software is required to first Disable the link, then program the registers, and then re-enable the link (which will cause a full-retrain with the new settings). Table 8-1. Host-PCI Express* Graphics Bridge Register Address Map (D1:F0) Address Offset 00–01h 02–03h 04–05h 06–07h 08h Register Symbol VID1 DID1 PCICMD1 PCISTS1 RID1 Register Name Vendor Identification Device Identification PCI Command PCI Status Revision Identification Default Value 8086h 2581h 0000h 0000h See register description 060400h 00h — 01h Access RO RO RO, R/W RO, R/W RO 09–0Bh 0Ch 0Dh 0Eh CC1 CL1 — HDR1 Class Code Cache Line Size Reserved Header Type RO R/W — RO Datasheet 125 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R Address Offset 0F–17h 18h 19h 1Ah 1Bh 1Ch 1Dh 1Eh–1Fh 20–21h 22–23h 24–25h 26–27h 28–33h 34h 35–3Bh 3Ch 3Dh 3E–3Fh 40–7Fh 80–83h Register Symbol — PBUSN1 SBUSN1 SUBUSN1 — IOBASE1 IOLIMIT1 SSTS1 MBASE1 MLIMIT1 PMBASE1 PMLIMIT1 — CAPPTR1 — INTRLINE1 INTRPIN1 BCTRL1 — PM_CAPID1 Reserved Register Name Default Value — 00h 00h 00h — F0h 00h 00h FFF0h 0000h FFF0h 0000h — 88h — 00h 00h 0000h — 19029001h or 1902A001h 00000000h 0000800D h 00008086h A005h 0000h 00000000h 0000h — 0010h 0141h 00000000h 0000h 0000h 02012E01h 0000h Access — RO RO R/W — RO R/W RO, R/W/C R/W R/W RO, R/W RO, R/W — RO — R/W RO RO, R/W — RO Primary Bus Number Secondary Bus Number Subordinate Bus Number Reserved I/O Base Address I/O Limit Address Secondary Status Memory Base Address Memory Limit Address Prefetchable Memory Base Address Prefetchable Memory Limit Address Reserved Capabilities Pointer Reserved Interrupt Line Interrupt Pin Bridge Control Reserved Power Management Capabilities 84–87h 88–8Bh 8C–8Fh 90–91h 92–93h 94–97h 98–99h 9A–9Fh A0–A1h A2–A3h A4–A7h A8–A9h AA–ABh AC–AFh B0–B1h PM_CS1 SS_CAPID SS MSI_CAPID MC MA MD — PEG_CAPL PEG_CAP DCAP DCTL DSTS LCAP LCTL Power Management Control/Status Subsystem ID and Vendor ID Capabilities Subsystem ID and Subsystem Vendor ID Message Signaled Interrupts Capability ID Message Control Message Address Message Data Reserved PCI Express* Capability List PCI Express Capabilities Device Capabilities Device Control Device Status Link Capabilities Link Control RO, R/W/S RO RO RO RO, R/W RO, R/W R/W — RO RO RO R/W RO R/WO RO, R/W 126 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R Address Offset B2–B3h B4–B7h B8–B9h BA–BBh BC–BDh BE–BFh C0–C3h C4–EBh EC–EFh F0–FFh 100–103h 104–107h 108–10Bh 10C–10Dh 10E–10Fh 110–113h 114–117h 118–119h 11A–11Bh 11C–11Fh 120–123h 124–125h 126–127h 128–13Fh 140–143h 144–147h 148–14Fh 150–153h 154–157h 158–15Fh 160–217h 218–21Fh 220–FFFh Register Symbol LSTS SLOTCAP SLOTCTL SLOTSTS RCTL — RSTS — PEGLC — VCECH PVCCAP1 PVCCAP2 PVCCTL — VC0RCAP VC0RCTL — VC0RSTS VC1RCAP VC1RCTL — VC1RSTS — RCLDECH ESD — LE1D — LE1A — PEGSSTS — Link Status Register Name Default Value 1001h 00000000h 01C0h 0X00h 0000h — 00000000h — 00000000h — 14010002h 00000001h 00000001h 0000h — 00000000h 8000007Fh — 0000h 00008000h 01000000h — 0000h — 00010005h 02000100h — 00000000h — 000000000 0000000h — 000000000 0000FFFh — Access RO R/WO R/W RO, R/W/C R/W — RO, R/W/C — R/W, RO — RO RO, R/WO RO R/W — RO RO, R/W — RO RO RO, R/W — RO — RO RO, R/WO — RO, R/WO — R/WO — RO — Slot Capabilities Slot Control Slot Status Root Control Reserved Root Status Reserved PCI Express*-Graphics Legacy Control Reserved Virtual Channel Enhanced Capability Header Port VC Capability Register 1 Port VC Capability Register 2 Port VC Control Reserved VC0 Resource Capability VC0 Resource Control Reserved VC0 Resource Status VC1 Resource Capability VC1 Resource Control Reserved VC1 Resource Status Reserved Root Complex Link Declaration Enhanced Capability Header Element Self Description Reserved Link Entry 1 Description Reserved Link Entry 1 Address Reserved PCI Express*-Graphics Sequence Status Reserved Datasheet 127 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1 8.1.1 Host-PCI Express* Bridge PCI Register Details (D1:F0) VID1—Vendor Identification (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 00h 8086h RO 16 bits This register combined with the Device Identification register uniquely identifies any PCI device. Bit Access & Default RO 8086h Description 15:0 Vendor Identification (VID1): PCI standard identification for Intel. 8.1.2 DID1—Device Identification (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 02h 2581h RO 16 bits This register combined with the Vendor Identification register uniquely identifies any PCI device. Bit Access & Default RO 2581h Description 15:0 Device Identification Number (DID1): This field is an identifier assigned to the (G)MCH device 1 (virtual PCI-to-PCI bridge, PCI Express* Graphics port). 128 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.3 PCICMD1—PCI Command (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: Bit Access & Default Reserved R/W 0b INTA Assertion Disable: 0 = This device is permitted to generate INTA interrupt messages. 1 = This device is prevented from generating interrupt messages. Any INTA emulation interrupts already asserted must be de-asserted when this bit is set. Only affects interrupts generated by the device (PCI INTA from a PME or Hot Plug event) controlled by this command register. It does not affect upstream MSIs, upstream PCI INTA-INTD asserts and de-assert messages. 9 8 RO 0b R/W 0b Fast Back-to-Back Enable (FB2B): Not Applicable or Implemented. Hardwired to 0. SERR Message Enable (SERRE1): This bit is an enable bit for Device 1 SERR messaging. The (G)MCH communicates the SERR# condition by sending a ® SERR message to the Intel ICH6. This bit, when set, enables reporting of nonfatal and fatal errors to the Root Complex. Note that errors are reported if enabled either through this bit or through the PCI Express* specific bits in the Device Control Register 0 = The SERR message is generated by the (G)MCH for Device 1 only under conditions enabled individually through the Device Control Register. 1 = The (G)MCH is enabled to generate SERR messages which will be sent to the ICH6 for specific Device 1 error conditions that are individually enabled in the BCTRL1 register and for all non-fatal and fatal errors generated on the primary side of the virtual PCI to PCI Express bridge (not those received by the secondary side). The error status is reported in the PCISTS1 register. 7 6 R/WO 0b Reserved Parity Error Enable (PERRE): This bit controls whether or not the Master Data Parity Error bit in the PCI Status register can bet set. 0 = Master Data Parity Error bit in PCI Status register cannot be set. 1 = Master Data Parity Error bit in PCI Status register can be set. 5 4 3 RO 0b RO 0b RO 0b VGA Palette Snoop: Hardwired to 0. Memory Write and Invalidate Enable (MWIE): Hardwired to 0. Special Cycle Enable (SCE): Hardwired to 0. 1 04h 0000h RO, R/W 16 bits Description 15:11 10 Datasheet 129 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R Bit Access & Default R/W 0b Description 2 Bus Master Enable (BME): This bit does not affect forwarding of completions from the primary interface to the secondary interface. 0 = This device is prevented from making memory or I/O requests to its primary bus. Note that according to the PCI specification, as MSI interrupt messages are in-band memory writes, disabling the bus master enable bit prevents this device from generating MSI interrupt messages or passing them from its secondary bus to its primary bus. Upstream memory writes/reads, I/O writes/reads, peer writes/reads, and MSIs will all be treated as illegal cycles. Writes are forwarded to memory address 0h with byte enables de-asserted. Reads will be forwarded to memory address 0h and will return Unsupported Request status (or Master abort) in its completion packet. 1 = This device is allowed to issue requests to its primary bus. Completions for previously issued memory read requests on the primary bus will be issued when the data is available. 1 R/W 0b Memory Access Enable (MAE) 0 = All of device 1’s memory space is disabled. 1 = Enable the Memory and Pre-fetchable memory address ranges defined in the MBASE1, MLIMIT1, PMBASE1, and PMLIMIT1 registers. 0 R/W 0b IO Access Enable (IOAE) 0 = All of device 1’s I/O space is disabled. 1 = Enable the I/O address range defined in the IOBASE1 and IOLIMIT1 registers. 8.1.4 PCISTS1—PCI Status (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 06h 0000h RO, R/W/C 16 bits This register reports the occurrence of error conditions associated with primary side of the “virtual” Host-PCI Express bridge in the (G)MCH. Bit Access & Default RO 0b R/WC 0b Description 15 14 Detected Parity Error (DPE): Hardwired to 0. Parity (generating poisoned TLPs) is not supported on the primary side of this device. Signaled System Error (SSE): 1 = This bit is set when this Device sends an SERR due to detecting an ERR_FATAL or ERR_NONFATAL condition and the SERR Enable bit in the Command register is ‘1’. Both received (if enabled by BCTRL1[1]) and internally detected error messages do not affect this field. Received Master Abort Status (RMAS): Not Applicable or Implemented. Hardwired to 0. The concept of a master abort does not exist on primary side of this device. 13 RO 0b 130 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R Bit Access & Default RO 0b RO 0b RO 00b RO 0b Description 12 11 10:9 Received Target Abort Status (RTAS): Hardwired to 0. The concept of a target abort does not exist on primary side of this device. Signaled Target Abort Status (STAS): Hardwired to 0. The concept of a target abort does not exist on primary side of this device. DEVSELB Timing (DEVT): This device is not the subtractive decoded device on bus 0. This bit field is therefore hardwired to 00b to indicate that the device uses the fastest possible decode. Master Data Parity Error (PMDPE): Because the primary side of the PCI Express* x16 Graphics Interface’s virtual PCI-to-PCI bridge is integrated with the (G)MCH functionality, there is no scenario where this bit will get set. Because hardware will never set this bit, it is impossible for software to have an opportunity to clear this bit or otherwise test that it is implemented. The PCI specification defines it as a R/WC; however, for this implementation, an RO definition behaves the same way and will meet all Microsoft testing requirements. This bit can only be set when the Parity Error Enable bit in the PCI Command register is set. 8 7 6 5 4 3 RO 0b Fast Back-to-Back (FB2B): Hardwired to 0. Reserved RO 0b RO 1b RO 0b 66/60MHz capability (CAP66): Hardwired to 0. Capabilities List: This bit indicates that a capabilities list is present. Hardwired to 1. INTA Status: This field indicates that an interrupt message is pending internally to the device. Only PME and Hot Plug sources feed into this status bit (not PCI INTA-INTD assert and de-assert messages). The INTA Assertion Disable bit, PCICMD1[10], has no effect on this bit. Reserved 2:0 Datasheet 131 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.5 RID1—Revision Identification (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 08h See bit description RO 8 bits This register contains the revision number of the (G)MCH device 1. Bit Access & Default RO 00h Description 7:0 Revision Identification Number (RID1): This field indicates the number of times that this device in this component has been “stepped” through the manufacturing ® process. Refer to the Intel 82915G/82915P/82915PL/82915GV/82915GL/82910GL Express Chipset Specification Update for the value of the Revision ID Register. 8.1.6 CC1—Class Code (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 09h 060400h RO 24 bits This register identifies the basic function of the device, a more specific sub-class, and a registerspecific programming interface. Bit Access & Default RO 06h Description 23:16 Base Class Code (BCC): This field indicates the base class code for this device. 06h = Bridge device. 15:8 RO 04h Sub-Class Code (SUBCC): This field indicates the sub-class code for this device. 04h = PCI-to-PCI Bridge. 7:0 RO 00h Programming Interface (PI): This field indicates the programming interface of this device. This value does not specify a particular register set layout and provides no practical use for this device. 132 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.7 CL1—Cache Line Size (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 0Ch 00h R/W 8 bits Bit Access & Default R/W 00h Description 7:0 Cache Line Size (Scratch pad): This field is implemented by PCI Express* devices as a read/write field for legacy compatibility purposes but has no impact on any PCI Express device functionality. 8.1.8 HDR1—Header Type (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 0Eh 01h RO 8 bits This register identifies the header layout of the configuration space. No physical register exists at this location. Bit Access & Default RO 01h Description 7:0 Header Type Register (HDR): This field returns 01h to indicate that this is a single function device with bridge header layout. 8.1.9 PBUSN1—Primary Bus Number (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 18h 00h RO 8 bits This register identifies that this “virtual” Host-PCI Express bridge is connected to PCI bus 0. Bit Access & Default RO 00h Description 7:0 Primary Bus Number (BUSN): Configuration software typically programs this field with the number of the bus on the primary side of the bridge. Since device 1 is an internal device and its primary bus is always 0, these bits are read only and are hardwired to 0. Datasheet 133 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.10 SBUSN1—Secondary Bus Number (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 19h 00h RO 8 bits This register identifies the bus number assigned to the second bus side of the “virtual” bridge i.e. to PCI Express Graphics. This number is programmed by the PCI configuration software to allow mapping of configuration cycles to PCI Express Graphics. Bit Access & Default R/W 00h Description 7:0 Secondary Bus Number (BUSN): This field is programmed by configuration software with the bus number assigned to PCI Express*-G. 8.1.11 SUBUSN1—Subordinate Bus Number (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 1Ah 00h R/W 8 bits This register identifies the subordinate bus (if any) that resides at the level below PCI Express Graphics. This number is programmed by the PCI configuration software to allow mapping of configuration cycles to PCI Express Graphics. Bit Access & Default R/W 00h Description 7:0 Subordinate Bus Number (BUSN): This register is programmed by configuration software with the number of the highest subordinate bus that lies behind the device 1 bridge. When only a single PCI device resides on the PCI Express*-G segment, this register will contain the same value as the SBUSN1 register. 134 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.12 IOBASE1—I/O Base Address (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 1Ch F0h RO 8 bits This register controls the processor-to-PCI Express Graphics I/O access routing based on the following formula: IO_BASE ≤ address ≤ IO_LIMIT Only the upper 4 bits are programmable. For the purpose of address decode, address bits A[11:0] are treated as 0. Thus, the bottom of the defined I/O address range will be aligned to a 4-KB boundary. Bit Access & Default R/W Fh Description 7:4 I/O Address Base (IOBASE): This field corresponds to A[15:12] of the I/O addresses passed by bridge 1 to PCI Express*-G. BIOS must not set this register to 00h; otherwise, 0CF8h/0CFCh accesses will be forwarded to the PCI Express hierarchy associated with this device. Reserved 3:0 8.1.13 IOLIMIT1—I/O Limit Address (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 1Dh 00h R/W 8 bits This register controls the processor-to-PCI Express Graphics I/O access routing based on the following formula: IO_BASE ≤ address ≤ IO_LIMIT Only the upper 4 bits are programmable. For the purposes of address decode, address bits A[11:0] are assumed to be FFFh. Thus, the top of the defined I/O address range will be at the top of a 4KB aligned address block. Bit Access & Default R/W 0h Description 7:4 I/O Address Limit (IOLIMIT): This field corresponds to A[15:12] of the I/O address limit of device 1. Devices between this upper limit and IOBASE1 will be passed to the PCI Express* hierarchy associated with this device. Reserved 3:0 Datasheet 135 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.14 SSTS1—Secondary Status (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 1Eh 00h RO, R/W/C 16 bits SSTS1 is a 16-bit status register that reports the occurrence of error conditions associated with secondary side (i.e., PCI Express Graphics side) of the “virtual” PCI-PCI Bridge in the (G)MCH. Bit Access & Default R/WC 0b Detected Parity Error (DPE): 1 = The MCH received across the link (upstream) a Posted Write Data Poisoned TLP (EP=1). Received System Error (RSE): 1 = Secondary side sends an ERR_FATAL or ERR_NONFATAL message due to an error detected by the secondary side, and the SERR Enable bit in the Bridge Control register is 1. Received Master Abort (RMA): 1 = Secondary Side for Type 1 Configuration Space Header Device (for requests initiated by the Type 1 Header Device itself) receives a completion with Unsupported Request Completion Status. Received Target Abort (RTA): 1 = Secondary Side for Type 1 Configuration Space Header Device (for requests initiated by the Type 1 Header Device itself) receives a completion with Completer Abort Completion Status. Signaled Target Abort (STA): Hardwired to 0. The (G)MCH does not generate Target Aborts (the (G)MCH will never complete a request using the Completer Abort Completion status). DEVSELB Timing (DEVT): Hardwired to 0. Master Data Parity Error (SMDPE). 1 = The MCH received across the link (upstream) a Read Data Completion Poisoned TLP (EP=1). Note: This bit can only be set when the Parity Error Enable bit in the Bridge Control register is set. 7 6 5 4:0 RO 0b RO 0b Fast Back-to-Back (FB2B): Hardwired to 0. Reserved 66/60 MHz capability (CAP66): Hardwired to 0. Reserved Description 15 14 R/WC 0b 13 R/WC 0b 12 R/WC 0b 11 RO 0b RO 00b R/WC 0b 10:9 8 136 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.15 MBASE1—Memory Base Address (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 20h FFF0h R/W 16 bits This register controls the processor to PCI Express Graphics non-prefetchable memory access routing based on the following formula: MEMORY_BASE ≤ address ≤ MEMORY_LIMIT The upper 12 bits of the register are read/write and correspond to the upper 12 address bits A[31:20] of the 32-bit address. The bottom 4 bits of this register are read-only and return zeroes when read. The configuration software must initialize this register. For the purpose of address decode, address bits A[19:0] are assumed to be 0. Thus, the bottom of the defined memory address range will be aligned to a 1-MB boundary. Bit Access & Default R/W FFFh Description 15:4 3:0 Memory Address Base (MBASE): This field corresponds to A[31:20] of the lower limit of the memory range that will be passed to PCI Express*. Reserved Datasheet 137 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.16 MLIMIT1—Memory Limit Address (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 22h 0000h R/W 16 bits This register controls the processor-to-PCI Express Graphics non-prefetchable memory access routing based on the following formula: MEMORY_BASE ≤ address ≤ MEMORY_LIMIT The upper 12 bits of the register are read/write and correspond to the upper 12 address bits A[31:20] of the 32-bit address. The bottom 4 bits of this register are read-only and return zeroes when read. Configuration software must initialize this register. For the purpose of address decode, address bits A[19:0] are assumed to be FFFFFh. Thus, the top of the defined memory address range will be at the top of a 1-MB aligned memory block. Note: Memory range covered by MBASE and MLIMIT registers are used to map non-prefetchable PCI Express Graphics address ranges (typically, where control/status memory-mapped I/O data structures of the graphics controller will reside) and PMBASE and PMLIMIT are used to map prefetchable address ranges (typically, graphics local memory). This segregation allows application of USWC space attribute to be performed in a true plug-and-play manner to the prefetchable address range for improved processor-PCI Express memory access performance. Note: Configuration software is responsible for programming all address range registers (prefetchable, non-prefetchable) with the values that provide exclusive address ranges (i.e., prevent overlap with each other and/or with the ranges covered with the main memory). There is no provision in the (G)MCH hardware to enforce prevention of overlap and operations of the system in the case of overlap are not guaranteed. Bit Access & Default R/W 000h Description 15:4 3:0 Memory Address Limit (MLIMIT): This field corresponds to A[31:20] of the upper limit of the address range passed to PCI Express*. Reserved 138 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.17 PMBASE1—Prefetchable Memory Base Address (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 24h FFF0h RO, R/W 16 bits This register, in conjunction with the corresponding Upper Base Address register, controls the processor-to-PCI Express Graphics prefetchable memory access routing based on the following formula: PREFETCHABLE_MEMORY_BASE ≤ address ≤ PREFETCHABLE_MEMORY_LIMIT The upper 12 bits of this register are read/write and correspond to address bits A[31:20] of the 40bit address. The lower 8 bits of the Upper Base Address register are read/write and correspond to address bits A[39:32] of the 40-bit address. The configuration software must initialize this register. For the purpose of address decode, address bits A[19:0] are assumed to be 0. Thus, the bottom of the defined memory address range will be aligned to a 1-MB boundary. Bit Access & Default R/W FFFh RO 0h Description 15:4 Prefetchable Memory Base Address (MBASE): This field corresponds to A[31:20] of the lower limit of the memory range that will be passed to PCI Express*. 64-bit Address Support: This field indicates that the bridge supports only 32 bit addresses. 3:0 Datasheet 139 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.18 PMLIMIT1—Prefetchable Memory Limit Address (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 26h 0000h RO, R/W 16 bits This register, in conjunction with the corresponding Upper Limit Address register, controls the processor-to-PCI Express Graphics prefetchable memory access routing based on the following formula: PREFETCHABLE_MEMORY_BASE ≤ address ≤ PREFETCHABLE_MEMORY_LIMIT The upper 12 bits of this register are read/write and correspond to address bits A[31:20] of the 40bit address. The lower 8 bits of the Upper Limit Address register are read/write and correspond to address bits A[39:32] of the 40-bit address. The configuration software must initialize this register. For the purpose of address decode, address bits A[19:0] are assumed to be FFFFFh. Thus, the top of the defined memory address range will be at the top of a 1-MB aligned memory block. Note that prefetchable memory range is supported to allow segregation by the configuration software between the memory ranges that must be defined as UC and the ones that can be designated as a USWC (i.e., prefetchable) from the processor perspective. Bit Access & Default R/W 000h RO 0h Description 15:4 3:0 Prefetchable Memory Address Limit (PMLIMIT): This field corresponds to A[31:20] of the upper limit of the address range passed to PCI Express*. 64-bit Address Support: This field indicates the bridge supports only 32 bit addresses. 8.1.19 CAPPTR1—Capabilities Pointer (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 34h 88h RO 8 bits The capabilities pointer provides the address offset to the location of the first entry in this device’s linked list of capabilities. Bit Access & Default RO 88h Description 7:0 First Capability (CAPPTR1): The first capability in the list is the Subsystem ID and Subsystem Vendor ID Capability. 140 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.20 INTRLINE1—Interrupt Line (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 3Ch 00h R/W 8 bits This register contains interrupt line routing information. The device itself does not use this value; rather device drivers and operating systems use it to determine priority and vector information. Bit Access & Default R/W 00h Description 7:0 Interrupt Connection: This field is 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 this device’s interrupt pin is connected to. 8.1.21 INTRPIN1—Interrupt Pin (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 3Dh 00h RO 8 bits This register specifies which interrupt pin this device uses. Bit Access & Default RO 01h Description 7:0 Interrupt Pin: As a single function device, the PCI Express* device specifies INTA as its interrupt pin. 01h = INTA Datasheet 141 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.22 BCTRL1—Bridge Control (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 3Eh 0000h RO, R/W 16 bits This register provides extensions to the PCICMD1 register that are specific to PCI-PCI bridges. The BCTRL provides additional control for the secondary interface (i.e., PCI Express) as well as some bits that affect the overall behavior of the “virtual” Host-PCI Express bridge embedded within (G)MCH (e.g., VGA compatible address ranges mapping). Bit Access & Default Reserved RO 0b RO 0b RO 0b RO 0b RO 0b R/W 0b RO 0b R/W 0b Discard Timer SERR Enable: Hardwired to 0. Discard Timer Status: Hardwired to 0. Secondary Discard Timer: Hardwired to 0. Primary Discard Timer: Hardwired to 0. Fast Back-to-Back Enable (FB2BEN): Hardwired to 0. Secondary Bus Reset (SRESET): Setting this bit triggers a hot reset on the corresponding PCI Express* Port. Master Abort Mode (MAMODE): When acting as a master, unclaimed reads that experience a master abort returns all 1s and any writes that experience a master abort completes normally and the data is thrown away. Hardwired to 0. VGA 16-bit Decode: This bit enables the PCI-to-PCI bridge to provide 16-bit decoding of VGA I/O address precluding the decoding of alias addresses every 1 KB. This bit only has meaning if bit 3 (VGA Enable) of this register is also set to 1, enabling VGA I/O decoding and forwarding by the bridge. 0 = Execute 10-bit address decodes on VGA I/O accesses. 1 = Execute 16-bit address decodes on VGA I/O accesses. 3 R/W 0b VGA Enable (VGAEN): This bit controls the routing of processor-initiated transactions targeting VGA compatible I/O and memory address ranges. See the VGAEN/MDAP table in Device 0, offset 97h[0]. Description 15:12 11 10 9 8 7 6 5 4 142 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R Bit Access & Default R/W 0b Description 2 ISA Enable (ISAEN): This bit is needed to exclude legacy resource decode to route ISA resources to legacy decode path. This bit modifies the response by the (G)MCH to an I/O access issued by the processor that target ISA I/O addresses. This applies only to I/O addresses that are enabled by the IOBASE and IOLIMIT registers. 0 = All addresses defined by the IOBASE and IOLIMIT for processor I/O transactions will be mapped to PCI Express Graphics. 1 = (G)MCH will not forward to PCI Express Graphics any I/O transactions addressing the last 768 bytes in each 1-KB block, even if the addresses are within the range defined by the IOBASE and IOLIMIT registers. Instead of going to PCI Express Graphics, these cycles are forwarded to DMI where they can be subtractively or positively claimed by the ISA bridge. 1 R/W 0b SERR Enable (SERREN) 0 = No forwarding of error messages from secondary side to primary side that could result in an SERR. 1 = ERR_COR, ERR_NONFATAL, and ERR_FATAL messages result in SERR message when individually enabled by the Root Control register. 0 RO 0b Parity Error Response Enable (PEREN): This bit controls whether or not the Master Data Parity Error bit in the Secondary Status register is set when the MCH receives across the link (upstream) a Read Data Completion Poisoned TLP. 0 = Master Data Parity Error bit in Secondary Status register cannot be set. 1 = Master Data Parity Error bit in Secondary Status register can be set.. Datasheet 143 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.23 PM_CAPID1—Power Management Capabilities (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 80h 1902 9001h or 1902 A001h RO 32 bits Bit Access & Default RO 19h Description 31:27 PME Support: This field indicates the power states in which this device may indicate PME wake via PCI Express messaging. D0, D3hot, and D3cold. This device is not required to do anything to support D3hot and D3cold; it simply must report that those states are supported. Refer to the PCI Power Management 1.1 specification for encoding explanation and other power management details. D2: Hardwired to 0 to indicate that the D2 power management state is NOT supported. D1: Hardwired to 0 to indicate that the D1 power management state is NOT supported. Auxiliary Current: Hardwired to 0 to indicate that there are no 3.3Vaux auxiliary current requirements. Device Specific Initialization (DSI): Hardwired to 0 to indicate that special initialization of this device is NOT required before generic class device driver is to use it. Auxiliary Power Source (APS): Hardwired to 0. PME Clock: Hardwired to 0 to indicate this device does NOT support PME# generation. PCI PM CAP Version: Hardwired to 02h to indicate there are 4 bytes of power management registers implemented and that this device complies with revision 1.1 of the PCI Power Management Interface Specification. Pointer to Next Capability: This field contains a pointer to the next item in the capabilities list. If MSICH (CAPL[0] @ 7Fh) is 0, then the next item in the capabilities list is the Message Signaled Interrupts (MSI) capability at 90h. If MSICH (CAPL[0] @ 7Fh) is 1, then the next item in the capabilities list is the PCI Express* capability at A0h. Capability ID: Value of 01h identifies this linked list item (capability structure) as being for PCI Power Management registers. 26 25 24:22 21 RO 0b RO 0b RO 000b RO 0b RO 0b RO 0b RO 010b RO 90h or A0h RO 01h 20 19 18:16 15:8 7:0 144 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.24 PM_CS1—Power Management Control/Status (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 84h 00000000h RO, R/W/S 32 bits Bit Access & Default Reserved RO 0b RO 00b RO 0h R/W/S 0b Description 31:16 15 14:13 12:9 8 PME Status: This bit indicates that this device does not support PME# generation from D3cold. Data Scale: This field indicates that this device does not support the power management data register. Data Select: This field indicates that this device does not support the power management data register. PME Enable: This bit indicates that this device does not generate PMEB assertion from any D-state. 0 = PMEB generation not possible from any D State 1 = PMEB generation enabled from any D State The setting of this bit has no effect on hardware. See PM_CAP[15:11] 7:2 1:0 R/W 00b Reserved Power State: This field indicates the current power state of this device and can be used to set the device 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 = D1 (Not supported in this device.) 10 = D2 (Not supported in this device.) 11 = D3 Support of D3cold does not require any special action. While in the D3hot state, this device can only act as the target of PCI configuration transactions (for power management control). This device also cannot generate interrupts or respond to MMR cycles in the D3 state. The device must return to the D0 state to be fully functional. There is no hardware functionality required to support these power states. Datasheet 145 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.25 SS_CAPID—Subsystem ID and Vendor ID Capabilities (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 88h 0000800Dh RO 32 bits This capability is used to uniquely identify the subsystem where the PCI device resides. Because this device is an integrated part of the system and not an add-in device, it is anticipated that this capability will never be used. However, it is necessary because Microsoft will test for its presence. Bit Access & Default Reserved RO 80h RO 0D h Description 31:16 15:8 7:0 Pointer to Next Capability: This field contains a pointer to the next item in the capabilities list which is the PCI Power Management capability. Capability ID: A value of 0Dh identifies this linked list item (capability structure) as being for SSID/SSVID registers in a PCI-to-PCI Bridge. 8.1.26 SS—Subsystem ID and Subsystem Vendor ID (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 8Ch 00008086h RO 32 bits System BIOS can be used as the mechanism for loading the SSID/SVID values. These values must be preserved through power management transitions and hardware reset. Bit Access & Default R/WO 0000h R/WO 8086h Description 31:16 15:0 Subsystem ID (SSID): This field identifies the particular subsystem and is assigned by the vendor. Subsystem Vendor ID (SSVID): This field identifies the manufacturer of the subsystem and is the same as the vendor ID that is assigned by the PCI Special Interest Group. 146 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.27 MSI_CAPID—Message Signaled Interrupts Capability ID (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 90h A005h RO 16 bits When a device supports MSI, it can generate an interrupt request to the processor by writing a predefined data item (a message) to a predefined memory address. The reporting of the existence of this capability can be disabled by setting MSICH (CAPL [0] at 7Fh). In that case walking this linked list will skip this capability and, instead, go directly from the PCI PM capability to the PCI Express capability. Bit Access & Default RO A0h RO 05h Description 15:8 7:0 Pointer to Next Capability: This field contains a pointer to the next item in the capabilities list that is the PCI Express* capability. Capability ID: 05h = Identifies this linked list item (capability structure) as being for MSI registers. Datasheet 147 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.28 MC—Message Control (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 92h 0000h RO, R/W 16 bits System software can modify bits in this register, but the device is prohibited from doing so. If the device writes the same message multiple times, only one of those messages is guaranteed to be serviced. If all of them must be serviced, the device must not generate the same message again until the driver services the earlier one. Bit Access & Default Reserved RO 0b R/W 000b Description 15:8 7 64-bit Address Capable: Hardwired to 0 to indicate that the function does not implement the upper 32 bits of the Message Address register and is incapable of generating a 64-bit memory address. Multiple Message Enable (MME): System software programs this field to indicate the actual number of messages allocated to this device. This number will be equal to or less than the number actually requested. 000 = 1 message allocated 001–111 = Reserved 6:4 3:1 RO 000b Multiple Message Capable (MMC): System software reads this field to determine the number of messages being requested by this device. 000 = 1 message requested 001–111 = Reserved 0 R/W 0b MSI Enable (MSIEN) Controls the ability of this device to generate MSIs. 0 = MSI will not be generated. 1 = MSI will be generated when we receive PME or HotPlug messages. INTA will not be generated and INTA Status (PCISTS1[3]) will not be set. 148 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.29 MA—Message Address (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 94h 00000000h RO, R/W 32 bits Bit Access & Default R/W 00000000 h Description 31:2 Message Address: This field is used by system software to assign an MSI address to the device. The device handles an MSI by writing the padded contents of the MD register to this address. 1:0 RO 00b Force DWord Align: Hardwired to 0 so that addresses assigned by system software are always aligned on a DWord address boundary. 8.1.30 MD—Message Data (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 98h 0000h R/W 16 bits Bit Access & Default R/W 0000h Description 15:0 Message Data: This field provides a base message data pattern assigned by system software and used to handle an MSI from the device. When the device must generate an interrupt request, it writes a 32-bit value to the memory address specified in the MA register. The upper 16 bits are always set to 0. This register supplies the lower 16 bits. Datasheet 149 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.31 PEG_CAPL—PCI Express* Capability List (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 A0h 0010h RO 16 bits This register enumerates the PCI Express capability structure. Bit Access & Default RO 00h Description 15:8 Pointer to Next Capability: This value terminates the capabilities list. The Virtual Channel capability and any other PCI Express* specific capabilities that are reported via this mechanism are in a separate capabilities list located entirely within PCI Express extended configuration space. Capability ID: This field identifies this linked list item (capability structure) as being for PCI Express registers. 7:0 RO 10h 8.1.32 PEG_CAP—PCI Express*-G Capabilities (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 A2h 0141h RO 16 bits Indicates PCI Express device capabilities. Bit Access & Default Reserved RO 00h R/WO 1b Interrupt Message Number: Hardwired to 0. Slot Implemented 0 = The PCI Express* Link associated with this port is connected to an integrated component or is disabled. 1 = The PCI Express Link associated with this port is connected to a slot. BIOS must initialize this field appropriately if a slot connection is not implemented. 7:4 3:0 RO 4h RO 1h Device/Port Type: Hardwired to 0100 to indicate root port of PCI Express Root Complex. PCI Express Capability Version: Hardwired to 1 as it is the first version. Description 15:14 13:9 8 150 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.33 DCAP—Device Capabilities (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 A4h 00000000h RO 32 bits This register indicates PCI Express link capabilities. Bit Access & Default Reserved RO 0b RO 00b RO 000b Extended Tag Field Supported: Hardwired to indicate support for 5-bit Tags as a Requestor. Phantom Functions Supported: Hardwired to 0. Max Payload Size: Hardwired to indicate 128B maximum supported payload for Transaction Layer Packets (TLP). Description 31:6 5 4:3 2:0 Datasheet 151 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.34 DCTL—Device Control (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 A8h 0000h R/W 16 bits This register provides control for PCI Express device specific capabilities. The error reporting enable bits are in reference to errors detected by this device, not error messages received across the link. The reporting of error messages (ERR_CORR, ERR_NONFATAL, ERR_FATAL) received by Root Port is controlled exclusively by Root Port Command Register. Bit Access & Default Reserved R/W 000b Max Payload Size 000 = 128B maximum supported payload for Transaction Layer Packets (TLP). As a receiver, the device must handle TLPs as large as the set value; as transmitter, the device must not generate TLPs exceeding the set value. Note: All other encodings are reserved. 4 3 R/W 0b Reserved Unsupported Request Reporting Enable: 0 = Disable. 1 = Enable. Unsupported Requests will be reported. Note that reporting of error messages received by Root Port is controlled exclusively by Root Control register. 2 R/W 0b Fatal Error Reporting Enable: 0 = Disable. 1 = Enable. Fatal errors will be reported. For a Root Port, the reporting of fatal errors is internal to the root. No external ERR_FATAL message is generated. 1 R/W 0b Non-Fatal Error Reporting Enable: 0 = Disable. 1 = Enable. Non-fatal errors will be reported. For a Root Port, the reporting of non-fatal errors is internal to the root. No external ERR_NONFATAL message is generated. Uncorrectable errors can result in degraded performance. 0 R/W 0b Correctable Error Reporting Enable: 0 = Disable. 1 = Enable. Correctable errors will be reported. For a Root Port, the reporting of correctable errors is internal to the root. No external ERR_CORR message is generated. Description 15:8 7:5 152 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.35 DSTS—Device Status (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 AAh 0000h RO 16 bits This register reflects status corresponding to controls in the Device Control register. Note: The error reporting bits are in reference to errors detected by this device, not errors messages received across the link. Bit Access & Default Reserved RO 0b Transactions Pending Description 15:6 5 0 = All pending transactions (including completions for any outstanding nonposted requests on any used virtual channel) have been completed. 1 = Device has transaction(s) pending (including completions for any outstanding non-posted requests for all used Traffic Classes). 4 3 R/WC 0b Reserved Unsupported Request Detected: 1 = Device received an Unsupported Request. Errors are logged in this register regardless of whether error reporting is enabled or not in the Device Control Register. Fatal Error Detected: 1 = Fatal error(s) were detected. Errors are logged in this register regardless of whether error reporting is enabled or not in the Device Control register. Non-Fatal Error Detected: 1 = Non-fatal error(s) were detected. Errors are logged in this register regardless of whether error reporting is enabled or not in the Device Control register. Correctable Error Detected: 1 = Correctable error(s) were detected. Errors are logged in this register regardless of whether error reporting is enabled or not in the Device Control register. Note: The (G)MCH may report a false 8B/10B Receiver Error when exiting L0s. This is reported thru the Correctable Error Detected bit CESTS device 1, offset 1D0h, Bit [0]. This will reduce the value of Receiver Error detection when L0s is enabled. Disable L0s for accurate Receiver Error reporting. 2 R/WC 0b 1 R/WC 0b 0 R/WC 0b Datasheet 153 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.36 LCAP—Link Capabilities (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 ACh 02012E01h R/WO 16 bits This register indicates PCI Express device specific capabilities. Bit Access & Default RO 02h Description 31:24 23:18 17:15 Port Number: This field indicates the PCI Express* port number for the given PCI Express link. This field matches the value in Element Self Description [31:24]. Reserved R/WO 010b L1 Exit Latency: This field indicates the length of time this Port requires to complete the transition from L1 to L0. The value 010 b indicates the range of 2 µs to less than 4 µs. If this field is required to be any value other than the default, BIOS must initialize it accordingly. Both bytes of this register that contain a portion of this field must be written simultaneously in order to prevent an intermediate (and undesired) value from ever existing. 14:12 R/WO 010b L0s Exit Latency: This field indicates the length of time this Port requires to complete the transition from L0s to L0. The value 010 b indicates the range of 128 ns to less than 256 ns. If this field is required to be any value other than the default, BIOS must initialize it accordingly. Note: When PCI Express* is operating with separate reference clocks, L0s exit latency may be greater than the setting in the L0s Exit Latency Register. Expect longer exit latency then setting in L0s Exit Latency Register. The link may enter Recovery state before reaching L0. System BIOS can program the appropriate Exit Latency and advertised N_FTS value if it detects that the downstream device is not using the common reference clock (indicated in the Slot Clock Configuration bit 12 of the device’s Link Status Register) 11:10 9:4 R/WO 11b RO 10h Active State Link PM Support: L0s & L1 entry supported. Max Link Width: Hardwired to indicate X16. When Force X1 mode is enabled on this PCI Express* x16 Graphics Interface device, this field reflects X1 (01h). Max Link Speed: Hardwired to indicate 2.5 Gb/s. 3:0 RO 1h 154 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.37 LCTL—Link Control (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 B0h 0000h RO, R/W 16 bits This register allows control of PCI Express link. Bit Access & Default Reserved R/W 0h R/W 0b Reserved. Must be 0 when writing this register. Common Clock Configuration 0 = This component and the component at the opposite end of this Link are operating with asynchronous reference clock. 1 = This component and the component at the opposite end of this Link are operating with a distributed common reference clock. Components use this common clock configuration information to report the correct L0s and L1 Exit Latencies. 5 R/W 0b Retrain Link 0 = Normal operation 1 = Full Link retraining is initiated by directing the Physical Layer LTSSM from L0, L0s, or L1 states to the Recovery state. This bit always returns 0 when read. This bit is cleared automatically (no need to write a 0). 4 R/W 0b Link Disable 0 = Normal operation 1 = Link is disabled. Forces the LTSSM to transition to the Disabled state (via Recovery) from L0, L0s, or L1 states. Link retraining happens automatically on 0 to 0 transition, just like when coming out of reset. Writes to this bit are immediately reflected in the value read from the bit, regardless of actual Link state. 3 2 1:0 R/W 00b RO 0b Read Completion Boundary (RCB): Hardwired to 0 to indicate 64 byte. Reserved Active State PM: This field controls the level of active state power management supported on the given link. 00 = Disabled 01 = L0s Entry Supported 10 = Reserved 11 = L0s and L1 Entry Supported Description 15:8 7 6 Datasheet 155 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.38 LSTS—Link Status (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 B2h 1001h RO 16 bits This register indicates PCI Express link status. Bit Access & Default Reserved RO 1b Slot Clock Configuration 0 = The device uses an independent clock irrespective of the presence of a reference on the connector. 1 = The device uses the same physical reference clock that the platform provides on the connector. 11 RO 0b Link Training: 1 = Link training is in progress. Hardware clears this bit once Link training is complete. Training Error: 1 = This bit is set by hardware upon detection of unsuccessful training of the Link to the L0 Link state. Negotiated Width: This field indicates negotiated link width. This field is valid only when the link is in the L0, L0s, or L1 states (after link width negotiation is successfully completed). 00h = Reserved 01h = X1 04h = Reserved 08h = Reserved 10h = X16 All other encodings are reserved. 3:0 RO 1h Negotiated Speed: This field indicates negotiated link speed. 1h = 2.5 Gb/s All other encodings are reserved. Description 15:13 12 10 RO 0b 9:4 RO 00h 156 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.39 SLOTCAP—Slot Capabilities (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 B4h 00000000h R/WO 32 bits PCI Express slot-related registers allow for the support of Hot-Plug. Bit Access & Default R/WO 0000h Description 31:19 Physical Slot Number: This field indicates the physical slot number attached to this Port. This field must be initialized by BIOS to a value that assigns a slot number that is globally unique within the chassis. 18:17 16:15 R/WO 00b Reserved Slot Power Limit Scale: This field specifies the scale used for the Slot Power Limit Value. 00 = 1.0x 01 = 0.1x 10 = 0.01x 11 = 0.001x If this field is written, the link sends a Set_Slot_Power_Limit message. 14:7 R/WO 00h Slot Power Limit Value: In combination with the Slot Power Limit Scale value, this field specifies the upper limit on power supplied by slot. Power limit (in Watts) is calculated by multiplying the value in this field by the value in the Slot Power Limit Scale field. If this field is written, the link sends a Set_Slot_Power_Limit message. 6 5 4 3 2:1 0 R/WO 0b R/WO 0b R/WO 0b R/WO 0b Hot-plug Capable: This field indicates that this slot is capable of supporting Hot-plug operations. Hot-plug Surprise: This field indicates that a device present in this slot might be removed from the system without any prior notification. Power Indicator Present: This field indicates that a Power Indicator is implemented on the chassis for this slot. Attention Indicator Present: This field indicates that an Attention Indicator is implemented on the chassis for this slot. Reserved R/WO 0b Attention Button Present: This field indicates that an Attention Button is implemented on the chassis for this slot. The Attention Button allows the user to request hot-plug operations. Datasheet 157 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.40 SLOTCTL—Slot Control (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 B8h 01C0h R/W 16 bits PCI Express slot related registers allow for the support of Hot-Plug. Bit Access & Default Reserved R/W 01b Power Indicator Control: Reads to this register return the current state of the Power Indicator. Writes to this register set the Power Indicator and cause the Port to send the appropriate POWER_INDICATOR_* messages. 00 = Reserved 01 = On 10 = Blink 11 = Off 7:6 R/W 11b Attention Indicator Control: Reads to this register return the current state of the Attention Indicator. Writes to this register set the Attention Indicator and cause the Port to send the appropriate ATTENTION_INDICATOR_* messages. 00 = Reserved 01 = On 10 = Blink 11 = Off 5 R/W 0b Hot plug Interrupt Enable: 0 = Disable. 1 = Enables generation of hot plug interrupt on enabled hot plug events. 4 R/W 0b Command Completed Interrupt Enable: 0 = Disable. 1 = Enables the generation of hot plug interrupt when the Hot plug controller completes a command. 3 R/W 0b Presence Detect Changed Enable: 0 = Disable. 1 = Enables the generation of hot plug interrupt or wake message on a presence detect changed event. 2:1 0 R/W 0b Reserved Attention Button Pressed Enable: 0 = Disable. 1 = Enables the generation of hot plug interrupt or wake message on an attention button pressed event. Description 15:10 9:8 158 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.41 SLOTSTS—Slot Status (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 BAh 0X00h RO, R/W/C 16 bits PCI Express slot-related registers allow for the support of Hot-Plug. Bit Access & Default Reserved RO Xb Presence Detect State: This bit indicates the presence of a card in the slot. 0 = Slot Empty 1 = Card Present in slot. Reserved R/WC 0b R/WC 0b Command Completed: 1 = Hot plug controller completed an issued command. Presence Detect Changed: 1 = Presence Detect change is detected. This corresponds to an edge on the signal that corresponds to bit 6 of this register (Presence Detect State). Reserved R/WC 0b Attention Button Pressed: 1 = Attention Button is pressed. Description 15:7 6 5 4 3 2:1 0 Datasheet 159 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.42 RCTL—Root Control (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 BCh 0000h R/W 16 bits This register allows control of PCI Express Root Complex specific parameters. The system error control bits in this register determine if corresponding SERRs are generated when our device detects an error (reported in this device’s Device Status register) or when an error message is received across the link. Reporting of SERR as controlled by these bits takes precedence over the SERR Enable in the PCI Command Register. Bit Access & Default Reserved R/W 0b PME Interrupt Enable Description 15:4 3 0 = No interrupts are generated as a result of receiving PME messages. 1 = Enables interrupt generation upon receipt of a PME message as reflected in the PME Status bit of the Root Status Register. A PME interrupt is also generated if the PME Status bit of the Root Status Register is set when this bit is set from a cleared state. 2 R/W 0b System Error on Fatal Error Enable: This bit controls the Root Complex’s response to fatal errors. 0 = No SERR generated on receipt of fatal error. 1 = Indicates that an SERR should be generated if a fatal error is reported by any of the devices in the hierarchy associated with this Root Port, or by the Root Port itself. 1 R/W 0b System Error on Non-Fatal Uncorrectable Error Enable: This bit controls the Root Complex’s response to non-fatal errors. 0 = No SERR generated on receipt of non-fatal error. 1 = Indicates that an SERR should be generated if a non-fatal error is reported by any of the devices in the hierarchy associated with this Root Port, or by the Root Port itself. 0 R/W 0b System Error on Correctable Error Enable: This bit controls the Root Complex’s response to correctable errors. 0 = No SERR generated on receipt of correctable error. 1 = Indicates that an SERR should be generated if a correctable error is reported by any of the devices in the hierarchy associated with this Root Port, or by the Root Port itself. 160 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.43 RSTS—Root Status (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 C0h 00000000h RO, R/W/C 32 bits This register provides information about PCI Express Root Complex specific parameters. Bit Access & Default Reserved RO 0b PME Pending: This bit indicates that another PME is pending when the PME Status bit is set. When the PME Status bit is cleared by software; the PME is delivered by hardware by setting the PME Status bit again and updating the Requestor ID appropriately. The PME pending bit is cleared by hardware if no more PMEs are pending. PME Status: This bit indicates that the requestor ID indicated in the PME Requestor ID field asserted PME. Subsequent PMEs are kept pending until the status register is cleared by writing a 1 to this field. PME Requestor ID: This field indicates the PCI requestor ID of the last PME requestor. Description 31:18 17 16 R/W/C 0b RO 0000h 15:0 Datasheet 161 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.44 PEGLC—PCI Express*-G Legacy Control PCI Device: Address Offset: Default Value: Access: Size: 1 ECh 00000000h RO, R/W 32 bits This register controls functionality that is needed by Legacy (non-PCI Express aware) OS’s during run time. Bit Access & Default RO 0000 0000h R/W 0b Reserved Description 31:3 2 PME GPE Enable (PMEGPE): 0 = Do not generate GPE PME message when PME is received. 1 = Enable. Generate a GPE PME message when PME is received (Assert_PMEGPE and Deassert_PMEGPE messages on DMI). This enables the (G)MCH to support PMEs on the PCI Express* x16 Graphics Interface port under legacy OSs. 1 R/W 0b Hot-Plug GPE Enable (HPGPE) 0 = Do not generate GPE Hot-Plug message when Hot-Plug event is received. 1 = Enable. Generate a GPE Hot-Plug message when Hot-Plug Event is received (Assert_HPGPE and Deassert_HPGPE messages on DMI). This enables the (G)MCH to support Hot-Plug on the PCI Express* x16 Graphics Interface port under legacy OSs. 0 R/W 0b General Message GPE Enable (GENGPE) 0 = Do not forward received GPE assert/deassert messages. 1 = Enable. Forward received GPE assert/deassert messages. These general GPE message can be received via the PCI Express* x16 Graphics Interface port from an external Intel device and will be subsequently forwarded to the ® Intel ICH6 (via Assert_GPE and Deassert_GPE messages on DMI). 162 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.45 VCECH—Virtual Channel Enhanced Capability Header (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 100h 14010002h RO 32 bits This register indicates PCI Express device Virtual Channel capabilities. Note: Extended capability structures for PCI Express devices are located in PCI Express extended configuration space and have different field definitions than standard PCI capability structures. Bit Access & Default RO 140h RO 1h RO 0002h Description 31:20 19:16 15:0 Pointer to Next Capability: The Link Declaration Capability is the next in the PCI Express* extended capabilities list. PCI Express Virtual Channel Capability Version: Hardwired to 1 to indicate compliances with the 1.0a version of the PCI Express specification. Extended Capability ID: Value of 0002 h identifies this linked list item (capability structure) as being for PCI Express Virtual Channel registers. 8.1.46 PVCCAP1—Port VC Capability Register 1 (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 104h 00000001h RO, R/WO 32 bits This register describes the configuration of PCI Express Virtual Channels associated with this port. Bit Access & Default Reserved RO 000b Low Priority Extended VC Count: This field indicates the number of (extended) Virtual Channels in addition to the default VC belonging to the low-priority VC (LPVC) group that has the lowest priority with respect to other VC resources in a strict-priority VC Arbitration. The value of 0 in this field implies strict VC arbitration. 3 2:0 R/WO 001b Reserved Extended VC Count: This field indicates the number of (extended) Virtual Channels in addition to the default VC supported by the device. Description 31:7 6:4 Datasheet 163 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.47 PVCCAP2—Port VC Capability Register 2 (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 108h 00000001h RO 32 bits This register describes the configuration of PCI Express Virtual Channels associated with this port. Bit Access & Default RO 00h Description 31:24 VC Arbitration Table Offset: This field indicates the location of the VC Arbitration Table. This field contains the zero-based offset of the table in DQWORDS (16 bytes) from the base address of the Virtual Channel Capability Structure. A value of 0 indicates that the table is not present (due to fixed VC priority). Reserved 23:8 7:0 RO 01h VC Arbitration Capability: This field indicates that the only possible VC arbitration scheme is hardware fixed (in the root complex). VC1 is the highest priority, VC0 is the lowest priority. 8.1.48 PVCCTL—Port VC Control (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: Bit Access & Default Reserved R/W 000b VC Arbitration Select: This field will be programmed by software to the only possible value as indicated in the VC Arbitration Capability field. The value 001b when written to this field will indicate the VC arbitration scheme is hardware fixed (in the root complex). This field can not be modified when more than one VC in the LPVC group is enabled. 0 Reserved 1 10Ch 0000h R/W 16 bits Description 15:4 3:1 164 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.49 VC0RCAP—VC0 Resource Capability (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 110h 00000000h RO 32 bits Bit Access & Default Reserved RO 0b Reject Snoop Transactions Description 31:16 15 0 = Transactions with or without the No Snoop bit set within the TLP header are allowed on this VC. 1 = Any transaction without the No Snoop bit set within the TLP header will be rejected as an Unsupported Request. 14:0 Reserved 8.1.50 VC0RCTL—VC0 Resource Control (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 114h 8000007Fh RO, R/W 32 bits This register controls the resources associated with PCI Express Virtual Channel 0. Bit Access & Default RO 1b Description 31 30:27 26:24 23:8 7:1 VC0 Enable: For VC0, this is hardwired to 1 and read only as VC0 can never be disabled. Reserved RO 000b VC0 ID: This field assigns a VC ID to the VC resource. For VC0 this is hardwired to 0 and read only. Reserved R/W 7Fh TC/VC0 Map: This field indicates the TCs (Traffic Classes) that are mapped to the VC resource. Bit locations within this field correspond to TC values. For example, when bit 7 is set in this field, TC7 is mapped to this VC resource. When more than one bit in this field is set, it indicates that multiple TCs are mapped to the VC resource. In order to remove one or more TCs from the TC/VC Map of an enabled VC, software must ensure that no new or outstanding transactions with the TC labels are targeted at the given Link. TC0/VC0 Map: Traffic Class 0 is always routed to VC0. 0 RO 1b Datasheet 165 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.51 VC0RSTS—VC0 Resource Status (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 11Ah 0000h RO 16 bits This register reports the Virtual Channel specific status. Bit Access & Default Reserved RO 1b VC0 Negotiation Pending 0 = The VC negotiation is complete. 1 = The VC resource is still in the process of negotiation (initialization or disabling). This bit indicates the status of the process of Flow Control initialization. It is set by default on Reset, as well as whenever the corresponding Virtual Channel is Disabled or the Link is in the DL_Down state. It is cleared when the link successfully exits the FC_INIT2 state Before using a Virtual Channel, software must check whether the VC Negotiation Pending fields for that Virtual Channel are cleared in both Components on a Link. 0 Reserved Description 15:2 1 8.1.52 VC1RCAP—VC1 Resource Capability (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 11Ch 00008000h RO 32 bits Bit Access & Default Reserved RO 1b Reject Snoop Transactions Description 31:16 15 0 = Transactions with or without the No Snoop bit set within the TLP header are allowed on this VC. 1 = Any transaction without the No Snoop bit set within the TLP header will be rejected as an Unsupported Request. 14:0 Reserved 166 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.53 VC1RCTL—VC1 Resource Control (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 120h 01000000h RO, R/W 32 bits Controls the resources associated with PCI Express Virtual Channel 1. Bit Access & Default R/W 0b VC1 Enable 0 = Virtual Channel is disabled. 1 = Virtual Channel is enabled. See exceptions in note below. Software must use the VC Negotiation Pending bit to check whether the VC negotiation is complete. When VC Negotiation Pending bit is cleared, a 1 read from this VC Enable bit indicates that the VC is enabled (Flow Control Initialization is completed for the PCI Express* port); a 0 read from this bit indicates that the Virtual Channel is currently disabled. Notes: • To enable a Virtual Channel, the VC Enable bits for that Virtual Channel must be set in both Components on a Link. • To disable a Virtual Channel, the VC Enable bits for that Virtual Channel must be cleared in both Components on a Link. • Software must ensure that no traffic is using a Virtual Channel at the time it is disabled. • Software must fully disable a Virtual Channel in both Components on a Link before re-enabling the Virtual Channel. 30:27 26:24 R/W 001b Reserved VC1 ID: Assigns a VC ID to the VC resource. Assigned value must be non-zero. This field cannot be modified when the VC is already enabled. Reserved R/W 00h TC/VC1 Map: This field indicates the TCs (Traffic Classes) that are mapped to the VC resource. Bit locations within this field correspond to TC values. For example, when bit 7 is set in this field, TC7 is mapped to this VC resource. When more than one bit in this field is set, it indicates that multiple TCs are mapped to the VC resource. In order to remove one or more TCs from the TC/VC Map of an enabled VC, software must ensure that no new or outstanding transactions with the TC labels are targeted at the given Link. TC0/VC1 Map: Traffic Class 0 is always routed to VC0. Description 31 23:8 7:1 0 RO 0b Datasheet 167 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.54 VC1RSTS—VC1 Resource Status (D1:F0) PCI Device: 1 Address Offset: 126h Default Value: 0000h Access: RO Size: 16 bits This register reports the Virtual Channel specific status. Bit Access & Default Reserved RO 1b VC1 Negotiation Pending 0 = The VC negotiation is complete. 1 = The VC resource is still in the process of negotiation (initialization or disabling). This bit indicates the status of the process of Flow Control initialization. It is set by default on Reset, as well as when the corresponding Virtual Channel is Disabled or the Link is in the DL_Down state. It is cleared when the link successfully exits the FC_INIT2 state Before using a Virtual Channel, software must check whether the VC Negotiation Pending fields for that Virtual Channel are cleared in both Components on a Link. 0 Reserved Description 15:2 1 8.1.55 RCLDECH—Root Complex Link Declaration Enhanced Capability Header (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 140h 00010005h RO 32 bits This capability declares links from this element (PCI Express* x16 Graphics Interface) to other elements of the root complex component to which it belongs. See the PCI Express specification for link/topology declaration requirements. Bit 31:20 Access & Default RO 000h 19:16 15:0 RO 1h RO 0005h Description Pointer to Next Capability: This is the last capability in the PCI Express* extended capabilities list. Link Declaration Capability Version: Hardwired to 1 to indicate compliances with the 1.0a version of the PCI Express specification. Extended Capability ID: Value of 0005h identifies this linked list item (capability structure) as being for PCI Express Link Declaration Capability. Note: See corresponding Egress Port Link Declaration Capability registers for diagram of Link Declaration Topology. 168 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.56 ESD—Element Self Description (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 144h 02000100h RO, R/WO 32 bits This register provides information about the root complex element containing this Link Declaration Capability. Bit Access & Default RO 02h Description 31:24 Port Number: This field specifies the port number associated with this element with respect to the component that contains this element. The egress port of the component to provide arbitration to this Root Complex Element uses this port number value. Component ID: This field indicates the physical component that contains this Root Complex Element. Component IDs start at 1. This value is a mirror of the value in the Component ID field of all elements in this component. The value only needs to be written in one of the mirrored fields and it will be reflected everywhere that it is mirrored. 23:16 R/WO 00h 15:8 RO 01h Number of Link Entries: This field indicates the number of link entries following the Element Self Description. This field reports 1 (to Egress port only as peer-topeer capabilities in this topology are not reported). Reserved 7:4 3:0 RO 0h Element Type: This field indicates the type of the Root Complex Element. 0h = root port. Datasheet 169 Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.57 LE1D—Link Entry 1 Description (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 150h 00000000h RO, R/WO 32 bits This register provides the First part of a Link Entry that declares an internal link to another Root Complex Element. Bit Access & Default RO 00h Description 31:24 Target Port Number: This field specifies the port number associated with the element targeted by this link entry (Egress Port). The target port number is with respect to the component that contains this element as specified by the target component ID. Target Component ID: This field indicates the physical or logical component that is targeted by this link entry. A value of 0 is reserved; Component IDs start at 1. This value is a mirror of the value in the Component ID field of all elements in this component. The value only needs to be written in one of the mirrored fields and it will be reflected everywhere that it is mirrored. 23:16 R/WO 00h 15:2 1 0 RO 0b R/WO 0b Reserved Link Type: This field indicates that the link points to memory-mapped space (for RCRB). The link address specifies the 64-bit base address of the target RCRB. Link Valid: 0 = Link Entry is not valid and will be ignored. 1 = Link Entry specifies a valid link. 170 Datasheet Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82915G/82915P/82915PL Only) R 8.1.58 LE1A—Link Entry 1 Address (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 158h 0000000000000000h R/WO 64 bits This register provides the second part of a Link Entry that declares an internal link to another Root Complex Element. Bit Access & Default Reserved R/WO 0 0000h Link Address: This field indicates memory-mapped base address of the RCRB that is the target element (Egress Port) for this link entry. Reserved Description 63:32 31:12 11:0 8.1.59 PEGSSTS—PCI Express*-G Sequence Status (D1:F0) PCI Device: Address Offset: Default Value: Access: Size: 1 218h 0000000000000FFFh RO 64 bits This register provides PCI Express status reporting that is required by the PCI Express specification. Bit Access & Default Reserved RO 000h Next Transmit Sequence Number: Value of the NXT_TRANS_SEQ counter. This counter represents the transmit Sequence number to be applied to the next TLP to be transmitted onto the Link for the first time. Reserved RO 000h Next Packet Sequence Number: Packet sequence number to be applied to the next TLP to be transmitted or re-transmitted onto the Link. Reserved RO 000h Next Receive Sequence Number: This is the sequence number associated with the TLP that is expected to be received next. Reserved RO FFFh Last Acknowledged Sequence Number: This is the sequence number associated with the last acknowledged TLP. Description 63:60 59:48 47:44 43:32 31:28 27:16 15:12 11:0 § Datasheet 171 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) Device 2 contains registers for the internal graphics functions. Table 9-1 lists the PCI configuration registers in order of ascending offset address. Function 0 can be VGA compatible or not, this is selected through bit 1 of GGC register (Device 0, offset 52h). The following sections describe Device 2 PCI configuration registers only. Table 9-1. Integrated Graphics Device Register Address Map (D2:F0) Address Offset 00–01h 02–03h 04–05h 06–07h 08h 09–0Bh 0Ch 0Dh 0Eh 0Fh 10–13h 14–17h 18–1Bh 1C–1Fh 20–2Bh 2C–2Dh 2E–2Fh 30–33h 34h 35–3Bh Register Symbol VID2 DID2 PCICMD2 PCISTS2 RID2 CC CLS MLT2 HDR2 — MMADR IOBAR GMADR GTTADR — SVID2 SID2 ROMADR CAPPOINT — Register Name Default Value 8086h 2582h 0000h 0090h See register description 030000h 00h 00h 80h — 00000000h 00000001h 00000008h 00000000h — 0000h 0000h 00000000h D0h — Access Vendor Identification Device Identification PCI Command PCI Status Revision Identification Class Code Cache Line Size Master Latency Timer Header Type Reserved Memory Mapped Range Address I/O Base Address Graphics Memory Range Address Graphics Translation Table Range Address Reserved Subsystem Vendor Identification Subsystem Identification Video BIOS ROM Base Address Capabilities Pointer Reserved RO RO RO, R/W RO RO RO RO RO RO — RO, R/W RO, R/W RO, R/W/L RO, R/W — R/WO R/WO RO RO — Datasheet 173 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R Address Offset 3Ch 3Dh 3Eh 3Fh 40–43h 44h 45–47h 48–50h 51h 52–53h 54–57h 58–5Bh 5C–5Fh 60–61h 62h 63–CFh D0–D1h D2–D3h D4–D5h D6–D7h E0–E1h E2–E3h E4–E7 E8h–FBh FC–FFh Register Symbol INTRLINE INTRPIN MINGNT MAXLAT — MCAPPTR — MCAPID — MGGC MDEVENde v0F0 — BSM — MSAC — PMCAPID PMCAP PMCS — SWSMI — ASLE — ASLS Interrupt Line Interrupt Pin Register Name Default Value 00h 01h 00h 00h — D0h — 0000000000 01090009h — 0030h 00000019h — 07800000h — 00h — 0001h 0022h 0000h — 0000h — 00000000h — 00000000h Access R/W RO RO RO — RO — RO — RO RO — RO — R/W — RO RO RO, R/W — R/W — R/W — R/W Minimum Grant Maximum Latency Reserved Mirror of Dev0 Capability Pointer Reserved Mirror of Dev0 Capability Identification Reserved Mirror of Dev0 GMCH Graphics Control Mirror of Dev0 Device Enable Reserved Base of Stolen Memory Reserved Multi size Aperture Control Reserved Power Management Capabilities ID Power Management Capabilities Power Management Control/Status Reserved Software SMI Reserved System Display Event Reserved ASL Storage 174 Datasheet Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1 9.1.1 Integrated Graphics Device PCI Register Details (D2:F0) VID2—Vendor Identification (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 00h 8086h RO 16 bits This register, combined with the Device Identification register, uniquely identifies any PCI device. Bit Access & Default RO 8086h Description 15:0 Vendor Identification Number (VID): PCI standard identification for Intel. 9.1.2 DID2—Device Identification (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 02h 2582h RO 16 bits This register, combined with the Vendor Identification register, uniquely identifies any PCI device. Bit Access & Default RO 2582h Description 15:0 Device Identification Number (DID): This is a 16 bit value assigned to the GMCH Graphic device Datasheet 175 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.3 PCICMD2—PCI Command (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 04h 0000h RO, R/W 16 bits This 16-bit register provides basic control over the IGD’s ability to respond to PCI cycles. The PCICMD Register in the IGD disables the IGD PCI compliant master accesses to main memory. Bit Access & Default Reserved R/W 0b Description 15:11 10 Interrupt Disable: This bit disables the device from asserting INTx#. 0 = Enable the assertion of this device’s INTx# signal. 1 = Disable the assertion of this device’s INTx# signal. DO_INTx messages will not be sent to the DMI. 9 8 7 6 RO 0b RO 0b RO 0b RO 0b Fast Back-to-Back (FB2B): Not Implemented. Hardwired to 0. SERR Enable (SERRE): Not Implemented. Hardwired to 0. Address/Data Stepping Enable (ADSTEP): Not Implemented. Hardwired to 0. Parity Error Enable (PERRE): Not Implemented. Hardwired to 0. Since the IGD belongs to the category of devices that does not corrupt programs or data in system memory or hard drives, the IGD ignores any parity error that it detects and continues with normal operation. Video Palette Snooping (VPS): This bit is hardwired to 0 to disable snooping. Memory Write and Invalidate Enable (MWIE): Hardwired to 0. The IGD does not support memory write and invalidate commands. Special Cycle Enable (SCE): This bit is hardwired to 0. The IGD ignores Special cycles. Bus Master Enable (BME): 0 = Disable IGD bus mastering. 1 = Enable the IGD to function as a PCI compliant master. Memory Access Enable (MAE): This bit controls the IGD’s response to memory space accesses. 0 = Disable. 1 = Enable. 5 4 3 2 RO 0b RO 0b RO 0b R/W 0b 1 R/W 0b 0 R/W 0b I/O Access Enable (IOAE): This bit controls the IGD’s response to I/O space accesses. 0 = Disable. 1 = Enable. 176 Datasheet Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.4 PCISTS2—PCI Status (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 06h 0090h RO 16 bits PCISTS is a 16-bit status register that reports the occurrence of a PCI compliant master abort and PCI compliant target abort. PCISTS also indicates the DEVSEL# timing that has been set by the IGD. Bit Access & Default RO 0b RO 0b RO 0b RO 0b RO 0b RO 00b RO 0b RO 1b RO 0b RO 0b RO 1b RO 0b Description 15 14 13 12 11 10:9 8 Detected Parity Error (DPE): Since the IGD does not detect parity; this bit is always hardwired to 0. Signaled System Error (SSE): The IGD never asserts SERR#, therefore this bit is hardwired to 0. Received Master Abort Status (RMAS): The IGD never gets a Master Abort, therefore, this bit is hardwired to 0. Received Target Abort Status (RTAS): The IGD never gets a Target Abort, therefore this bit is hardwired to 0. Signaled Target Abort Status (STAS): Hardwired to 0. The IGD does not use target abort semantics. DEVSEL Timing (DEVT): N/A. These bits are hardwired to 00. Master Data Parity Error Detected (DPD): Since Parity Error Response is hardwired to disabled (and the IGD does not do any parity detection), this bit is hardwired to 0. Fast Back-to-Back (FB2B): Hardwired to 1. The IGD accepts fast back-to-back when the transactions are not to the same agent. User Defined Format (UDF). Hardwired to 0. 66 MHz PCI Capable (66C). N/A; Hardwired to 0. Capability List (CLIST): 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. Interrupt Status: This bit reflects the state of the interrupt in the device. Only when the Interrupt Disable bit in the command register is a 0 and this Interrupt Status bit is a 1, will the devices INTx# signal be asserted. Setting the Interrupt Disable bit to a 1 has no effect on the state of this bit. Reserved 7 6 5 4 3 2:0 Datasheet 177 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.5 RID2—Revision Identification (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 08h See bit description RO 8 bits This register contains the revision number for Device 2 Functions 0 and 1 Bit Access & Default RO 00h Description 7:0 Revision Identification Number (RID): This field indicates the number of times that this device in this component has been “stepped” through the manufacturing ® process. Refer to the Intel 82915G/82915P/82915GV/82910GL Express Chipset Specification Update for the value of the Revision ID Register. 9.1.6 CC—Class Code (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 09h 030000h RO 24 bits This register contains the device programming interface information related to the Sub-Class Code and Base Class Code definition for the IGD. This register also contains the Base Class Code and the function sub-class in relation to the Base Class Code. Bit Access & Default RO 03h Description 23:16 Base Class Code (BCC). This is an 8-bit value that indicates the base class code for the GMCH. 03h = Display Controller. 15:8 RO 00h Sub-Class Code (SUBCC): Value will be determined based on Device 0 GGC register, bit 1. 00h = VGA compatible 80h = Non VGA 7:0 RO 00 h Programming Interface (PI) 00h = Hardwired as a Display controller. 178 Datasheet Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.7 CLS—Cache Line Size (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 0Ch 00h RO 8 bits The IGD does not support this register as a PCI slave. Bit Access & Default RO 00h Description 7:0 Cache Line Size (CLS): This field is hardwired to 0s. The IGD, 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. 9.1.8 MLT2—Master Latency Timer (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 0Dh 00h RO 8 bits The IGD does not support the programmability of the master latency timer because it does not perform bursts. Bit Access & Default RO 00h Description 7:0 Master Latency Timer Count Value: Hardwired to 0s. Datasheet 179 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.9 HDR2—Header Type (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 0Eh 80h RO 8 bits This register contains the Header Type of the IGD. Bit Access & Default RO 1b RO 00h Description 7 Multi Function Status (MFunc): This bit indicates if the device is a MultiFunction Device. The Value of this register is determined by Device 0, offset 54h, DEVEN[4]. If Device 0 DEVEN[4] is set, the Mfunc bit is also set. Header Code (H): This is a 7-bit value that indicates the Header Code for the IGD. This code has the value 00h, indicating a type 0 configuration space format. 6:0 9.1.10 MMADR—Memory Mapped Range Address (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 10h 00000000h RO, R/W 32 bits This register requests allocation for the IGD registers and instruction ports. The allocation is for 512 KB and the base address is defined by bits [31:19]. Bit Access & Default R/W 0000h RO 0000h RO 0b RO 00b RO 0b Description 31:19 18:4 3 2:1 0 Memory Base Address: Set by the OS, these bits correspond to address signals [31:19]. Address Mask: Hardwired to 0s to indicate 512 KB address range. Prefetchable Memory: Hardwired to 0 to prevent prefetching. Memory Type: Hardwired to 0s to indicate 32-bit address. Memory / IO Space: Hardwired to 0 to indicate memory space. 180 Datasheet Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.11 IOBAR—I/O Base Address (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 14h 00000001h RO, R/W 32 bits This register provides the Base offset of the I/O registers within Device 2. Bits 15:3 are programmable allowing the I/O Base to be located anywhere in 16 bit I/O address space. Bits 2:1 are fixed and return 0s; bit 0 is hardwired to a 1 indicating that 8 bytes of I/O space are decoded. Access to the 8Bs of I/O space is allowed in PM state D0 when IO Enable (PCICMD bit 0) set. Access is disallowed in PM states D1–D3 or if IO Enable is clear or if Device 2 is turned off. Note that access to this I/O BAR is independent of VGA functionality within Device 2. Also note that this mechanism in available only through function 0 of Device 2 and is not duplicated in Function 1. If accesses to this I/O bar are allowed, the GMCH claims all 8, 16, or 32 bit I/O cycles from the processor that falls within the 8B claimed. Bit Access & Default Reserved R/W 0000h RO 00b RO 1b IO Base Address: Set by the OS, these bits correspond to address signals [15:3]. Memory Type: Hardwired to 0s to indicate 32-bit address. Memory / I/O Space: Hardwired to 1 to indicate I/O space. Description 31:16 15:3 2:1 0 Datasheet 181 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.12 GMADR—Graphics Memory Range Address (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 18h 00000008h RO, R/W/L 16 bits IGD graphics memory base address is specified in this register. Bit Access & Default R/W 0h R/W/L 0b RO 000000h RO 1b RO 00b RO 0b Description 31:28 27 Memory Base Address: Set by the OS, these bits correspond to address signals [31:28]. 256-MB Address Mask: This bit is either part of the Memory Base Address (R/W) or part of the Address Mask (RO), depending on the value of MSAC[1]. See MSAC (Dev 2, Func 0, offset 62) for details. Address Mask: Hardwired to 0s to indicate at least 128-MB address range Prefetchable Memory: Hardwired to 1 to enable prefetching Memory Type: Hardwired to 0 to indicate 32-bit address. Memory/IO Space: Hardwired to 0 to indicate memory space. 26:4 3 2:1 0 182 Datasheet Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.13 GTTADR—Graphics Translation Table Range Address (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 1Ch 00000000h RO, R/W 32 bits This register requests allocation for Graphics Translation Table Range. The allocation is for 256 KB and the base address is defined by bits [31:18]. Bit Access & Default R/W 0000h RO 0000h RO 0b RO 00b RO 0b Description 31:18 17:4 3 2:1 0 Memory Base Address: Set by the OS, these bits correspond to address signals [31:18]. Address Mask: Hardwired to 0s to indicate 256-KB address range. Prefetchable Memory: Hardwired to 0 to prevent prefetching. Memory Type: Hardwired to 0s to indicate 32-bit address. Memory/IO Space: Hardwired to 0 to indicate memory space. 9.1.14 SVID2—Subsystem Vendor Identification (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 2Ch 0000h R/WO 16 bits Bit Access & Default R/WO 0000h Description 15:0 Subsystem Vendor ID. This value is used to identify the vendor of the subsystem. This register should be programmed by BIOS during boot-up. Once written, this register becomes Read-Only. This register can only be cleared by a Reset. Datasheet 183 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.15 SID2—Subsystem Identification (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 2Eh 0000h R/WO 16 bits Bit Access & Default R/WO 0000h Description 15:0 Subsystem Identification: This value is used to identify a particular subsystem. This field should be programmed by BIOS during boot-up. Once written, this register becomes Read Only. This register can only be cleared by a Reset. 9.1.16 ROMADR—Video BIOS ROM Base Address (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 30h 00000000h RO 32 bits The IGD does not use a separate BIOS ROM; therefore, this register is hardwired to 0s. Bit Access & Default RO 0000h RO 00h Description 31:18 17:11 10:1 0 ROM Base Address: Hardwired to 0s. Address Mask: Hardwired to 0s to indicate 256-KB address range. Reserved RO 0b ROM BIOS Enable: 0 = ROM not accessible. 184 Datasheet Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.17 CAPPOINT—Capabilities Pointer (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 34h D0h RO 8 bits Bit Access & Default RO D0h Description 7:0 Capabilities Pointer Value: This field contains an offset into the function’s PCI configuration space for the first item in the New Capabilities Linked List; the Power Management Capabilities ID registers at address D0h. 9.1.18 INTRLINE—Interrupt Line (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 3Ch 00h R/W 8 bits Bit Access & Default R/W 00h Description 7:0 Interrupt Connection: This field is used to communicate interrupt line routing information. POST software writes the routing information into this register as it initializes and configures the system. The value in this register indicates which input of the system interrupt controller that the device’s interrupt pin is connected to. 9.1.19 INTRPIN—Interrupt Pin (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 3Dh 01h RO 8 bits Bit Access & Default RO 01h Description 7:0 Interrupt Pin: As a device that only has interrupts associated with a single function, the IGD specifies INTA# as its interrupt pin. 01h = INTA#. Datasheet 185 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.20 MINGNT—Minimum Grant (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 3Eh 00h RO 8 bits Bit Access & Default RO 00h Description 7:0 Minimum Grant Value: The IGD does not burst as a PCI compliant master. 9.1.21 MAXLAT—Maximum Latency (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 3Fh 00h RO 8 bits Bit Access & Default RO 00h Description 7:0 Maximum Latency Value: The IGD has no specific requirements for how often it needs to access the PCI bus. 9.1.22 MCAPPTR—Mirror of Dev0 Capability Pointer (D2:F0) (Mirrored_D0_34) PCI Device: Function: Address Offset: Size: 2 0 44h 8 bits This register is a Read-Only copy of Device 0, Offset 34h register. 9.1.23 MCAPID—Mirror of Dev0 Capability Identification (D2:F0) (Mirrored_D0_E0) PCI Device: Function: Address Offset: Size: 2 0 48h 72 bits This register is a Read-Only copy of Device 0, Offset E0h register. 186 Datasheet Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.24 MGGC—Mirror of Dev0 GMCH Graphics Control (D2:F0) (Mirrored_D0_52) PCI Device: Function: Address Offset: Size: 2 0 52h 16 bits This register is a Read-Only copy of Device 0, Offset 52h register. 9.1.25 MDEVENdev0f0—Mirror of Dev0 Device Enable (D2:F0) (Mirrored_D0_54) PCI Device: Function: Address Offset: Size: 2 0 54h 32 bits This register is a Read-Only copy of Device 0, Offset 54h register. 9.1.26 BSM—Base of Stolen Memory (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 5Ch 07800000h RO 32 bits Graphics Stolen Memory and TSEG are within DRAM space defined under TOLUD. From the top of low used DRAM, GMCH claims 1 to 64 MBs of DRAM for internal graphics, if enabled. Bit Access & Default RO 078h Description 31:20 Base of Stolen Memory (BSM): This register contains bits 31:20 of the base address of stolen DRAM memory. The host interface determines the base of Graphics Stolen memory by subtracting the graphics stolen memory size from TOLUD. See Device 0 TOLUD for more explanation. Reserved 19:0 Datasheet 187 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.27 MSAC—Multi Size Aperture Control (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 62h 00h R/W 8 bits This register determines the size of the graphics memory aperture in function 0 and in the trusted space. By default, the aperture size is 256 MB (bit 27 read only). If bit 1 is set to a 1, then the aperture size is limited to 128 MB. Only the system BIOS will write this register based on preboot address allocation efforts, but the graphics may read this register to determine the correct aperture size. System BIOS needs to save this value on boot so that it can reset it correctly during S3 resume. Bit Access & Default R/W 0h Description 7:4 3:2 1 Scratch Bits Only. These bits have no physical effect on hardware. Reserved R/W 0b 256-MB Aperture Disable 0 = Bit 27 of GMADR and the equivalent trusted memory aperture is read-only, allowing 256 MB of address space to be mapped. 1 = Bit 27 of GMADR and the equivalent trusted memory aperture is read-write, limiting the address space to 128 MB. 0 Reserved 9.1.28 PMCAPID—Power Management Capabilities ID (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 D0h 0001h RO 16 bits Bit Access & Default RO 00h RO 01h Description 15:8 7:0 NEXT_PTR: This field contains a pointer to next item in capabilities list. This is the final capability in the list and must be set to 00h. CAP_ID: SIG defines this ID is 01h for power management. 188 Datasheet Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.29 PMCAP—Power Management Capabilities (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 D2h 0022h RO 16 bits Bit Access & Default RO 00h RO 0b RO 0b Description 15:11 10 9 8:6 5 4 3 2:0 PME Support: This field indicates the power states in which the IGD may assert PME#. Hardwired to 0 to indicate that the IGD does not assert the PME# signal. D2: The D2 power management state is not supported. This bit is hardwired to 0. D1: Hardwired to 0 to indicate that the D1 power management state is not supported. Reserved RO 1b RO 0b RO 0b RO 010b Device Specific Initialization (DSI): Hardwired to 1 to indicate that special initialization of the IGD is required before generic class device driver is to use it. Auxiliary Power Source: Hardwired to 0. PME Clock: Hardwired to 0 to indicate IGD does not support PME# generation. Version: Hardwired to 010b to indicate that there are 4 bytes of power management registers implemented and that this device complies with revision 1.1 of the PCI Power Management Interface Specification Datasheet 189 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.30 PMCS—Power Management Control/Status (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 D4h 0000h RO, R/W 16 bits Bit Access & Default RO 0b Description 15 14:9 8 7:2 1:0 PME_Status: This bit is 0 to indicate that IGD does not support PME# generation from D3 (cold). Reserved RO 0b PME_En: This bit is 0 to indicate that PME# assertion from D3 (cold) is disabled. Reserved R/W 00b Power State: This field indicates the current power state of the IGD and can be used to set the IGD into a new power state. If software attempts to write an unsupported state to this field, the write operation must complete normally on the bus, but the data is discarded and no state change occurs. On a transition from D3 to D0 the graphics controller is optionally reset to initial values. Behavior of the graphics controller in supported states is detailed in the power management section. 00 = D0 (Default) 01 = D1 (Not Supported) 10 = D2 (Not Supported) 11 = D3 190 Datasheet Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.31 SWSMI—Software SMI (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 E0h 0000h R/W 16 bits As long as there is the potential that DVO port legacy drivers exist that expect this register at this address, Dev2, F0, address E0h–E1h must be reserved for this register. Bit Access & Default R/W 00h R/W 00h R/W 0b SW scratch bits Software Flag: This field is used to indicate caller and SMI function desired, as well as return result. GMCH Software SMI Event: When Set, this bit will trigger an SMI. Software must write a 0 to clear this bit Description 15:8 7:1 0 9.1.32 ASLE—System Display Event Register (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 E4h 00000000h R/W 32 bits Byte, Word, or Double Word PCI configuration cycles can access this register. Bit Access & Default R/W 00h R/W 00h R/W 00h R/W 00h Description 31:8 ASLE Scratch Trigger 3: When written, this scratch byte triggers an interrupt when IER bit 0 is enabled and IMR bit 0 is unmasked. If written as part of a 16bit or 32-bit write, only one interrupt is generated in common. ASLE Scratch Trigger 2: When written, this scratch byte triggers an interrupt when IER bit 0 is enabled and IMR bit 0 is unmasked. If written as part of a 16bit or 32-bit write, only one interrupt is generated in common. ASLE Scratch Trigger 1: When written, this scratch byte triggers an interrupt when IER bit 0 is enabled and IMR bit 0 is unmasked. If written as part of a 16bit or 32-bit write, only one interrupt is generated in common. ASLE Scratch Trigger 0: When written, this scratch byte triggers an interrupt when IER bit 0 is enabled and IMR bit 0 is unmasked. If written as part of a 16bit or 32-bit write, only one interrupt is generated in common. 23:16 15:8 7:0 Datasheet 191 Integrated Graphics Device Registers (D2:F0) (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) R 9.1.33 ASLS—ASL Storage (D2:F0) PCI Device: Address Offset: Default Value: Access: Size: 2 FCh 00000000h R/W 32 bits This SW scratch register only needs to be read/write accessible. The exact bit register usage must be worked out in common between System BIOS and driver software, but storage for switching/indicating up to 6 devices is possible with this amount. For each device, the ASL control method requires two bits for _DOD (BIOS detectable yes or no, VGA/Non VGA); one bit for _DGS (enable/disable requested) and two bits for _DCS (enabled now/disabled now, connected or not). Bit Access & Default R/W 00000000 h Description 31:0 RW according to a software controlled usage to support device switching 192 Datasheet Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10 Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) Table 10-1. Device 2 Function 1 Register Address Map Summary Address Offset 00–01h 02–03h 04–05h 06–07h 08h 09–0Bh 0Ch 0Dh 0Eh 0Fh 10–13h 14–2Bh 2C–2Dh 2E–2Fh 30–33h 34h 35–3Dh 3Eh 3Fh 40–43h 44h 45–47h Register Symbol VID2 DID2 PCICMD2 PCISTS2 RID2 CC CLS MLT2 HDR2 — MMADR — SVID2 SID2 ROMADR CAPPOINT — MINGNT MAXLAT — MCAPPTR — Register Name Default Value 8086h 2780h 0000h 0090h See register description 03800h 00h 00h 80h — 00000000h — 0000h 0000h 00000000h D0h — 00h 00h — Access Vendor Identification Device Identification PCI Command PCI Status Revision Identification Class Code Register Cache Line Size Master Latency Timer Header Type Register Reserved Memory Mapped Range Address Reserved Subsystem Vendor Identification Subsystem Identification Video BIOS ROM Base Address Capabilities Pointer Reserved Minimum Grant Register Maximum Latency Reserved Mirror of Dev0 Capability Pointer Reserved RO RO RO, R/W RO RO RO RO RO RO — RO, R/W — R/WO R/WO RO RO — RO RO — — — Datasheet 193 Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R Address Offset 48–50h 51h 52–53h 54–57h 58–5Bh 5C–5Fh 60–CFh D0–D1h D2–D3h D4–D5h D6–DFh E0–E1h E2–FBh FC–FFh Register Symbol MCAPID — MGGC MDEVENdev0f0 — BSM — PMCAPID PMCAP PMCS — SWSMI — ASLS Register Name Default Value Access Mirror of Dev0 Capability Identification Reserved Mirror of Dev0 GMCH Graphics Control Mirror of Dev0 Device Enable Reserved Base of Stolen Memory Register Reserved Power Management Capabilities ID Power Management Capabilities Power Management Control/Status Reserved Software SMI Reserved ASL Storage — 07800000h 0000h 0001h 0022h 0000h — 0000h — 00000000h — RO — RO RO RO, R/W — R/W — R/W — — 10.1 10.1.1 Device 2 Function 1 Configuration Register Details (D2:F1) VID2—Vendor Identification (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 00h 8086h RO 16 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 10.1.2 DID2—Device Identification (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 02h 2782h RO 16 bits This register is unique in Device 2, Function 1 (the Device 2, Function 0 DID is separate). This difference in Device ID is necessary for allowing distinct Plug and Play enumeration of function 1 when both function 0 and function 1 have the same class code. 194 Datasheet Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10.1.3 PCICMD2—PCI Command (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 04h 0000h RO, R/W 16 bits This 16-bit register provides basic control over the IGD’s ability to respond to PCI cycles. The PCICMD Register in the IGD disables the IGD PCI compliant master accesses to main memory. Bit Access & Default Reserved RO 0b RO 0b RO 0b RO 0b Fast Back-to-Back (FB2B): Not Implemented. Hardwired to 0. SERR Enable (SERRE): Not Implemented. Hardwired to 0. Address/Data Stepping Enable (ADSTEP): Not Implemented. Hardwired to 0. Parity Error Enable (PERRE): Not Implemented. Hardwired to 0. Since the IGD belongs to the category of devices that does not corrupt programs or data in system memory or hard drives, the IGD ignores any parity error that it detects and continues with normal operation. VGA Palette Snoop Enable (VGASNOOP): This bit is hardwired to 0 to disable snooping. Memory Write and Invalidate Enable (MWIE): Hardwired to 0. The IGD does not support memory write and invalidate commands. Special Cycle Enable (SCE): This bit is hardwired to 0. The IGD ignores Special cycles. Bus Master Enable (BME): 0 = Disable 1 = Enable the IGD to function as a PCI compliant master. 1 R/W 0b Memory Access Enable (MAE): This bit controls the IGD’s response to memory space accesses. 0 = Disable. 1 = Enable. 0 R/W 0b I/O Access Enable (IOAE): This bit controls the IGD’s response to I/O space accesses. 0 = Disable. 1 = Enable. Description 15:10 9 8 7 6 5 4 3 2 RO 0b RO 0b RO 0b R/W 0b Datasheet 195 Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10.1.4 PCISTS2—PCI Status (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 06h 0090h RO 16 bits PCISTS is a 16-bit status register that reports the occurrence of a PCI compliant master abort and PCI compliant target abort. PCISTS also indicates the DEVSEL# timing that has been set by the IGD. Bit Access & Default RO 0b RO 0b RO 0b RO 0b RO 0b RO 00b RO 0b RO 1b RO 0b RO 0b RO 1b RO 0b Description 15 14 13 12 11 10:9 8 Detected Parity Error (DPE): Since the IGD does not detect parity; this bit is always hardwired to 0. Signaled System Error (SSE): The IGD never asserts SERR#; therefore, this bit is hardwired to 0. Received Master Abort Status (RMAS): The IGD never gets a Master Abort, therefore this bit is hardwired to 0. Received Target Abort Status (RTAS): The IGD never gets a Target Abort, therefore this bit is hardwired to 0. Signaled Target Abort Status (STAS): Hardwired to 0. The IGD does not use target abort semantics. DEVSEL Timing (DEVT): These bits are hardwired to 00. Master Data Parity Error Detected (DPD): Since Parity Error Response is hardwired to disabled (and the IGD does not do any parity detection), this bit is hardwired to 0. Fast Back-to-Back (FB2B): Hardwired to 1. The IGD accepts fast back-to-back when the transactions are not to the same agent. User Defined Format (UDF). Hardwired to 0. 66 MHz PCI Capable (66C). Hardwired to 0. Capability List (CLIST): 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. Interrupt Status: Hardwired to 0. Reserved 7 6 5 4 3 2:0 196 Datasheet Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10.1.5 RID2—Revision Identification (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 08h See description below RO 8 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 10.1.6 CC—Class Code Register (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 09h 038000h RO 24 bits This register contains the device programming interface information related to the Sub-Class Code and Base Class Code definition for the IGD. This register also contains the Base Class Code and the function sub-class in relation to the Base Class Code. Bit Access & Default RO 03h Description 23:16 Base Class Code (BCC): This is an 8-bit value that indicates the base class code for the GMCH. 03h = Display Controller. 15:8 RO 80h RO 00h Sub-Class Code (SUBCC) 80h = Non VGA Programming Interface (PI) 00h = Hardwired as a Display controller. 7:0 10.1.7 CLS—Cache Line Size (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 0Ch 00h RO 8 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. Datasheet 197 Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10.1.8 MLT2—Master Latency Timer (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 0Dh 00h RO 8 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 10.1.9 HDR2—Header Type Register (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 0Eh 80h RO 8 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 10.1.10 MMADR—Memory Mapped Range Address (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 10h 00000000h RO, R/W 32 bits This register requests allocation for the IGD registers and instruction ports. The allocation is for 512 KB and the base address is defined by bits [31:19]. Bit Access & Default R/W 0000h RO 0000h RO 0b RO 00b RO 0b Description 31:19 18:4 3 2:1 0 Memory Base Address: Set by the OS, these bits correspond to address signals [31:19]. Address Mask: Hardwired to 0s to indicate 512-KB address range. Prefetchable Memory: Hardwired to 0 to prevent prefetching. Memory Type: Hardwired to 0s to indicate 32-bit address. Memory / IO Space: Hardwired to 0 to indicate memory space. 198 Datasheet Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10.1.11 SVID2—Subsystem Vendor Identification (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 2Ch 0000h R/WO 16 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 10.1.12 SID2—Subsystem Identification (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 2Eh 0000h R/WO 16 bits This register is a Read Only copy of Device 2, Function 0. 10.1.13 ROMADR—Video BIOS ROM Base Address (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 30h 00000000h RO 32 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 10.1.14 CAPPOINT—Capabilities Pointer (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 34h D0h RO 8 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. Datasheet 199 Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10.1.15 MINGNT—Minimum Grant Register (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 3Eh 00h RO 8 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 10.1.16 MAXLAT—Maximum Latency (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 3Fh 00h RO 8 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 10.1.17 MCAPPTR—Mirror of Dev0 Capability Pointer (D2:F1) (Mirrored_D0_34) PCI Device: Function: Address Offset: Size: 2 1 44h 8 bits This register is a Read Only copy of Device 0, Offset 34h register. 10.1.18 MCAPID—Mirror of Dev0 Capability Identification (D2:F1) (Mirrored_D0_E0) PCI Device: Function: Address Offset: Size: 2 1 48h 72 bits This register is a Read-Only copy of Device 0, Offset E0h register. 10.1.19 MGGC—Mirror of Dev0 GMCH Graphics Control (D2:F1) (Mirrored_D0_52) PCI Device: Address Offset: Size: 2 52h 16 bits This register is a Read Only copy of Device 0, Offset 52h register. 200 Datasheet Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10.1.20 MDEVENdev0f0—Mirror of Dev0 Device Enable (D2:F1) (Mirrored_D0_54) PCI Device: Function: Address Offset: Size: 2 1 54h 32 bits This register is a Read Only copy of Device 0, Offset 54h register. 10.1.21 BSM—Base of Stolen Memory Register (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 5Ch 07800000h RO 32 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 10.1.22 PMCAPID—Power Management Capabilities ID (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 D0h 0001h RO 16 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 10.1.23 PMCAP—Power Management Capabilities (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 D2h 0022h RO 16 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. Datasheet 201 Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10.1.24 PMCS—Power Management Control/Status (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: Bit Access & Default RO 0b 2 D4h 0000h RO, R/W 16 bits Description 15 14:9 8 7:2 1:0 PME_Status: This bit is 0 to indicate that IGD does not support PME# generation from D3 (cold). Reserved RO 0b PME_En: This bit is 0 to indicate that PME# assertion from D3 (cold) is disabled. Reserved R/W 00 b Power State: This field indicates the current power state of the IGD and can be used to set the IGD into a new power state. If software attempts to write an unsupported state to this field, write operation must complete normally on the bus, but the data is discarded and no state change occurs. On a transition from D3 to D0 the graphics controller is optionally reset to initial values. Behavior of the graphics controller in supported states is detailed in the power management section. 00 = D0 (Default) 01 = D1 (Not Supported) 10 = D2 (Not Supported) 11 = D3 10.1.25 SWSMI—Software SMI (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 E0h 0000h R/W 16 bits This register is a copy of Device 2, Function 0. It has the same Read, Write attributes as D2:F0. It is implemented as common hardware with two access addresses. 202 Datasheet Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10.1.26 ASLS—ASL Storage (D2:F1) PCI Device: Address Offset: Default Value: Access: Size: 2 FCh 00000000h R/W 32 bits This software scratch register only needs to be read/write accessible. The exact bit register usage must be worked out in common between System BIOS and driver software, but storage for switching/indicating up to 6 devices is possible with this amount. For each device, the ASL control method with require two bits for _DOD (BIOS detectable yes or no, VGA/NonVGA), one bit for _DGS (enable/disable requested), and two bits for _DCS (enabled now/disabled now, connected or not). Bit Access & Default R/W 00000000 h Description 31:0 R/W according to a software controlled usage to support device switching Datasheet 203 Device 2 Function 1 (D2:F1) Configuration Registers (Intel® 82915G/82915GV/82915GL/ 82910GL Only) R 10.2 Device 2 – PCI I/O Registers The following are not PCI configurations registers; they are I/O registers. 10.2.1 MMIO_INDEX—MMIO Address Register I/O Address: Size: IOBAR + 0h 32 bits MMIO_INDEX: A 32 bit I/O write to this port loads the offset of the memory-mapped I/O (MMIO) register that needs to be accessed. An I/O Read returns the current value of this register. An 8/16-bit I/O write to this register is completed by the GMCH but does not update this register. This mechanism to access internal graphics MMIO registers must not be used to access VGA I/O registers that are mapped through the MMIO space. VGA registers must be accessed directly through the dedicated VGA IO ports. Bit Access & Default R/W 00000000 h Description 31:2 1:0 Register Offset: This field selects any one of the DWord registers within the MMIO register space of Device 2. Reserved 10.2.2 MMIO_DATA—MMIO Data Register I/O Address: Size: IOBAR + 4h 32 bits MMIO_DATA: A 32 bit I/O write to this port is re-directed to the MMIO register pointed to by the MMIO-index register. A 32 bit I/O read to this port is re-directed to the MMIO register pointed to by the MMIO-index register. 8 or 16 bit I/O writes are completed by the GMCH and may have un-intended side effects; hence, they must not be used to access the data port. 8 or 16 bit I/O reads are completed normally. Bit Access & Default R/W 00000000 h MMIO Data Window Description 31:0 § 204 Datasheet System Address Map R 11 System Address Map The (G)MCH supports 4 GB of addressable memory space (see Figure 11-1) and 64 KB+3 bytes of addressable I/O space. A programmable memory address space under the 1-MB region is divided into regions that can be individually controlled with programmable attributes such as disable, read/write, write only, or read only. This section focuses on how the memory space is partitioned and what the separate memory regions are used for. I/O address space has simpler mapping and is explained near the end of this section. Note: Address mapping information for the Integrated Graphics Device applies to the 82915G/82915GV/82915GL/82910GL GMCH only. The 82915P/82915PL MCH does not have an IGD. Note: Address mapping information for the PCI Express Device applies to the 82915G/82915P/82915PL (G)MCH only. The 82915GV/82915GL/82910GL GMCH does not support PCI Express. Addressing of memory ranges larger than 4 GB is not supported. The HREQ[4:3] FSB pins are decoded to determine whether the access is above or below 4 GB. The (G)MCH does not support the PCI Dual Address Cycle (DAC) Mechanism, PCI Express 64-bit prefetchable memory transactions, or any other addressing mechanism that allows addressing of greater than 4 GB on either the DMI or PCI Express interface. The (G)MCH does not limit system memory space in hardware. There is no hardware lock to stop someone from inserting more memory than is addressable. In the following sections, it is assumed that all of the compatibility memory ranges reside on the DMI. The exception to this rule is VGA ranges that may be mapped to PCI Express, DMI, or to the internal graphics device (IGD). In the absence of more specific references, cycle descriptions referencing PCI should be interpreted as the DMI/PCI, while cycle descriptions referencing PCI Express or IGD are related to the PCI Express bus or the internal graphics device respectively. The (G)MCH does not remap APIC or any other memory spaces above TOLUD (Top of Low Usable DRAM). The TOLUD register is set to the appropriate value by BIOS. The Address Map includes a number of programmable ranges: • Device 0 ⎯ EPBAR – Egress port registers. Necessary for setting up VC1 as an isochronous channel using time based weighted round robin arbitration. (4-KB window) ⎯ MCHBAR – Memory mapped range for internal (G)MCH registers. For example, memory buffer register controls. (16-KB window) ⎯ PCIEXBAR – Flat memory-mapped address space to access device configuration registers. This mechanism can be used to access PCI configuration space (0h–FFh) and Extended configuration space (100h–FFFh) for PCI Express devices. This enhanced configuration access mechanism is defined in the PCI Express specification. (256-MB window) ⎯ DMIBAR –This window is used to access registers associated with the (G)MCH/ICH6 (DMI) register memory range. (4-KB window) Datasheet 205 System Address Map R ⎯ IFPBAR – Any write to this window will trigger a flush of the (G)MCH’s Global Write Buffer to let software guarantee coherency between writes from an isochronous agent and writes from the processor (4-KB window). ⎯ GGC – 82915G/82915GV/82910GL GMCH graphics control register. Used to select the amount of main memory that is pre-allocated to support the internal graphics device in VGA (non-linear) and Native (linear) modes (0–64-MB options). • Device 1: Function 0: ⎯ MBASE1/MLIMIT1 – PCI Express port non-prefetchable memory access window. ⎯ PMBASE1/PMLIMIT1 – PCI Express port prefetchable memory access window. ⎯ IOBASE1/IOLIMIT1 – PCI Express port I/O access window. • Device 2: Function 0 (82915G/82915GV/82915GL/82910GL GMCH only) ⎯ MMADR – IGD registers and internal graphics instruction port. (512-KB window) ⎯ IOBAR – I/O access window for the GMCH internal graphics. Through this window address/data register pair, using I/O semantics, the IGD and internal graphics instruction port registers can be accessed. Note, this allows accessing the same registers as MMADR. In addition, the IOBAR can be used to issue writes to the GTTADR table. ⎯ GMADR – Internal graphics translation window. (256-MB window) ⎯ GTTADR – Internal graphics translation table location. (256-KB window). Note that the PGTBL_CTL register (MMIO 2020) indicates the physical address base which is 4 KB aligned. • Device 2: Function 1 (82915G/82915GV/82915GL/82910GL GMCH only) ⎯ MMADR – Function 1 IGD registers and internal graphics instruction port. (512-KB window) The rules for the above programmable ranges are: • ALL of these ranges MUST be unique and NON-OVERLAPPING. It is the BIOS or system designer’s responsibility to limit memory population so that adequate PCI, PCI Express, High BIOS, PCI Express Memory Mapped space, and APIC memory space can be allocated. • In the case of overlapping ranges with memory, the memory decode will be given priority. • There are NO Hardware Interlocks to prevent problems in the case of overlapping ranges. • Accesses to overlapped ranges may produce indeterminate results. • The only peer-to-peer cycles allowed below the top of memory (register TOLUD) are DMI to PCI Express VGA range writes. Note that peer to peer cycles to the Internal Graphics VGA range are not supported. Figure 11-1 shows the system memory address map in a simplified form. 206 Datasheet System Address Map R Figure 11-1. System Address Ranges 4 GB PCI Memory Address Range (Subtractively decoded to DMI) Device 0 Bars (EPBAR, MCHBAR, PCIEXBAR, DMIBAR) Device 1 Bars (MBASE1/ MLIMIT1, PMBASE1/ PMLIMIT1) Device 2 1 Bars (MMADR, GMADR, GTTADR) TOLUD Device 0 GGC (Graphics Stolen Memory) Main Memory Address Range Independently Programmable Non-Overlapping Windows 1 MB Legacy Address Range 0 NOTES: 1. Device 2 is not on the 82915P/82915PL MCH. 2. Device 1 is not on the 82915GV/82910GL/82915GL GMCH. 11.1 Legacy Address Range This area is divided into the following address regions: • 0 – 640 KB: DOS Area • 640 – 768 KB: Legacy Video Buffer Area • 768 – 896 KB in 16-KB sections (total of 8 sections): Expansion Area • 896 – 960 KB in 16-KB sections (total of 4 sections): Extended System BIOS Area • 960-KB – 1-MB Memory: System BIOS Area Datasheet 207 System Address Map R Figure 11-2. Microsoft MS-DOS* Legacy Address Range 000F_FFFFh 000F_0000h 000E_FFFFh 000E_0000h 000D_FFFFh Expansion Area 128KB (16KBx8) 000C_0000h 000B_FFFFh Legacy Video Area (SMM Memory) 128KB 000A_0000h 0009_FFFFh 640KB 768KB System BIOS (Upper) 64KB Extended System BIOS (Lower) 64KB (16KBx4) 1MB 960KB 896KB DOS Area 0000_0000h 11.1.1 DOS Range (0h – 9_FFFFh) The DOS area is 640 KB (0000_0000h – 0009_FFFFh) in size and is always mapped to the main memory controlled by the (G)MCH. 11.1.2 Legacy Video Area (A_0000h–B_FFFFh) The legacy 128-KB VGA memory range, frame buffer, (000A_0000h – 000B_FFFFh) can be mapped to IGD, to PCI Express, and/or to the DMI. The appropriate mapping is programmable. Based on the programming, priority for VGA mapping is constant. The (G)MCH always decodes internally mapped devices first. Internal to the 82915G/82915GV/82915GL/82910GL GMCH, decode precedence is always given to the IGD. The (G)MCH always positively decodes internally mapped devices, namely the IGD (82915G/82915GV/82915GL/82910GL only) and PCI Express. Subsequent decoding of regions mapped to PCI Express or the DMI depends on the programming. This region is also the default for SMM space. 208 Datasheet System Address Map R Compatible SMRAM Address Range (A_0000h–B_FFFFh) When compatible SMM space is enabled, SMM-mode processor accesses to this range are routed to physical system DRAM at 000A 0000h–000B FFFFh. Non-SMM-mode processor accesses to this range are considered to be to the Video Buffer Area as described above. PCI Express and DMI originated cycles to enabled SMM space are not allowed and are considered to be to the Video Buffer Area if IGD (82915G/82915GV/82915GL/82910GL GMCH only) is not enabled as the VGA device. PCI Express and DMI initiated cycles are attempted as peer cycles, and will master abort on PCI if no external VGA device claims them. Monochrome Adapter (MDA) Range (B_0000h–B_7FFFh) Legacy support requires the ability to have a second graphics controller (monochrome) in the system. Accesses in the standard VGA range are forwarded to IGD, PCI Express, or the DMI (depending on the programming of the on-chip registers). Since the monochrome adapter may be mapped to any one of these devices, the (G)MCH must decode cycles in the MDA range (000B_0000h – 000B_7FFFh) and forward either to IGD, PCI Express, or the DMI. In addition to the memory range B0000h to B7FFFh, the (G)MCH decodes I/O cycles at 3B4h, 3B5h, 3B8h, 3B9h, 3BAh and 3BFh and forwards them to the either IGD, PCI Express, and/or the DMI. 11.1.3 Expansion Area (C_0000h–D_FFFFh) This 128-KB ISA Expansion region (000C_0000h – 000D_FFFFh) is divided into eight, 16-KB segments. Each segment can be assigned one of four read/write states: read only, write only, read/write, or disabled. Typically, these blocks are mapped through the (G)MCH and are subtractively decoded to ISA space. Memory that is disabled is not remapped. Non-snooped accesses from PCI Express or DMI to this region are always sent to main memory. Table 11-1. Expansion Area Memory Segments Memory Segments 0C0000h–0C3FFFh 0C4000h–0C7FFFh 0C8000h–0CBFFFh 0CC000h –0CFFFFh 0D0000h–0D3FFFh 0D4000h–0D7FFFh 0D8000h–0DBFFFh 0DC000h–0DFFFFh Attributes W/R W/R W/R W/R W/R W/R W/R W/R Comments Add-on BIOS Add-on BIOS Add-on BIOS Add-on BIOS Add-on BIOS Add-on BIOS Add-on BIOS Add-on BIOS Datasheet 209 System Address Map R 11.1.4 Extended System BIOS Area (E_0000h–E_FFFFh) This 64-KB area (000E_0000h – 000E_FFFFh) is divided into four, 16-KB segments. Each segment can be assigned independent read and write attributes so it can be mapped either to main DRAM or to the DMI. Typically, this area is used for RAM or ROM. Memory segments that are disabled are not remapped elsewhere. Non-snooped accesses from PCI Express or DMI to this region are always sent to main memory. Table 11-2. Extended System BIOS Area Memory Segments Memory Segments 0E0000h–0E3FFFh 0E4000h–0E7FFFh 0E8000h–0EBFFFh 0EC000h–0EFFFFh Attributes W/R W/R W/R W/R Comments BIOS Extension BIOS Extension BIOS Extension BIOS Extension 11.1.5 System BIOS Area (F_0000h–F_FFFFh) This area is a single, 64-KB segment (000F_0000h – 000F_FFFFh). This segment can be assigned read and write attributes. It is by default (after reset) read/write disabled and cycles are forwarded to the DMI. By programming the read/write attributes, the (G)MCH can “shadow” BIOS into main memory. When disabled, this segment is not remapped. Non-snooped accesses from PCI Express or DMI to this region are always sent to main memory. Table 11-3. System BIOS Area Memory Segments Memory Segments 0F0000h–0FFFFFh Attributes WE RE Comments BIOS Area 11.1.6 Programmable Attribute Map (PAM) Memory Area Details The 13 sections from 768 KB to 1 MB comprise what is also known as the PAM memory area. The (G)MCH does not handle IWB (Implicit Write-Back) cycles targeting DMI. Since all memory residing on DMI should be set as non-cacheable, there will normally not be IWB cycles targeting DMI. However, DMI becomes the default target for processor and DMI originated accesses to disabled segments of the PAM region. If the MTRRs covering the PAM regions are set to WB or RC, it is possible to get IWB cycles targeting DMI. This may occur for DMI-originated cycles to disabled PAM regions. Warning: For example, assume that a particular PAM region is set for “Read Disabled” and the MTRR associated with this region is set to WB. A DMI master generates a memory read targeting the PAM region. A snoop is generated on the FSB and the result is an IWB. Since the PAM region is “Read Disabled”, the default target for the Memory Read becomes DMI. The IWB associated with this cycle will cause the (G)MCH to hang. 210 Datasheet System Address Map R 11.2 Main Memory Address Range (1 MB to TOLUD) This address range extends from 1 MB to the top of physical memory that is permitted to be accessible by the (G)MCH (as programmed by in the TOLUD register). All accesses to addresses within this range will be forwarded by the (G)MCH to the main memory unless they fall into the optional TSEG, optional ISA Hole, or optional IGD stolen VGA memory. The (G)MCH provides a maximum main memory address decode space of 4 GB. The (G)MCH does not remap APIC or PCI Express memory space. This means that as the amount of physical memory populated in the system reaches 4 GB, there will be physical memory that exists, yet nonaddressable; therefore, this memory is unusable by the system. The (G)MCH does not limit main memory address space in hardware. Figure 11-3. Main Memory Address Range FFFF_FFFFh 4 GB Maximum Flash APIC Contains programmable windows, ICH6/PCI ranges. PCI Memory Range TOLUD IGD (1–32 MB, optional) TSEG (1 MB / 2 MB / 8 MB, optional) Main Memory 0100_000h 00F0_000h ISA Hole (optional) Main Memory 0010_000h DOS Compatibility Memory 0h 0 MB Main_Mem_Addr_G-P_Only 16 MB 15 MB 1 MB 11.2.1 ISA Hole (15 MB–16 MB) BIOS can create a hole at 15 MB–16 MB. Accesses within this hole are forwarded to the DMI. The range of physical main memory disabled by opening the hole is not remapped to the top of the memory; that physical main memory space is not accessible. This 15 MB–16 MB hole is an optionally enabled ISA hole. Datasheet 211 System Address Map R 11.2.2 TSEG TSEG is optionally 1 MB, 2 MB, or 8 MB in size. TSEG is below IGD stolen memory, which is at the top of physical memory. SMM-mode processor accesses to enabled TSEG access the physical DRAM at the same address. Non-processor originated accesses are not allowed to SMM space. PCI Express, DMI, and Internal Graphics originated cycles to enabled SMM space are handled as invalid cycle type with reads and writes to location 0 and byte enables turned off for writes. When the extended SMRAM space is enabled, processor accesses to the TSEG range without SMM attribute or without WB attribute are also forwarded to memory as invalid accesses. Non-SMM-mode write-back cycles that target TSEG space are completed to main memory for cache coherency. When SMM is enabled, the maximum amount of memory available to the system is equal to the amount of physical main memory minus the value in the TSEG register which is fixed at 1 MB, 2 MB or 8 MB. 11.2.3 Pre-allocated Memory Voids of physical addresses that are not accessible as general system memory and reside within system memory address range (< TOLUD) are created for SMM-mode and legacy VGA graphics compatibility. It is the responsibility of BIOS to properly initialize these regions. Table 11-4 details the location and attributes of the regions. Table 11-4. Pre-Allocated Memory Example for 64-MB DRAM, 1-MB VGA and 1-MB TSEG Memory Segments 0000_0000h – 03DF_FFFFh 03E0_0000h – 03EF_FFFFh 03F0_0000h – 03FF_FFFFh Attributes R/W SMM Mode Only processor reads R/W Comments Available system memory 62 MB TSEG Address Range and Pre-allocated memory Pre-allocated Graphics VGA memory. 1 MB (or 4/8/16/32/64 MB) when IGD is enabled. 11.3 PCI Memory Address Range (TOLUD – 4 GB) This address range, from the top of physical memory to 4 GB (top of addressable memory space supported by the (G)MCH) is normally mapped via the DMI to PCI. Exceptions to this mapping include BAR memory mapped regions that include: • EPBAR, MCHBAR, DMIBAR. • The second exception to the mapping rule deals with the PCI Express port: ⎯ Addresses decoded to the PCI Express Memory Window defined by the MBASE1, MLIMIT1, PMBASE1, and PMLIMIT1 registers are mapped to PCI Express. ⎯ Addresses decoded to PCI Express configuration space are mapped based on Bus, Device, and Function number. (PCIEXBAR range). • The third exception to the mapping rule occurs in an internal graphics configuration (82915G GMCH only): ⎯ Addresses decoded to the Graphics Memory Range. (GMADR range) ⎯ Addresses decoded to the Graphics Translation Table range (GTTADR range). 212 Datasheet System Address Map R ⎯ Addresses decoded to the Memory Mapped Range of the Internal Graphics Device (MMADR range). There is a MMADR range for device 2 function 0 and a MMADR range for device 2 function 1. Both ranges are forwarded to the Internal Graphics Device. The exceptions listed above for internal graphics and the PCI Express ports MUST NOT overlap with APCI Configuration, FSB Interrupt Space and High BIOS Address Range. Figure 11-4. PCI Memory Address Range FFFF_FFFFh High BIOS FFE0_0000h DMI Interface (subtractively decode) FEF0_0000h FEE0_0000h FED0_0000h FEC8_0000h FEC0_0000h DMI Interface (subtractively decode) F000_0000h PCI Express Configuration Space E000_0000h 4 GB – 512 MB DMI Interface (subtractively decode) Programmable windows, graphics ranges, PCI Express* Port could be here TOLUD PCI_Address_Ranges_G-P-only 4 GB 4 GB – 2 MB 4 GB – 17 MB FSB Interrupts DMI Interface (subtractively decode) Local (processor) APIC I/O APIC 4 GB – 20 MB 4 GB – 18 MB 4 GB – 19 MB Optional HSEG FEDA_0000h to FEDB_FFFFh 4 GB – 256 MB Possible address range (Not guaranteed) Datasheet 213 System Address Map R 11.3.1 APIC Configuration Space (FEC0_0000h-FECF_FFFFh) This range is reserved for APIC configuration space. The I/O APIC(s) usually reside in the ICH6 portion of the chipset, but may also exist as stand-alone components. The IOAPIC spaces are used to communicate with IOAPIC interrupt controllers that may be populated in the system. Since it is difficult to relocate an interrupt controller using plug-and-play software, fixed address decode regions have been allocated for them. Processor accesses to the default IOAPIC region (FEC0_0000h to FEC7_FFFFh) are always forwarded to DMI. 11.3.2 HSEG (FEDA_0000h–FEDB_FFFFh) This optional segment from FEDA_0000h to FEDB_FFFFh provides a remapping window to SMM memory. It is sometimes called the High SMM memory space. SMM-mode processor accesses to the optionally enabled HSEG are remapped to 000A_0000h – 000B_FFFFh. NonSMM-mode processor accesses to enabled HSEG are considered invalid and are terminated immediately on the FSB. The exceptions to this rule are Non-SMM-mode write-back cycles that are remapped to SMM space to maintain cache coherency. PCI Express and DMI originated cycles to enabled SMM space are not allowed. Physical main memory behind the HSEG transaction address is not remapped and is not accessible. All cacheline writes with WB attribute or Implicit write backs to the HSEG range are completed to DRAM like an SMM cycle. 11.3.3 FSB Interrupt Memory Space (FEE0_0000–FEEF_FFFF) The FSB Interrupt space is the address used to deliver interrupts to the FSB. Any device on PCI Express or DMI may issue a memory write to 0FEEx_xxxxh. The (G)MCH will forward this memory write along with the data to the FSB as an Interrupt Message Transaction. The (G)MCH terminates the FSB transaction by providing the response and asserting HTRDY#. This memory write cycle does not go to DRAM. 11.3.4 High BIOS Area The top 2 MB (FFE0_0000h -FFFF_FFFFh) of the PCI memory address range is reserved for system BIOS (High BIOS), extended BIOS for PCI devices, and the A20 alias of the system BIOS. The processor begins execution from the High BIOS after reset. This region is mapped to the DMI so that the upper subset of this region aliases to the 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; thus, that full 2 MB must be considered. 214 Datasheet System Address Map R 11.3.5 PCI Express* Configuration Address Space (Intel® 82915G/82915P Only) A configuration register defines the base address for the 256-MB block of addresses below top of addressable memory (4 GB) for the configuration space associated with all devices and functions that are potentially a part of the PCI Express root complex hierarchy. This range will be aligned to a 256-MB boundary. BIOS must assign this address range such that it will not conflict with any other address ranges. 11.3.6 PCI Express* Graphics Attach (Intel® 82915G/82915P Only) The (G)MCH can be programmed to direct memory accesses to the PCI Express interface when addresses are within either of two programmed ranges specified via registers in the (G)MCH’s Device 1 configuration space. • The first range is controlled via the Memory Base Register (MBASE) and Memory Limit Register (MLIMIT) registers. • The second range is controlled via the Prefetchable Memory Base (PMBASE) and Prefetchable Memory Limit (PMLIMIT) registers. The (G)MCH positively decodes memory accesses to PCI Express memory address space as defined by the following equations: Memory_Base_Address ≤ Address ≤ Memory_Limit_Address Prefetchable_Memory_Base_Address ≤ Address ≤ Prefetchable_Memory_Limit_Address It is essential to support a separate Prefetchable range to apply USWC attribute (from the processor point of view) to that range. The USWC attribute is used by the processor for write combining. Note: The programmable ranges are used to allocate memory address space for any PCI Express devices sitting on PCI Express that require such a window. The PCICMD1 register can override the routing of memory accesses to PCI Express. In other words, the memory access enable bit must be set in the device 1 PCICMD1 register to enable the memory base/limit and prefetchable base/limit windows. 11.3.7 AGP DRAM Graphics Aperture Unlike AGP4x, PCI Express has no concept of aperture for PCI Express devices. As a result, there is no need to translate addresses from PCI Express. Therefore, the (G)MCH has no APBASE and APSIZE registers. Datasheet 215 System Address Map R 11.3.8 Graphics Memory Address Ranges (Intel® 82915G/82915GV/82915GL/82910GL GMCH Only) The GMCH can be programmed to direct memory accesses to IGD when addresses are within any of three programmable ranges. • The Memory Map Base Register (MMADR) is used to access graphics control registers. • The Graphics Memory Aperture Base Register (GMADR) is used to access graphics memory allocated via the graphics translation table. • The Graphics Translation Table Base Register (GTTADR) is used to access the translation table. Normally these ranges will reside above the Top-of-Main-DRAM and below High BIOS and APIC address ranges. They normally reside above the top of memory (TOLUD) so that physical DRAM memory space is not allocate to them. The memory allocated via the graphics translation table is a Prefetchable range to apply USWC attribute (from the processor point of view) to that range. The USWC attribute is used by the processor for write combining. 11.4 System Management Mode (SMM) System Management Mode uses main memory for System Management RAM (SMM RAM). The (G)MCH supports: Compatible SMRAM (C_SMRAM), High Segment (HSEG), and Top of Memory Segment (TSEG). System Management RAM space provides a memory area that is available for the SMI handlers 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. (G)MCH 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 TSEG area of 1 MB, 2 MB, or 8 MB in size. For the 82915G/82915GV/82915GL/82910GL GMCH, the TSEG area lies below IGD stolen memory. The above 1-MB solutions require changes to compatible SMRAM handler’s code to properly execute above 1 MB. Note: DMI and PCI Express masters are not allowed to access the SMM space. 216 Datasheet System Address Map R 11.4.1 SMM Space Definition SMM space is defined by its addressed SMM space and its DRAM SMM space. The addressed SMM space is defined as the range of bus addresses used by the processor to access SMM space. DRAM SMM space is defined as the range of physical DRAM memory locations containing the SMM code. SMM space can be accessed at one of three transaction address ranges: Compatible, High, and TSEG. The Compatible and TSEG SMM space is not remapped; therefore, the addressed and DRAM SMM space is the same address range. Since the High SMM space is remapped, the addressed and DRAM SMM space are different address ranges. Note that the High DRAM space is the same as the Compatible Transaction Address space. The following table describes three unique address ranges: • Compatible Transaction Address • High Transaction Address • TSEG Transaction Address SMM Space Enabled Compatible (C) High (H) TSEG (T) Transaction Address Space 000A_0000h to 000B_FFFFh FEDA_0000h to FEDB_FFFFh (TOLUD-STOLEN-TSEG) to TOLUD-STOLEN DRAM Space (DRAM) 000A_0000h to 000B_FFFFh 000A_0000h to 000B_FFFFh (TOLUD-STOLEN-TSEG) to TOLUD-STOLEN 11.4.2 SMM Space Restrictions If any of the following conditions are violated, the results of SMM accesses are unpredictable and may cause the system to hang: • The Compatible SMM space must not be set-up as cacheable. • High or TSEG SMM transaction address space must not overlap address space assigned to system main memory, or to any “PCI” devices (including DMI, PCI Express, and graphics devices). This is a BIOS responsibility. • Both D_OPEN and D_CLOSE capability must not be enabled at the same time. • When TSEG SMM space is enabled, the TSEG space must not be reported to the OS as available main memory. This is a BIOS responsibility. • Any address translated through the internal graphics device’s TLB must not target main memory from A_0000-F_FFFF. Datasheet 217 System Address Map R 11.4.3 SMM Space Combinations When High SMM is enabled, the Compatible SMM space is effectively disabled. Processor originated accesses to the Compatible SMM space are forwarded to PCI Express if this VGA capability is enabled; otherwise, they are forwarded to the DMI. PCI Express and DMI originated accesses are never allowed to access SMM space. Table 11-5. SMM Space Table Global Enable G_SMRAME 0 1 1 1 1 High Enable H_SMRAM_EN X 0 0 1 1 TSEG Enable TSEG_EN X 0 1 0 1 Compatible (C) Range Disable Enable Enable Disabled Disabled High (H) Range Disable Disable Disable Enable Enable TSEG (T) Range Disable Disable Enable Disable Enable 11.4.4 SMM Control Combinations The G_SMRAME bit provides a global enable for all SMM memory. The D_OPEN bit allows software to write to the SMM ranges without being in SMM mode. BIOS software can use this bit to initialize SMM code at powerup. The D_LCK bit limits the SMM range access to only SMM mode accesses. The D_CLS bit causes SMM data accesses to be forwarded to the DMI or PCI Express. The SMM software can use this bit to write to video memory while running SMM code out of DRAM. Table 11-6. SMM Control Table G_SMRAME 0 1 1 1 1 1 1 1 1 D_LCK x 0 0 0 0 0 1 1 1 D_CLS X X 0 0 1 1 X 0 1 D_OPEN x 0 0 1 0 1 x x x Processor in SMM Mode x 0 1 x 1 x 0 1 1 SMM Code Access Disable Disable Enable Enable Enable Invalid Disable Enable Enable SMM Data Access Disable Disable Enable Enable Disable Invalid Disable Enable Disable 218 Datasheet System Address Map R 11.4.5 SMM Space Decode and Transaction Handling Only the processor is allowed to access SMM space. PCI Express and DMI originated transactions are not allowed to SMM space. 11.4.6 Processor WB Transaction to an Enabled SMM Address Space Processor write-back transactions (HREQ1# = 0) to enabled SMM address space must be written to the associated SMM DRAM, even though the space is not open and the transaction is not performed in SMM mode. This ensures SMM space cache coherency when cacheable extended SMM space is used. 11.4.7 SMM Access through GTT TLB (Intel® 82915G/82915GV/82910GL GMCH Only) Accesses through GTT TLB address translation to enabled SMM DRAM space are not allowed. Writes will be routed to memory address 0h with byte enables de-asserted and reads will be routed to memory address 0h. If a GTT TLB translated address hits enabled SMM DRAM space, an Invalid Translation Table Entry Flag is reported to BIOS. PCI Express and DMI originated accesses are never allowed to access SMM space directly or through the GTT TLB address translation. If a GTT TLB translated address hits enabled SMM DRAM space, an Invalid Translation Table Entry Flag is reported to BIOS. PCI Express and DMI write accesses through graphics memory range set up by BIOS will be snooped. If, when translated, the resulting physical address is to enabled SMM DRAM space, the request will be remapped to address 0h with de-asserted byte enables. PCI Express and DMI read accesses to the graphics memory range set up by BIOS are not supported; therefore, users/systems will have no address translation concerns. PCI Express and DMI reads to the graphics memory range will be remapped to address 0h. The read will complete with UR (unsupported request) completion status. GTT fetches are always decoded (at fetch time) to ensure they are not in SMM (actually, anything above base of TSEG or 640 KB – 1 MB). Thus, they will be invalid and go to address 0h. This is not specific to PCI Express or DMI; it applies to the processor or internal graphics engines. Also, since the graphics memory range snoop would not be directly to SMM space, there would not be a writeback to SMM. In fact, the writeback would also be invalid (because it uses the same translation) and goes to address 0h. 11.4.8 Memory Shadowing Any block of memory that can be designated as “read only” or “write only” can be “shadowed” into (G)MCH main memory. Typically, this is done to allow ROM code to execute more rapidly out of main DRAM memory. ROM is used as 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. Datasheet 219 System Address Map R 11.4.9 I/O Address Space The (G)MCH does not support the existence of any other I/O devices beside itself on the processor bus. The (G)MCH generates either DMI or PCI Express bus cycles for all processor I/O accesses that it does not claim. Within the host bridge, the (G)MCH contains two internal registers in the processor I/O space. These locations are used to implement a configuration space access mechanism. The processor allows 64 KB+3 bytes to be addressed within the I/O space. The (G)MCH propagates the processor I/O address without any translation on to the destination bus; therefore, providing addressability for 64 KB+3 byte locations. Note that the upper 3 locations can be accessed only during I/O address wrap-around when processor bus HA16# address signal is asserted. HA16# is asserted on the processor bus when an I/O access is made to 4 bytes from address 0FFFDh, 0FFFEh, or 0FFFFh. HA16# is also asserted when an I/O access is made to 2 bytes from address 0FFFFh. For the 828915G GMCH, a set of I/O accesses (other than ones used for configuration space access) are consumed by the internal graphics device if it is enabled. The mechanisms for internal graphics I/O decode and the associated control are explained later. The I/O accesses (other than ones used for configuration space access) are forwarded normally to the DMI bus unless they fall within the PCI Express I/O address range as defined by the mechanisms explained below. I/O writes are not posted. Memory writes to the ICH6 or PCI Express are posted. The (G)MCH responds to I/O cycles initiated on PCI Express or DMI with a UR status. Upstream I/O cycles and configuration cycles should never occur. If one does occur, the request will route as a read to memory address 0h so a completion is naturally generated (whether the original request was a read or write). The transaction will complete with a UR completion status. 11.4.10 PCI Express* I/O Address Mapping (Intel® 82915G/82915P/82915PL Only) The (G)MCH can be programmed to direct non-memory (I/O) accesses to the PCI Express bus interface when processor-initiated I/O cycle addresses are within the PCI Express I/O address range. 11.4.11 (G)MCH Decode Rules and Cross-Bridge Address Mapping The following are (G)MCH decode rules and cross-bridge address mapping used in this chipset: • VGAA = 000A_0000h – 000A_FFFFh • MDA = 000B_0000h – 000B_7FFFh • VGAB = 000B_8000h – 000B_FFFFh • MAINMEM = 0100_0000 to TOLUD 220 Datasheet System Address Map R 11.4.12 Legacy VGA and I/O Range Decode Rules The legacy 128-KB VGA memory range 000A_0000h-000B_FFFFh can be mapped to IGD (82915G/82915GV/82915GL/82910GL GMCH only), to PCI Express (Device #1), and/or to the DMI depending on BIOS programming. Priority for VGA mapping is constant in that the (G)MCH always decodes internally mapped devices first. Internal to the GMCH, decode precedence is always given to IGD. The (G)MCH always positively decodes internally mapped devices, namely the IGD and PCI Express. § Datasheet 221 System Address Map R 222 Datasheet Functional Description R 12 12.1 Functional Description This chapter describes the (G)MCH interfaces and major functional units. Host Interface The (G)MCH supports the Pentium 4 processor subset of the Enhanced Mode Scaleable Bus. The cache line size is 64 bytes. Source synchronous transfer is used for the address and data signals. The address signals are double pumped, and a new address can be generated every other bus clock. At 133/200 MHz bus clock, the address signals run at 266/400 MT/s for a maximum address queue rate of 66/100 million addresses/sec. The data is quad pumped and an entire 64 byte cache line can be transferred in two bus clocks. At 133/200 MHz bus clock the data signals run at 533/800 MT/s for a maximum bandwidth of 4.2 GB/s or 6.4 GB/s. Note: The host interface on the 82910GL GMCH runs at 133 MHz only. The FSB interface supports up to 12 simultaneous outstanding transactions. The (G)MCH supports only one outstanding deferred transaction on the FSB. 12.1.1 FSB GTL+ Termination The (G)MCH integrates GTL+ termination resistors on die. Also, approximately 2.8 pf (fast) – 3.3 pf (slow) per pad of on die capacitance will be implemented to provide better FSB electrical performance. 12.1.2 FSB Dynamic Bus Inversion The (G)MCH supports Dynamic Bus Inversion (DBI) when driving and when receiving data from the processor. DBI limits the number of data signals that are driven to a low voltage on each quad pumped data phase. This decreases the worst-case power consumption of the (G)MCH. HDINV[3:0]# indicate if the corresponding 16 bits of data are inverted on the bus for each quad pumped data phase: HDINV[3:0]# HDINV0# HDINV1# HDINV2# HDINV3# Data Bits HD[15:0] HD[31:16] HD[47:32] HD[63:48] When the processor or the (G)MCH drives data, each 16-bit segment is analyzed. If more than 8 of the 16 signals would normally be driven low on the bus, the corresponding HDINVx# signal will be asserted and the data will be inverted prior to being driven on the bus. When the processor or the (G)MCH receives data, it monitors HDINV[3:0]# to determine if the corresponding data segment should be inverted. Datasheet 223 Functional Description R 12.1.3 APIC Cluster Mode Support This is required for backwards compatibility with existing software, including various operating systems. As one example, beginning with Microsoft Windows 2000 there is a mode (boot.ini) that allows an end user to enable the use of cluster addressing support of the APIC. The (G)MCH supports three types of interrupt re-direction: • Physical • Flat-Logical • Clustered-Logical 12.2 System Memory Controller This section describes the (G)MCH system memory interface for both DDR memory and DDR2 memory. The (G)MCH supports both DDR and DDR2 memory and either one or two DIMMs per channel. Note: The 82915G/82915GV GMCH and 82915P MCH support both DDR memory and DDR2 memory, and either one or two DIMMs per channel. The 82910GL only supports DDR memory and a maximum of one DIMM per channel. The 82915PL and 82915GL support only DDR and either one or two DIMMs per channel. 12.2.1 Memory Organization Modes The system memory controller supports two styles of memory organization (Interleaved and Asymmetric) and two modes of operation (DDR and DDR2). Rules for populating DIMM slots are included in this chapter. Interleaved Mode This mode provides maximum performance on real applications. Addresses are ping-ponged between the channels, and the switch happens after each cache line (64 byte boundary). If two consecutive cache lines are requested, both may be retrieved simultaneously, since they are guaranteed to be on opposite channels. The drawbacks of Interleaved Mode are that the system designer must populate both channels of memory such that they have equal capacity, but the technology and device width may vary from one channel to the other. Refer to Figure 12-1 for further clarification. Asymmetric Mode This mode trades performance for system design flexibility. Unlike the previous mode, addresses start in channel A and stay there until the end of the highest rank in channel A; then, addresses continue from the bottom of channel B to the top. Real world applications are unlikely to make requests that alternate between addresses that sit on opposite channels with this memory organization, so in most cases, bandwidth will be limited to that of a single channel. The system designer is free to populate or not to populate any rank on either channel, including either degenerate single channel case. Refer to Figure 12-1 for further clarification. 224 Datasheet Functional Description R Figure 12-1. System Memory Styles Dual Channel Interleaved (channels do not have to match) CL TOM CH B CH A TOM CH B CH B0 CH A TOM CH A or CH B CH B CH A CH B CH A 0 Scheme XOR Bit 6 => CL Sys_Mem_Styles Single Channel Dual Channel Asymmetric (channels do not have to match) CL CL CH B TOM CH A CH A0 0 Table 12-1. Sample System Memory Organization with Interleaved Channels Rank Channel A population 0 MB 256 MB 512 MB 512 MB Cumulative top address in Channel A 2560 MB 2560 MB 2048 MB 1024 MB Channel B population 0 MB 256 MB 512 MB 512 MB Cumulative top address in Channel B 2560 MB 2560 MB 2048 MB 1024 MB 3 2 1 0 Table 12-2. Sample System Memory Organization with Asymmetric Channels Rank Channel A population 0 MB 256 MB 512 MB 512 MB Cumulative top address in Channel A 1280 MB 1280 MB 1024 MB 512 MB Channel B population 0 MB 256 MB 512 MB 512 MB Cumulative top address in Channel B 2560 MB 2560 MB 2304 MB 1792 MB 3 2 1 0 Datasheet 225 Functional Description R 12.3 System Memory Configuration Registers Overview The configuration registers located in the PCI configuration space of the (G)MCH control the system memory operation. Following is a brief description of configuration registers. • DRAM Rank Boundary (CxDRBy): The x represents a channel, either A (where x = 0) or B (where x = 1). The y represents a rank, 0 through 3. DRB registers define the upper addresses for a rank of DRAM devices in a channel. When the (G)MCH is configured in asymmetric mode, each register represents a single rank. When the (G)MCH is configured in a dual interleaved mode, each register represents a pair of corresponding ranks in opposing channels. There are 4 DRB registers for each channel. • DRAM Rank Architecture (CxDRAy): The x represents a channel, either A (where x = 0) or B (where x = 1). The y represents a rank, 0 through 3. DRA registers specify the architecture features of each rank of devices in a channel. The only architecture feature specified is page size. When the (G)MCH is configured in asymmetric mode, each DRA represents a single rank in a single channel. When the (G)MCH is configured in a dualchannel lock-step or interleaved mode, each DRA represents a pair of corresponding ranks in opposing channels. There are 4 DRA registers per channel. Each requires only 3 bits, so there are two DRAs packed into a byte. • Clock Configuration (CLKCFG): Specifies DRAM frequency. The same clock frequency will be driven to all DIMMs. • DRAM Timing (CxDRTy): The x represents a channel, A (where x = 0) or B (where x = 1). A second register for a channel is differentiated by y, A or B. The DRT registers define the timing parameters for all devices in a channel. The BIOS programs this register with “least common denominator” values after reading the SPD registers of each DIMM in the channel. • DRAM Control (CxDRCy): The x represents a channel, A (where x = 0) or B (where x = 1). A second register for a channel is differentiated by y, A or B. DRAM refresh mode, rate, and other controls are selected here. 226 Datasheet Functional Description R 12.3.1 DRAM Technologies and Organization All standard 256-Mb, 512-Mb, and 1-Gb technologies and addressing are supported for x16 and x8 devices. • All supported DDR devices have 4 banks; all supported DDR2 devices have 4 or 8 banks. • The (G)MCH supports various page sizes. Page size is individually selected for every rank. • 4 KB, 8 KB, and 16 KB for asymmetric, interleaved, or single-channel modes. • The DRAM sub-system supports single or dual channels, 64-b wide per channel. • There can be a maximum of four ranks populated (two double-sided DIMMs) per channel. • Mixed mode double-sided DIMMs (x8 and x16 on the same DIMM) are not supported • By using 1-Gb technology, the largest memory capacity is 8 GB 32M rows/bank * 4 banks/device * 8 columns * 8 devices/rank * 4 ranks/channel * 2 channel * 1b/(row*column) * 1G/1024M * 1B/8b = 8 GB. Though it is possible to put 8 GB in system by stuffing both channels this way, the (G)MCH is still limited to 4 GB of addressable space due to the number of address pins on the FSB. • By using 256-Mb technology, the smallest memory capacity is 128 MB (4M rows/bank * 4banks/device * 16 columns * 4 devices/rank * 1 rank * 1B/8b =128 MB) 12.3.1.1 Rules for Populating DIMM Slots • In all modes, the frequency of system memory will be the lowest frequency of all DIMMs in the system, as determined through the SPD registers on the DIMMs. • In the Single Channel mode, any DIMM slot within the channel may be populated in any order. Either channel may be used. To save power, do not populate the unused channel. • In Dual-Channel Asymmetric mode, any DIMM slot may be populated in any order. • In Dual-Channel Interleaved mode, any DIMM slot may be populated in any order, but the total memory in each channel must be the same. Datasheet 227 Functional Description R 12.3.1.2 System Memory Supported Configurations The (G)MCH supports the 256-Mbit, 512-Mbit and 1-Gbit technology based DIMMs from Table 12-3. Table 12-3. DDR / DDR2 DIMM Supported Configurations Technology Configuration # of Row Address Bits 13 13 13 13 14 14 14 13 14 # of Column Address Bits # of Bank Address Bits Page Size Rank Size 256Mbit 256Mbit 512Mbit 512Mbit 512Mbit 1Gbit 1Gbit 1Gbit 1Gbit 16M X 16 32M X 8 32M X 16 64M X 8 64M X 8 64M X 16 128M X 8 64M X 16 128M X 8 9 10 10 11 10 10 11 10 10 2 2 2 2 2 2 2 3 3 4K 8K 8K 16K 8K 8K 16K 8K 8K 128 MB 256 MB 256 MB 512 MB 512 MB 512 MB 1 GB 512 MB 1 GB 12.3.1.3 Main Memory DRAM Address Translation and Decoding Table 12-4 and Table 12-5 specify the host interface to memory interface address multiplex for the (G)MCH. Refer to the details of the various DIMM configurations as described in Table 12-3. The address lines specified in the column header refer to the host (processor) address lines. 228 Datasheet Functional Description R Table 12-4. DRAM Address Translation (Single Channel/Dual Asymmetric Mode) Rank Size Page Size Banks Tech 31 30 29 28 27 26 r10 25 r9 r9 r9 r9 r9 r9 r9 r9 r9 r9 24 r8 r8 r8 r8 r8 r8 r8 r8 r8 r8 23 r7 r7 r7 r7 r7 r7 r7 r7 r7 r7 22 r6 r6 r6 r6 r6 r6 r6 r6 r6 r6 21 r5 r5 r5 r5 r5 r5 r5 r5 r5 r5 20 r4 r4 r4 r4 r4 r4 r4 r4 r4 r4 19 r3 r3 r3 r3 r3 r3 r3 r3 r3 r3 18 r2 r2 r2 r2 r2 r2 r2 r2 r2 r2 17 r1 r1 r1 r1 r1 r1 r1 r1 r1 r1 16 r0 r0 r0 r0 r0 r0 r0 r0 r0 r0 15 r11 r11 r11 b0 r11 r11 r11 b0 b0 b0 14 r12 b1 b1 b1 b1 b1 b1 b1 b1 b1 13 b0 b0 b0 12 b1 c9 c9 11 c8 c8 c8 c8 c8 c8 c8 c8 c8 c8 10 c7 c7 c7 c7 c7 c7 c7 c7 c7 c7 9 c6 c6 c6 c6 c6 c6 c6 c6 c6 c6 8 c5 c5 c5 c5 c5 c5 c5 c5 c5 c5 7 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 6 c3 c3 c3 c3 c3 c3 c3 c3 c3 c3 5 c2 c2 c2 c2 c2 c2 c2 c2 c2 c2 4 c1 c1 c1 c1 c1 c1 c1 c1 c1 c1 3 c0 c0 c0 c0 c0 c0 c0 c0 c0 c0 256 Mb x16 4i 256 Mb x8 4i 4 KB 8 KB 8 KB 16 KB 8 KB 8 KB 8 KB 16 KB 8 KB 8 KB 128 MB 256 MB 256 MB 512 MB 256 MB 512 MB 512 MB 1 GB 512 MB 1 GB r13 r13 r13 r13 r11 r11 r11 r11 r12 r12 r12 r12 r12 r12 r12 r12 r12 r10 r10 r10 r10 r10 r10 r10 r10 r10 512 Mb x16 4i 512 Mb x8 4i c11 c9 b0 b0 b0 c9 c9 c9 512 Mb x16 4i 512 Mb x8 1 Gb x16 1 Gb x8 1 Gb x16 1 Gb x8 4i 4i 4i 8i 8i c11 c9 b2 b2 c9 c9 NOTES: 1. b – ‘bank’ select bit 2. c – ‘column’ address bit 3. r – ‘row’ address bit Datasheet 229 Functional Description R Table 12-5. DRAM Address Translation (Dual Channel Symmetric Mode) Rank Size Page Size Banks Tech 31 30 29 28 27 r10 26 r9 r9 r9 r9 r9 r9 r9 r9 r9 r9 25 r8 r8 r8 r8 r8 r8 r8 r8 r8 r8 24 r7 r7 r7 r7 r7 r7 r7 r7 r7 r7 23 r6 r6 r6 r6 r6 r6 r6 r6 r6 r6 22 r5 r5 r5 r5 r5 r5 r5 r5 r5 r5 21 r4 r4 r4 r4 r4 r4 r4 r4 r4 r4 20 r3 r3 r3 r3 r3 r3 r3 r3 r3 r3 19 r2 r2 r2 r2 r2 r2 r2 r2 r2 r2 18 r1 r1 r1 r1 r1 r1 r1 r1 r1 r1 17 r0 r0 r0 r0 r0 r0 r0 r0 r0 r0 16 r11 r11 r11 b0 r11 r11 r11 b0 b0 b0 15 r12 b1 b1 b1 b1 b1 b1 b1 b1 b1 14 b0 b0 b0 13 b1 c9 c9 12 c8 c8 c8 c8 c8 c8 c8 c8 c8 c8 11 c7 c7 c7 c7 c7 c7 c7 c7 c7 c7 10 c6 c6 c6 c6 c6 c6 c6 c6 c6 c6 9 c5 c5 c5 c5 c5 c5 c5 c5 c5 c5 8 c4 c4 c4 c4 c4 c4 c4 c4 c4 c4 7 c3 c3 c3 c3 c3 c3 c3 c3 c3 c3 6 h h h h h h h h h h 5 c2 c2 c2 c2 c2 c2 c2 c2 c2 c2 4 c1 c1 c1 c1 c1 c1 c1 c1 c1 c1 3 c0 c0 c0 c0 c0 c0 c0 c0 c0 c0 256 Mb x16 4i 256 Mb x8 4i 4 KB 8 KB 8 KB 16 KB 4 KB 8 KB 8 KB 16 KB 4 KB 8 KB 128 MB 256 MB 256 MB 512 MB 256 MB 512 MB 512 MB 1 GB 512 MB 1 GB r13 r13 r13 r13 r11 r11 r11 r11 r12 r12 r12 r12 r12 r12 r12 r12 r12 r10 r10 r10 r10 r10 r10 r10 r10 r10 512 Mb x16 4i 512 Mb x8 4i c11 c9 b0 b0 b0 c9 c9 c9 512 Mb x16 4i 512 Mb x8 1 Gb x16 1 Gb x8 1 Gb x16 1 Gb x8 4i 4i 4i 8i 8i c11 c9 b2 b2 c9 c9 NOTES: 1. b – ‘bank’ select bit 2. c – ‘column’ address bit 3. h – channel select bit 4. r – ‘row’ address bit 230 Datasheet Functional Description R 12.3.2 DRAM Clock Generation The (G)MCH generates three differential clock pairs for every supported DIMM. There are a total of 6 clock pairs driven directly by the (G)MCH to 2 DIMMs per channel (82915G/82915GV/82915GL and 82915P) and to 1 DIMM per channel (82910GL/82915PL). 12.3.3 Suspend-to-RAM and Resume When entering the Suspend-to-RAM (STR) state, the SDRAM controller will flush pending cycles and then enter all SDRAM rows into self refresh. In STR, the CKE signals remain LOW so the SDRAM devices will perform self-refresh.n 12.3.4 DDR2 On-Die Termination On-die termination (ODT) is a feature that allows a DRAM to turn on/off internal termination resistance for each DQ, DM, DQS, and DQS# signal for x8 and x16 configurations via the ODT control signals. The ODT feature is designed to improve signal integrity of the memory channel by allowing the termination resistance for the DQ, DM, DQS, and DQS# signals to be located inside the DRAM devices themselves, instead of on the motherboard. The (G)MCH drives out the required ODT signals, based on memory configuration and which rank is being written to or read from, to the DRAM devices on a targeted DIMM rank to enable or disable their termination resistance. 12.3.5 DDR2 Off-Chip Driver Impedance Calibration The OCD impedance adjustment mode allows the (G)MCH to measure and adjust the pull-up and pull-down strength of the DRAM devices. It uses a series of EMRS commands to guide the DRAM through measurement and calibration cycles. This feature is described in more detail in the JEDEC DDR2 device specification. The algorithm and sequence of the adjustment cycles is handled by software. The (G)MCH adjusts the DRAM driver impedance by issuing OCD commands to the DIMM and looking at the analog voltage on the DQ lines. Datasheet 231 Functional Description R 12.4 PCI Express* (Intel® 82915G/82915P82915PL Only) Refer to Chapter 0 a for list of PCI Express features, and the PCI Express specification for further details. The (G)MCH is part of a PCI Express root complex. This means it connects a host processor/memory subsystem to a PCI Express hierarchy. The PCI Express architecture is specified in layers. Compatibility with the PCI addressing model (a load-store architecture with a flat address space) is maintained to ensure that all existing applications and drivers operate unchanged. The PCI Express configuration uses standard mechanisms as defined in the PCI Plug-and-Play specification. The initial speed of 1.25 GHz (250 MHz internally) results in 2.5 Gb/s/direction that provides a 250 MB/s communications channel in each direction (500 MB/s total) per lane that is close to twice the data rate of classic PCI. Note: The PCI Express graphics port will operate in x1 mode if a non-graphics card is plugged in. 12.4.1 Transaction Layer The upper layer of the PCI Express architecture is the Transaction Layer. The Transaction Layer’s primary responsibility is the assembly and disassembly of Transaction Layer Packets (TLPs). TLPs are used to communicate transactions (such as read and write as well as certain types of events). The Transaction Layer also manages flow control of TLPs. Note: If the (G)MCH receives two back-to-back malformed packets, the second malformed packet is not trapped or logged. The (G)MCH will not log or identify the second malformed packet. However, the 1st malformed TLP is logged, and is considered a Fatal Error. Link behavior is not guaranteed at that point whether a 2nd malformed TLP is detected or not. 12.4.2 Data Link Layer The middle layer in the PCI Express stack, the Data Link Layer, serves as an intermediate stage between the Transaction Layer and the Physical Layer. Responsibilities of Data Link Layer include link management, error detection, and error correction. 12.4.3 Physical Layer The Physical Layer includes all circuitry for interface operation, including driver and input buffers, parallel-to-serial and serial-to-parallel conversion, PLL(s), and impedance matching circuitry. 232 Datasheet Functional Description R 12.5 Intel® Serial Digital Video Output (SDVO) (Intel® 82915G/82915GV/82915GL/82910GL GMCH Only) The 82915G/82915GV/82915GL/82910GL GMCH SDVO ports are multiplexed with the PCI Express x16 interface. PCI Express and SDVO simultaneous operation is NOT supported, even though SDVO does not require all of the PCI Express lanes. The Intel® SDVO port is the second generation of digital video output from compliant GMCH. The electrical interface is based on the PCI Express interface, although the protocol and timings are completely unique. Where PCI Express runs at a fixed frequency, the frequency of the SDVO interface is dependant upon the active display resolution and timing. The port can be dynamically configured in several modes to support display configurations. Essentially, an SDVO port will transmit display data in a high speed, serial format across differential AC coupled signals. An SDVO port consists of a sideband differential clock pair and a number of differential data pairs. 12.5.1 Intel® SDVO Capabilities SDVO ports can support a variety of display types including LVDS, DVI, Analog CRT, TV-Out and external CE type devices. The GMCH uses an external SDVO device to translate from SDVO protocol and timings to the desired display format and timings. The Internal Graphics Device on the 82915G/82915GV/82915GL/82910GL GMCH can have one or two SDVO ports multiplexed on the x16 PCI Express interface. When an external x16 PCI Express graphics accelerator is not in use, an ADD2 card may be plugged into the x16 connector or if a x16 slot is not present, the SDVO(s) may be located ‘down’ on the motherboard to access the multiplexed SDVO ports and provide a variety of digital display options. The ADD2 card is designed to fit in a x16 PCI Express connector. The ADD2 card can support one or two devices. If a single channel SDVO device is used, it should be attached to the channel B SDVO pins. The ADD2 card can support two separate SDVO devices when the interface is in Dual Independent (82915G only) or Dual Simultaneous Standard modes. The SDVO port defines a two-wire point-to-point communication path between the SDVO device and GMCH. The SDVO control clock and data provide similar functionality to I2C. However, unlike I2C, this interface is intended to be point-to-point (from the GMCH to the SDVO device) and will require the SDVO device to act as a switch and direct traffic from the SDVO control bus to the appropriate receiver. Additionally, this control bus will be able to run at faster speeds (up to 1 MHz) than a traditional I2C interface would. Datasheet 233 Functional Description R 12.5.2 Intel® SDVO Modes The port can be dynamically configured in several modes: • Standard. This mode provides baseline SDVO functionality. Supports Pixel Rates between 25 and 200 MP/s. Utilizes three data pairs to transfer RGB data. • Extended. This mode adds Alpha support to data stream. Extended mode supports Pixel rates between 25 MP/s and 200 MP/s. The mode uses four data channels and is only supported on SDVOB. Leverages channel C (SDVOC) Red pair as the Alpha pair for channel B (SDVOB). Note: Operating in extended SDVO mode is mutually exclusive to the use of a second display on SDVO. • Dual Standard. This mode uses Standard data streams across both SDVOB and SDVOC. Both channels can only run in Standard mode (3 data pairs) and each channel supports Pixel Rates between 25 and 200 MP/s. ⎯ Dual Independent Standard (82915G only). In Dual Independent Standard mode, each SDVO channel will see a different pixel stream. The data stream across SDVOB will not be the same as the data stream across SDVOC. ⎯ Dual Simultaneous Standard. In Dual Simultaneous Standard mode, both SDVO channels will see the same pixel stream. The data stream across SDVOB will be the same as the data stream across SDVOC. The display timings will be identical, but the transfer timings may not be (i.e., SDVOB clocks and data may not be perfectly aligned with SDVOC clock and data as seen at the SDVO device(s)). Since this mode uses just a single data stream, it uses a single pixel pipeline within the GMCH. 234 Datasheet Functional Description R 12.6 Integrated Graphics Device (Intel® 82915G/82915GV/82915GL/82910GL GMCH Only) The GMCH provides a highly integrated graphics accelerator and chipset while allowing a flexible integrated system graphics solution. Figure 12-2 shows a simplified block diagram of the IGD in the GMCH. Figure 12-2. Integrated Graphics Device Block Diagram Video Engine M e m o r y DAC (Analog) 2D Engine Display Engine Port Mux Control SDVOB (Digital) SDVOC (Digital) 3D Engine Gfx_Blk_Dia High bandwidth access to data is provided through the graphics and system memory ports. The GMCH can access graphics data located in system memory at 4.2 GB/s – 8.5 GB/s (depending on memory configuration). The GMCH uses Intel’s Direct Memory Execution model to fetch textures from system memory. The GMCH includes a cache controller to avoid frequent memory fetches of recently used texture data. The GMCH is able to drive an integrated DAC, and/or two SDVO ports (multiplexed with PCI Express) capable of driving an ADD2 card. External SDVO devices are capable of driving a standard progressive scan analog monitor with resolutions up to 2048x1536 @ 75 Hz. The SDVO ports are capable of driving a variety of TV-Out, TMDS, and LVDS transmitters. The GMCH’s Internal Graphics Device (IGD) contains several types of components. The major components in the IGD are the engines, planes, pipes and ports. The GMCH has a 3D/2D Instruction Processing unit to control the 3D and 2D engines. The IGD’s 3D and 2D engines are fed with data through the memory controller. The outputs of the engines are surfaces sent to memory, which are then retrieved and processed by the GMCH planes. The GMCH contains a variety of planes (such as display, overlay, cursor and VGA). A plane consists of rectangular shaped image that has characteristics such as source, size, position, method, and format. These planes get attached to source surfaces that are rectangular memory surfaces with a similar set of characteristics. They are also associated with a particular destination pipe. A pipe consists of a set of combined planes and a timing generator. The GMCH has two independent display pipes, allowing for support of two independent display streams. A port is the destination for the result of the pipe. The GMCH contains three display ports, 1 analog (DAC) Datasheet 235 Functional Description R and two digital (SDVO ports B and C). The ports will be explained in more detail later in the chapter. The entire IGD is fed with data from its memory controller. The GMCH’s graphics performance is directly related to the amount of bandwidth available. If the engines are not receiving data fast enough from the memory controller (e.g., single-channel DDR333), the rest of the IGD will also be affected. The rest of this chapter will focus on explaining the IGD components, their limitations and dependencies. 12.6.1 3D Engine The 3D engine of GMCH has been designed with a deep pipelined architecture, where performance is maximized by allowing each stage of the pipeline to simultaneously operate on different primitives or portions of the same primitive. GMCH supports Perspective-Correct Texture Mapping, Multitextures, Bump-Mapping, Cubic Environment Maps, Bilinear, Trilinear and Anisotropic MIP mapped filtering, Gouraud shading, Alpha-blending, Vertex and Per Pixel Fog and Z/W Buffering. The 3D pipeline subsystem performs the 3D rendering acceleration. The main blocks of the pipline are the Setup Engine, Scan Converter, Texture Pipeline, and Raster Pipeline. A typical programming sequence would be to send instructions to set the state of the pipeline followed by rending instructions containing 3D primitive vertex data. The engine’s performance is dependent on the memory bandwidth available. Systems that have more bandwidth available will outperform systems with less bandwidth. The engine’s performance is also dependent on the core clock frequency. The higher the frequency, the more data is processed. 12.6.2 Setup Engine The setup stage of the pipeline takes the input data associated with each vertex of a 3D primitive and computes the various parameters required for scan conversion. In formatting this data, the GMCH maintains sub-pixel accuracy. 12.6.2.1 3D Primitives and Data Formats Support The 3D primitives rendered by GMCH are points, lines, discrete triangles, line strips, triangle strips, triangle fans and polygons. In addition to this, GMCH supports the Microsoft DirectX* Flexible Vertex Format (FVF), which enables the application to specify a variable length of parameter list obviating the need for sending unused information to the hardware. Strips, Fans and Indexed Vertices as well as FVF, improve the vertex rate delivered to the setup engine significantly. 236 Datasheet Functional Description R 12.6.2.2 Pixel Accurate “Fast” Scissoring and Clipping Operation The GMCH supports 2D clipping to a scissor rectangle within the drawing window. Objects are clipped to the scissor rectangle, avoiding processing pixels that fall outside the rectangle. The GMCH’s clipping and scissoring in hardware reduce the need for software to clip objects, and thus improve performance. During the setup stage, GMCH clips objects to the scissor window. A scissor rectangle accelerates the clipping process by allowing the driver to clip to a bigger region than the hardware renders to. The scissor rectangle needs to be pixel accurate, and independent of line and point width. The GMCH will support a single scissor box rectangle that can be enabled or disabled. The rectangle is defined as an Inclusive box. Inclusive is defined as “draw the pixel if it is inside the scissor rectangle”. 12.6.2.3 Depth Bias The GMCH supports source Depth Biasing in the Setup Engine. The Depth Bias value is specified in the vertex command packet on a per primitive basis. The value ranges from -1 to 1. The Depth Bias value is added to the z or w value of the vertices. This is used for coplanar polygon priority. If two polygons are to be rendered that are coplanar, due to the inherent precision differences induced by unique x, y and z values, there is no guarantee which polygon will be closer or farther. By using Depth Bias, it is possible to offset the destination z value (compare value) before comparing with the new z value. 12.6.2.4 Backface Culling As part of the setup, the GMCH discards polygons from further processing, if they are facing away from or towards the user’s viewpoint. This operation, referred to as “Back Face Culling” is accomplished based on the “clockwise” or “counter-clockwise” orientation of the vertices on a primitive. This can be enabled or disabled by the driver. 12.6.2.5 Scan Converter Working on a per-polygon basis, the Scan Converter uses the vertex and edge information is used to identify all pixels affected by features being rendered. 12.6.2.6 Pixel Rasterization Rules The GMCH supports both OpenGL and D3D pixel rasterization rules to determine whether a pixel is filled by the triangle or line. For both D3D and OpenGL modes, a top-left filling convention for filling geometry will be used. Pixel rasterization rule on rectangle primitive is also supported using the top-left fill convention. 12.6.2.7 2D Functionality The stretch BLT function can stretch source data in the X and Y directions to a destination larger or smaller than the source. Stretch BLT functionality expands a region of memory into a larger or smaller region using replication and interpolation. The stretch BLT function also provides format conversion and data alignment. Datasheet 237 Functional Description R 12.6.3 Texture Engine The GMCH allows an image, pattern, or video to be placed on the surface of a 3D polygon. The texture processor receives the texture coordinate information from the setup engine and the texture blend information from the scan converter. The texture processor performs texture color or ChromaKey matching, texture filtering (anisotropic, trilinear, and bilinear interpolation), and YUV to RGB conversions. 12.6.3.1 Perspective Correct Texture Support A textured polygon is generated by mapping a 2D texture pattern onto each pixel of the polygon. A texture map is like wallpaper pasted onto the polygon. Since polygons are rendered in perspective, it is important that texture be mapped in perspective as well. Without perspective correction, texture is distorted when an object recedes into the distance. 12.6.3.2 Texture Formats and Storage The GMCH supports up to 32 bits of color for textures. 12.6.3.3 Texture Decompression DirectX supports Texture Compression to reduce the bandwidth required to deliver textures. As the textures’ average size gets larger with higher color depth and multiple textures become the norm, it becomes increasingly important to provide a mechanism for compressing textures. Texture decompression formats supported include DXT1, DXT2, DXT3, DXT4, DXT5 and FXT1. 12.6.3.4 Texture ChromaKey ChromaKey describes a method of removing a specific color or range of colors from a texture map before it is applied to an object. For “nearest” texture filter modes, removing a color simply makes those portions of the object transparent (the previous contents of the back buffer show through). For “linear“ texture filtering modes, the texture filter is modified if only the non-nearest neighbor texels match the key (range). 12.6.3.5 Anti-Aliasing Aliasing is one of the artifacts that degrade image quality. In its simplest manifestation, aliasing causes the jagged staircase effects on sloped lines and polygon edges. Another artifact is the moiré patterns that occur as a result of a very small number of pixels available on screen to contain the data of a high resolution texture map. More subtle effects are observed in animation, where very small primitives blink in and out of view. 12.6.3.6 Texture Map Filtering The GMCH supports many texture mapping modes. Perspective correct mapping is always performed. As the map is fitted across the polygon, the map can be tiled, mirrored in either the U or V directions, or mapped up to the end of the texture and no longer placed on the object (this is known as clamp mode). The way a texture is combined with other object attributes is also definable. 238 Datasheet Functional Description R The GMCH supports up to 12 Levels-of-Detail (LODs) ranging in size from 2048x2048 to 1x1 texels. Textures need not be square. Included in the texture processor is a texture cache, which provides efficient MIP-mapping. The GMCH supports 7 types of texture filtering: • Nearest (aka Point Filtering): Texel with coordinates nearest to the desired pixel is used. (This is used if only one LOD is present). • Linear (aka Bilinear Filtering): A weighted average of a 2x2 area of texels surrounding the desired pixel is used. (This is used if only one LOD is present). • Nearest MIP Nearest (aka Point Filtering): This is used if many LODs are present. The nearest LOD is chosen and the texel with coordinates nearest to the desired pixel is used. • Linear MIP Nearest (Bilinear MIP Mapping): This is used if many LODs are present. The nearest LOD is chosen and a weighted average of a 2x2 area of texels surrounding the desired pixel is used (four texels). This is also referred to as Bilinear MIP Mapping. • Nearest MIP Linear (Point MIP Mapping): This is used if many LODs are present. Two appropriate LODs are selected and within each LOD the texel with coordinates nearest to the desired pixel is selected. The Final texture value is generated by linear interpolation between the two texels selected from each of the MIP Maps. • Linear MIP Linear (Trilinear MIP Mapping): This is used if many LODs are present. Two appropriate LODs are selected and a weighted average of a 2x2 area of texels surrounding the desired pixel in each MIP Map is generated (four texels per MIP Map). The Final texture value is generated by linear interpolation between the two texels generated for each of the MIP Maps. Trilinear MIP Mapping is used minimize the visibility of LOD transitions across the polygon. • Anisotropic MIP Nearest (Anisotropic Filtering): This is used if many LODs are present. The nearest LOD-1 level will be determined for each of four sub-samples for the desired pixel. These four sub-samples are then bilinear filtered and averaged together. Both D3D (DirectX 6.0 and later) and OpenGL (Revision 1.1) allow support for all these filtering modes. 12.6.3.7 Multiple Texture Composition The GMCH also performs multiple texture composition. This allows the combination of two or greater MIP Maps to produce a new one with new LODs and texture attributes in a single or iterated pass. Flexible vertex format support allows multitexturing because it makes it possible to pass more than one texture in the vertex structure. 12.6.3.8 Bi-Cubic Filter (4x4 Programmable Texture Filter) A bi-cubic texture filter can be selected instead of the bilinear filter. The implementation is of a 4x4 separable filter with loadable coefficients. A 4x4 filter can be used for providing high-quality up/ down scaling of 2D or 3D rendered images. Datasheet 239 Functional Description R 12.6.3.9 Cubic Environment Mapping Environment maps allow applications to render scenes with complex lighting and reflections while significantly decreasing processor load. There are several methods to generate environment maps (such as, spherical, circular and cubic). The GMCH supports cubic reflection mapping over spherical and circular since it is the best choice to provide real-time environment mapping for complex lighting and reflections. Cubic Mapping requires a texture map for each of the 6 cube faces. These can be generated by pointing a camera with a 90-degree field-of-view in the appropriate direction. Per-vertex vectors (normal, reflection or refraction) are interpolated across the polygon and the intersection of these vectors with the cube texture faces is calculated. Texel values are then read from the intersection point on the appropriate face and filtered accordingly. 12.6.4 Raster Engine The Raster Engine is where the color data (such as fogging, specular RGB, texture map blending, etc.) is processed. The final color of the pixel is calculated and the RGBA value combined with the corresponding components resulting from the Texture Engine. These textured pixels are modified by the specular and fog parameters. These specular highlighted, fogged, textured pixels are color blended with the existing values in the frame buffer. In parallel, stencil, alpha and depth buffer tests are conducted which will determine whether the Frame and Depth Buffers will be updated with the new pixel values. 12.6.4.1 Texture Map Blending Multiple Textures can be blended together in an iterative process and applied to a primitive. The GMCH allows up to four texture coordinates and texture maps to be specified onto the same polygon. Also, the GMCH supports using a texture coordinate set to access multiple texture maps. State variables in multiple texture are bound to texture coordinates, texture map or texture blending. 12.6.4.2 Combining Intrinsic and Specular Color Components The GMCH allows an independently specified and interpolated “specular RGB” attribute to be added to the post-texture blended pixel color. This feature provides a full RGB specular highlight to be applied to a textured surface, permitting a high-quality reflective colored lighting effect not available in devices which apply texture after the lighting components have been combined. If specular-add state variable is disabled, only the resultant colors from the map blending are used. If this state variable is enabled, RGB values from the output of the map blending are added to values for RS, GS, BS on a component by component basis. 12.6.4.3 Color Shading Modes The Raster Engine supports the flat and Gouraud shading modes. These shading modes are programmed by the appropriate state variables issued through the command stream. Flat shading is performed by smoothly interpolating the vertex intrinsic color components (Red, Green, Blue), Specular Highlights(R,G,B), Fog, and Alpha to the pixel, where each vertex color has the same value. The setup engine substitutes one of the vertex’s attribute values for the other 240 Datasheet Functional Description R two vertices attribute values thereby creating the correct flat shading terms. This condition is set up by the appropriate state variables issued prior to rendering the primitive. OpenGL and D3D use a different vertex to select the flat shaded color. This vertex is defined as the “provoking vertex”. In the case of strips/fans, after the first triangle, attributes on every vertex that define a primitive are used to select the flat color of the primitive. A state variable is used to select the “flat color” prior to rendering the primitive. Gouraud shading is performed by smoothly interpolating the vertex intrinsic color components (Red, Green, Blue). Specular Highlights (R,G,B), Fog, and Alpha to the pixel, where each vertex color has a different value. All the attributes can be selected independently from one of the shading modes by setting the appropriate value state variables. 12.6.4.4 Color Dithering Color Dithering helps to hide color quantization errors. Color Dithering takes advantage of the human eye’s propensity to “average” the colors in a small area. Input color, alpha, and fog components are converted from 8-bit components to 5- or 6- bit component by dithering. Dithering is performed on blended textured pixels. In 32-bit mode, dithering is not performed on the components 12.6.4.5 Vertex and Per Pixel Fogging Fogging is used to create atmospheric effects (such as low visibility conditions in flight simulatortype games). It adds another level of realism to computer-generated scenes. Fog can be used for depth cueing or hiding distant objects. With fog, distant objects can be rendered with fewer details (fewer polygons), thereby improving the rendering speed or frame rate. Fog is simulated by attenuating the color of an object with the fog color as a function of distance. Higher fog density produces lower visibility for distant objects. There are two ways to implement the fogging technique: per-vertex (linear) fogging and per-pixel (non-linear) fogging. The per-vertex method interpolates the fog value at the vertices of a polygon to determine the fog factor at each pixel within the polygon. This method provides realistic fogging as long as the polygons are small. With large polygons (such as a ground plane depicting an airport runway), the per-vertex technique results in unnatural fogging. The GMCH supports both types of fog operations, vertex and per pixel or table fog. If fog is disabled, the incoming color intensities are passed unchanged to the destination blend unit. 12.6.4.6 Alpha Blending (Frame Buffer) Alpha Blending adds the material property of transparency or opacity to an object. Alpha blending combines a source pixel color (RSGSBS) and alpha (AS) component with a destination pixel color (RDGDBD) and alpha (AD) component. For example, this is so that a glass surface on top (source) of a red surface (destination) would allow much of the red base color to show through. Blending allows the source and destination color values to be multiplied by programmable factors and then combined via a programmable blend function. The combined and independent selection of factors and blend functions for color and alpha are supported. Datasheet 241 Functional Description R 12.6.4.7 Microsoft DirectX* API and SGI OpenGL* API Logic Ops Both APIs provide a mode to use bitwise ops in place of alpha blending. This is used for rubberbanding (i.e., draw a rubber band outline over the scene using an XOR operation). Drawing it again restores the original image without having to do a potentially expensive redraw. 12.6.4.8 Color Buffer Formats: 8-, 16-, or 32-bits per Pixel (Destination Alpha) The Raster Engine supports 8-bit, 16-bit, and 32-bit Color Buffer Formats. The 8-bit format is used to support planar YUV420 format, which used only in Motion Compensation and Arithmetic Stretch format. The bit format of Color and Z will be allowed to mix. The GMCH supports both double and triple buffering, where one buffer is the primary buffer used for display and one or two are the back buffer(s) used for rendering. The frame buffer of the GMCH contains at least two hardware buffers: the Front Buffer (display buffer) and the Back Buffer (rendering buffer). While the back buffer may actually coincide with (or be part of) the visible display surface, a separate (screen or window-sized) back buffer is used to permit double-buffered drawing. That is, the image being drawn is not visible until the scene is complete and the back buffer made visible (via an instruction) or copied to the front buffer (via a 2D BLT operation). Rendering to one and displaying from the other remove the possibility of image tearing. This also speeds up the display process over a single buffer. Additionally, triple back buffering is also supported. The instruction set of the GMCH provides a variety of controls for the buffers (e.g., initializing, flip, clear, etc.). 12.6.4.9 Depth Buffer The Raster Engine can read and write from this buffer and use the data in per fragment operations that determine whether resultant color and depth value of the pixel for the fragment are to be updated or not. Typical applications for entertainment or visual simulations with exterior scenes require far/near ratios of 1000 to 10000. At 1000, 98% of the range is spent on the first 2% of the depth. This can cause hidden surface artifacts in distant objects, especially when using 16-bit depth buffers. A 24-bit Z-buffer provides 16 million Z-values, as opposed to only 64 K with a 16-bit Z buffer. With lower Z-resolution, two distant overlapping objects may be assigned the same Z-value. As a result, the rendering hardware may have a problem resolving the order of the objects, and the object in the back may appear through the object in the front. By contrast, when W (or eye-relative Z) is used, the buffer bits can be more evenly allocated between the near and far clip planes in world space. The key benefit is that the ratio of far and near is no longer an issue, allowing applications to support a maximum range of miles, yet still get reasonably accurate depth buffering within inches of the eye point. The GMCH supports a flexible format for the floating-point W buffer, wherein the number of exponent bits is programmable. This allows the driver to determine variable precision as a function of the dynamic range of the W (screen-space Z) parameter. The selection of depth buffer size is relatively independent of the color buffer. A 16-bit Z/W or 24-bit Z/W buffer can be selected with a 16-bit color buffer. Z buffer is not supported in 8-bit mode. 242 Datasheet Functional Description R 12.6.4.10 Stencil Buffer The Raster Engine provides 8-bit stencil buffer storage in 32-bit mode and the ability to perform stencil testing. Stencil testing controls 3D drawing on a per pixel basis, conditionally eliminating a pixel on the outcome of a comparison between a stencil reference value and the value in the stencil buffer at the location of the source pixel being processed. They are typically used in multipass algorithms to achieve special effects, such as decals, outlining, shadows and constructive solid geometry rendering. 12.6.4.11 Projective Textures The GMCH supports two simultaneous projective textures at full rate processing, and four textures at half rate. These textures require three floating point texture coordinates to be included in the Flexible Vertex Format (FVF). Projective textures enable special effects (such as projecting spot light textures obliquely onto walls, etc.). 12.6.5 2D Engine The GMCH contains BLT functionality, and an extensive set of 2D instructions. To take advantage of the 3D drawing engine’s functionality, some BLT functions (such as Alpha BLTs, arithmetic (bilinear) stretch BLTs, rotations, transposing pixel maps, limited color space conversion, and DIBs) make use of the 3D renderer. 12.6.5.1 GMCH VGA Registers The 2D registers are a combination of registers defined by IBM when the Video Graphics Array (VGA) was first introduced and others that Intel has added to support graphics modes that have color depths, resolutions, and hardware acceleration features that go beyond the original VGA standard. 12.6.5.2 Logical 128-bit Fixed BLT and 256 Fill Engine Use of this BLT engine accelerates the Graphical User Interface (GUI) of Microsoft Windows* operating systems. The 128-bit GMCH BLT Engine provides hardware acceleration of block transfers of pixel data for many common Windows operations. The term BLT refers to a block transfer of pixel data between memory locations. The BLT engine can be used for the following: • Move rectangular blocks of data between memory locations • Data Alignment • Perform logical operations (raster ops) The rectangular block of data does not change as it is transferred between memory locations. The allowable memory transfers are between: cacheable system memory and frame buffer memory, frame buffer memory and frame buffer memory, and within system memory. Data to be transferred can consist of regions of memory, patterns, or solid color fills. A pattern will always be 8x8 pixels wide and may be 8, 16, or 32 bits per pixel. The GMCH BLT engine has the ability to expand monochrome data into a color depth of 8, 16, or 32 bits. BLTs can be either opaque or transparent. Opaque transfers move the data specified to the Datasheet 243 Functional Description R destination. Transparent transfers compare destination color to source color and write according to the mode of transparency selected. Data is horizontally and vertically aligned at the destination. If the destination for the BLT overlaps with the source memory location, the GMCH can specify which area in memory to begin the BLT transfer. Hardware is included for all 256 raster operations (Source, Pattern, and Destination) defined by Microsoft, including transparent BLT. The GMCH has instructions to invoke BLT and stretch BLT operations, permitting software to set up instruction buffers and use batch processing. The GMCH can perform hardware clipping during BLTs. 12.6.6 12.6.6.1 Video Engine Hardware Motion Compensation The Motion Compensation (MC) process consists of reconstructing a new picture by predicting (either forward, backward, or bi-directionally) the resulting pixel colors from one or more reference pictures. The GMCH receives the video stream and implements Motion Compensation and subsequent steps in hardware. Performing Motion Compensation in hardware reduces the processor demand of software-based MPEG-2 decoding, and thus improves system performance. The Motion Compensation functionality is overloaded onto the texture cache and texture filter. The texture cache is used to typically access the data in the reconstruction of the frames and the filter is used in the actual motion compensation process. To support this overloaded functionality the texture cache additionally support the YUV420 planar input formats. 12.6.6.2 Sub-Picture Support Sub-picture is used for two purposes; one is Subtitles for movie captions, etc. (that are superimposed on a main picture), and the other is Menus used to provide some visual operation environments the user of a content player. DVD allows movie subtitles to be recorded as Sub-pictures. On a DVD disc, it is called "Subtitle" because it has been prepared for storing captions. Since the disc can have a maximum of 32 tracks for Subtitles, they can be used for various applications, for example, as Subtitles in different languages or other information to be displayed. There are two kinds of Menus; the System Menus and other In-Title Menus. First, the System Menus are displayed and operated at startup of or during the playback of the disc or from the stop state. Second, In-Title menus can be programmed as a combination of Sub-picture and Highlight commands to be displayed during playback of the disc. The GMCH supports sub-picture for DVD and DBS by mixing the two video streams via alpha blending. Unlike color keying, alpha blending provides a softer effect and each pixel that is displayed is a composite between the two video stream pixels. The GMCH can use four methods when dealing with sub-pictures. The flexibility enables the GMCH to work with all sub- picture formats. 244 Datasheet Functional Description R 12.6.7 Planes A plane consists of rectangular shaped image that has characteristics such as source, size, position, method, and format. These planes get attached to source surfaces, which are rectangular memory surfaces with a similar set of characteristics. They are also associated with a particular destination pipe. 12.6.7.1 Cursor Plane The cursor planes are one of the simplest display planes. With a few exceptions, the cursor plane has a fixed size of 64x64 and a fixed Z-order (top). In legacy modes, cursor can cause the display data below it to be inverted. 12.6.7.2 Overlay Plane The overlay engine provides a method of merging either video capture data (from an external Video Capture device) or data delivered by the processor, with the graphics data on the screen. The source data can be mirrored horizontally or vertically or both. Source/Destination Color Keying/ChromaKeying Overlay source/destination ChromaKeying enables blending of the overlay with the underlying graphics background. Destination color keying/ChromaKeying can be used to handle occluded portions of the overlay window on a pixel by pixel basis that is actually an underlay. Destination ChromaKeying would only be used for YUV passthrough to TV. Destination color keying supports a specific color (8- or 15-bit) mode as well as 32-bit alpha blending. Source color keying/ChromaKeying is used to handle transparency based on the overlay window on a pixel by pixel basis. This is used when “blue screening” an image to overlay the image on a new background later. Gamma Correction To compensate for overlay color intensity loss due to the non-linear response between display devices, the overlay engine supports independent gamma correction. This allows the overlay data to be converted to linear data or corrected for the display device when not blending. YUV to RGB Conversion The format conversion can be bypassed in the case of RGB source data. The format conversion assumes that the YUV data is input in the 4:4:4 format and uses the full range scale. Maximum Resolution and Frequency The maximum frequency supported by the overlay logic is 180 MHz. The maximum resolution is dependent on a number of variables (e.g., memory speed, memory latency, port selected, pipe selected, mode definition). Datasheet 245 Functional Description R Deinterlacing Support For display on a progressive computer monitor, interlaced data that has been formatted for display on interlaced monitors (TV) needs to be de-interlaced. The simple approaches to de-interlacing create unwanted display artifacts. More advanced de-interlacing techniques have a large cost associated with them. The compromise solution is to provide a low cost but effective solution and enable both hardware and software based external solutions. Software based solutions are enabled through a high bandwidth transfer to system memory and back. 12.6.7.3 Advanced Deinterlacing and Dynamic Bob and Weave Interlaced data that originates from a video camera creates two fields that are temporally offset by 1/60 of a second. There are several schemes to deinterlace the video stream: line replication, vertical filtering, field merging, and vertical temporal filtering. Field merging takes lines from the previous field and inserts them into the current field to construct the frame; this is known as Weaving. This is the best solution for images with little motion however, showing a frame that consists of the two fields will have serration or feathering of moving edges when there is motion in the scene. Vertical filtering or “Bob” interpolates adjacent lines rather than replicating the nearest neighbor. This is the best solution for images with motion; however, it will have reduced spatial resolution in areas that have no motion and introduces aliasing. In the absence of any other deinterlacing, these form the baseline and are supported by the GMCH. Scaling Filter and Control The scaling filter has three vertical taps and five horizontal taps. Arbitrary scaling (per pixel granularity) for any video source (YUV422 or YUV420) format is supported. The overlay logic can scale an input image up to 1600X1200with no major degradation in the filter used as long as the maximum frequency limitation is met. Display resolution and refresh rate combinations where the dot clock is greater than the maximum frequency require the overlay to use pixel replication. 12.6.8 Pipes The display consists of two pipes. The Pipes can operate in a single-wide or “double-wide” mode at 2x graphics core clock though they are effectively limited by the respective display port. The display planes and the cursor plane will provide a “double wide” mode to feed the pipe. 12.6.8.1 Clock Generator Units (DPLL) The clock generator units provide a stable frequency for driving display devices. It operates by converting an input reference frequency into an output frequency. The timing generators take their input from internal DPLL devices that are programmable to generate pixel clocks in the range of 25–400 MHz. Accuracy for VESA timing modes is required to be within ± 0.5%. The DPLL can take a reference frequency from the external reference input (DREFCLKINN/P), the TV clock input (TVCLKIN). 246 Datasheet Functional Description R 12.7 Display Interfaces (Intel® 82915G/82915GV/82915GL/ 82910GL GMCH Only) The GMCH has three display ports; one analog and two digital. Each port can transmit data according to one or more protocols. The digital ports are connected to an external device that converts one protocol to another. Examples of this are TV encoders, external DACs, LVDS transmitters, and TMDS transmitters. Each display port has control signals that may be used to control, configure and/or determine the capabilities of an external device. The analog port is a dedicated port (not multiplexed) on the 82915GV/82915GL/82910GL GMCH. For the 82915G GMCH, the SDVO ports B and C are multiplexed with the PCI Express graphics interface and are not available if an external PCI Express graphics device is in use. When a 915G Express chipset system uses a PCI Express graphics connector, SDVO ports B and C can be used via an ADD2 (Advanced Digital Display 2) card. Ports B and C can also operate in dualchannel mode, where the data bus is connected to both display ports, allowing a single device to take data at twice the pixel rate. • The GMCH’s analog port uses an integrated 400 MHz RAMDAC that can directly drive a standard progressive scan analog monitor up to a resolution of 2048x1536 pixels with 32-bit color at 85 Hz. • The GMCH’s SDVO ports are each capable of driving a 200-MP pixel rate. Each port is capable of driving a digital display up to 1600x1200 @ 60Hz. When in dual-channel mode, the GMCH can drive a flat panel up to 2048x1536 @ 85 Hz or dCRT/HDTV up to 1920x1080 @ 85 Hz. The GMCH is compliant with DVI Specification 1.0. When combined with a DVI compliant external device and connector, the GMCH has a high speed interface to a digital display (e.g., flat panel or digital CRT). Datasheet 247 Functional Description R Table 12-6. Display Port Characteristics Interface Protocol Analog RGB DAC HSYNC VSYNC Signals BLANK STALL Field Display_Enable Image Aspect Ratio Pixel Aspect Ratio Voltage Clock Max Rate Format Control Bus External Device Connector No No No No Digital Port B DVO 1.0 Yes Enable/Polarity Yes Enable/Polarity Yes 1 Digital Port C DVO 1.0 Yes 1 Yes Yes Yes Yes No 1 Programmable and typically 1.33:1 or 1.78:1 Square RGB 0.7 V p-p NA 400 Mpixel Analog RGB DDC1/DDC2B No VGA/DVI-I PCI Express* PCI Express* Differential 200/400 Mpixel RGB 8:8:8 YUV 4:4:4 DDC2B TMDS/LVDS Transmitter /TV Encoder DVI/CVBS/S-Video/Component/SCART NOTES: 1. Single signal software selectable between display enable and Blank#. 248 Datasheet Functional Description R 12.7.1 Analog Display Port Characteristics The analog display port provides a RGB signal output along with a HSYNC and VSYNC signal. There is an associated DDC signal pair that is implemented using GPIO pins dedicated to the analog port. The intended target device is for a CRT based monitor with a VGA connector. Display devices (such as LCD panels) with analog inputs may work satisfactory but no functionality has been added to the signals to enhance that capability. Table 12-7. Analog Port Characteristics Signal Port Characteristic Voltage Range Monitor Sense RGB Analog Copy Protection Sync on Green Voltage Enable/Disable HSYNC VSYNC Polarity adjust Composite Sync Support Special Flat Panel Sync Stereo Sync Voltage DDC Control Through GPIO interface No No 2.5 V Port control VGA or port control No No No Externally buffered to 5V Support 0.7 V p-p only Analog Compare 12.7.1.1 Integrated RAMDAC The display function contains a RAM-based Digital-to-Analog Converter (RAMDAC) that transforms the digital data from the graphics and video subsystems to analog data for the CRT monitor. The GMCH’s integrated 400 MHz RAMDAC supports resolutions up to 2048 x 1536 @ 85Hz. Three 8-bit DACs provide the RED, GREEN, and BLUE signals to the monitor. 12.7.1.2 Sync Signals HSYNC and VSYNC signals are digital and conform to TTL signal levels at the connector. Since these levels cannot be generated internal to the device, external level shifting buffers are required. These signals can be polarity adjusted and individually disabled in one of the two possible states. The sync signals power up disabled in the high state. No composite sync or special flat panel sync support is included. 12.7.1.3 VESA/VGA Mode VESA/VGA mode provides compatibility for pre-existing software that set the display mode using the VGA CRTC registers. Timings are generated based on the VGA register values and the timing generator registers are not used. Datasheet 249 Functional Description R 12.7.1.4 DDC (Display Data Channel) DDC is a standard defined by VESA. Its purpose is to allow communication between the host system and display. Both configuration and control information can be exchanged allowing plugand-play systems to be realized. Support for DDC 1 and 2 is implemented. The GMCH uses the DDC_CLK and DDC_DATA signals to communicate with the analog monitor. The GMCH generates these signals at 2.5 V. External pull-up resistors and level shifting circuitry should be implemented on the board. The GMCH implements a hardware GMBus controller that can be used to control these signals allowing for transactions speeds up to 400 kHz. 12.7.2 Digital Display Interface The GMCH has several options for driving digital displays. The GMCH contains two SDVO ports that are multiplexed on the PCI Express* x16 Graphics Interface. When an external PCI Express* x16 Graphics Interface graphics accelerator is not present, the GMCH can use the multiplexed SDVO ports to provide extra digital display options. These additional digital display capabilities may be provided through an ADD2 card that is designed to plug in to a PCI Express connector. 12.7.2.1 Digital Display Channels – SDVOB and SDVOC The GMCH has the capability to support digital display devices through two SDVO ports. When an external graphics accelerator is used via the PCI Express* x16 Graphics Interface port, these SDVO ports are not available. The shared SDVO ports each support a pixel clock up to 200 MHz and can support a variety of transmission devices. When using a dual-channel external transmitter, it will be possible to pair the two SDVO ports in dual-channel mode to support a single digital display with higher resolutions and refresh rates. In this mode, GMCH is capable of driving pixel clock up to 400 MHz. SDVO_CTRLDATA is an open-drain signal that will act as a strap during reset to tell the GMCH whether the interface is a PCI Express interface or an SDVO interface. When implementing SDVO, either via ADD2 cards or with a down device, a pull-up is placed on this line to signal to the GMCH to run in SDVO mode and for proper GMBus operation. 12.7.2.2 ADD2 Card When a 915G Express chipset platform uses a PCI Express* x16 Graphics Interface connector, the multiplexed SDVO ports may be used via an ADD2 card. The ADD2 card will be designed to fit a standard PCI Express (x16) connector. 12.7.2.2.1 TMDS Capabilities The GMCH is compliant with DVI Specification 1.0. When combined with a DVI compliant external device and connector, the GMCH has a high speed interface to a digital display (e.g., flat panel or digital CRT). When combining the two multiplexed SDVO ports, the GMCH can drive a flat panel up to 2048x1536 or a dCRT/HDTV up to 1920x1080. Flat Panel is a fixed resolution display. The GMCH supports panel fitting in the transmitter, receiver or an external 250 Datasheet Functional Description R device, but has no native panel fitting capabilities. The GMCH will, however, provide unscaled mode where the display is centered on the panel. 12.7.2.2.2 LVDS Capabilities The GMCH may use the multiplexed SDVO ports to drive a LVDS transmitter. Flat Panel is a fixed resolution display. The GMCH supports panel fitting in the transmitter, receiver or an external device, but has no native panel fitting capabilities. The GMCH will, however, provide unscaled mode where the display is centered on the panel. The GMCH supports scaling in the LVDS transmitter through the SDVO stall input pair. 12.7.2.2.3 TV-Out Capabilities Although traditional TVs are not digital displays, the GMCH uses a digital display channel to communicate with a TV-Out transmitter. For that reason, the GMCH considers a TV-Output to be a digital display. GMCH supports NTSC and PAL standard definition formats. The GMCH generates the proper timing for the external encoder. The external encoder is responsible for generation of the proper format signal. Since the multiplexed SDVO interface is a NTSC/PAL/SECAM display on the TV-Out port , it can be configured to be the boot device. It is necessary to ensure that appropriate BIOS support is provided. If EasyLink is supported in the GMCH, then this mechanism could be used to interrogate the display device. The TV-Out interface on the GMCH is addressable as a master device. This allows an external TV encoder device to drive a pixel clock signal on SDVO_TVClk[+/-] that the GMCH uses as a reference frequency. The frequency of this clock is dependent on the output resolution required. Flicker Filter and Overscan Compensation The overscan compensation scaling and the flicker filter is done in the external TV encoder chip. Care must be taken to allow for support of TV sets with high performance de-interlacers and progressive scan displays connected to by way of a non-interlaced signal. Timing will be generated with pixel granularity to allow more overscan ratios to be supported. Direct YUV from Overlay When source material is in the YUV format and is destined for a device that can take YUV format data in, it is desired to send the data without converting it to RGB. This avoids the truncation errors associated with multiple color conversion steps. The common situation will be that the overlay source data is in the YUV format and will bypass the conversion to RBG as it is sent to the TV port directly. Sync Lock Support Sync lock to the TV will be done using the external encoders PLL combined with the display phase detector mechanism. The availability of this feature will be used to determine which external encoder is in use. Datasheet 251 Functional Description R Analog Content Protection Analog content protection is provided through the external encoder using Macrovision 7.01. DVD software must verify the presence of a Macrovision TV encoder before playback continues. Simple attempts to disable the Macrovision operation must be detected. Connectors Target TV connectors support includes the CVBS, S-Video, Component, and SCART connectors. The external TV encoder in use will determine the method of support. 12.7.2.2.4 Control Bus Communication to SDVO registers and if utilized, ADD2 PROMs and monitor DDCs, are accomplished by using the SDVO_CTRLDATA and SDVO_CTRLCLK signals through the SDVO device. These signals run up to 1 MHz and connect directly to the SDVO device. The SDVO device is then responsible for routing the DDC and PROM data streams to the appropriate location. Consult SDVO device datasheets for level shifting requirements of these signals. Intel® SDVO Modes The port can be dynamically configured in several modes: • Standard – This mode provides baseline SDVO functionality. The mode supports pixel rates between 25 and 200 MP/s. It uses three data pairs to transfer RGB data. • Extended (82915G only) – This mode adds Alpha support to data stream. Extended mode supports pixel rates between 25 MHz and 200 MP/s. The mode uses four data channels and is only supported on SDVOB. It leverages channel C (SDVOC) Red pair as the Alpha pair for channel B (SDVOB). • Dual Standard – This mode uses standard data streams across both SDVOB and SDVOC. Both channels can only run in Standard mode (3 data pairs) and each channel supports Pixel Rates between 25 and 200 MP/s. ⎯ Dual Independent Standard (82915G only) - In Dual Independent Standard mode, each SDVO channel will see a different pixel stream. The data stream across SDVOB will not be the same as the data stream across SDVOC. This mode is only supported on the 82915G/82915GV/82915GL/82910GL GMCH. ⎯ Dual Simultaneous Standard - In Dual Simultaneous Standard mode, both SDVO channels will see the same pixel stream. The data stream across SDVOB will be the same as the data stream across SDVOC. The display timings will be identical, but the transfer timings may not be (i.e., SDVOB clocks and data may not be perfectly aligned with SDVOC clock and data as seen at the SDVO device(s)). Since this uses just a single data stream, it uses a single pixel pipeline within the GMCH. 12.7.3 Multiple Display Configurations Microsoft Windows* 2000 and Windows* XP operating systems have enabled support for multimonitor display. Since the GMCH has several display ports available for its two pipes, it can support up to two different images on different display devices. Timings and resolutions for these two images may be different. The GMCH supports Intel Dual Display Clone, Intel Dual Display Twin, and Extended Desktop. 252 Datasheet Functional Description R Intel Dual Display Clone uses both display pipes to drive the same content, at the same resolution and color depth to two different displays. This configuration allows for different refresh rates on each display. Intel Dual Display Twin uses one of the display pipes to drive the same content, at the same resolution, color depth, and refresh rates to two different displays. Extended Desktop (82915G only) uses both display pipes to drive different content, at potentially different resolutions, refresh rates, and color depths to two different displays. This configuration allows for a larger Windows Desktop by using both displays as a work surface. Note: The GMCH graphics engine is also incapable of operating in parallel with an external PCI Express graphics device. The GMCH graphics engine can, however, work in conjunction with a PCI graphics adapter. 12.8 Power Management Power Management capabilities of the (G)MCH include the following: • ACPI 1.0b support • ACPI S0, S3, S4, S5, C0, C1, C2, C3, C4 • Enhanced power management state transitions for increasing time the processor spends in low power states • Internal Graphics Display Device Control D0, D1, D2, D3 (82915G/82915GV/82915GL/82910GL GMCH only) • Graphics Adapter States: D0, D3. • PCI Express Link States: L0, L0s, L1, L2/L3 Ready, L3 • Conditional memory Self-Refresh during C2, C3, and C4 states 12.9 Clocking The (G)MCH has a total of 5 PLLs providing the internal clocks. The PLLs are: • Host PLL – This PLL generates the main core clocks in the host clock domain. The host PLL is used to generate memory and internal graphics core clocks. It uses the Host clock (H_CLKIN) as a reference. • PCI Express PLL (82915G/92915P/82915PL (G)MCH Only) – This PLL generates all PCI Express related clocks, including the Direct Media Interface that connects to the ICH6. This PLL uses the 100 MHz (G_CLKIN) as a reference. • Display PLL A PLL (82915G/92915GV/82915GL/82910GL GMCH Only) – This PLL generates the internal clocks for Display A. It uses D_REFCLKIN as a reference. • Display PLL B (82915G/92915GV/82915GL/82910GL GMCH Only) – This PLL generates the internal clocks for Display B. It uses D_REFCLKIN as a reference. Figure 12-3 illustrates the various clocks in the platform. Datasheet 253 Functional Description R Figure 12-3. System Clocking Example Diff Pair ITP CK410 56Pin SSOP Processor Diff Pair Processor Diff Pair Processor Diff Pair Processor Memory Slot 0 Slot 1 Slot 2 Main PLL SSC PCI Express GFX HPLL PCI Express Diff Pair PCI Express Diff Pair PCI Express Dif f Pair PCI Express Dif f Pair PCI Express Dev PCI Express Dev PCI Express Dev PCI Express Dev MPLL x16 PCI Exp DPLL DPLL (G)MCH P CI Express PLL DMI SATA PLL SSC PCI Express Dif f Pair PCI Express Dif f Pair PCI Express Dif f Pair SATA DiffPair 25 MHz Diff Pair 66 MHz Diff Pair 4 x1 PCI Exp SATA PLL P CI Express PLL CK410 48Pin SSOP 96 MHz DOT Diff Pair 48 MHz USB REF 14 MHz REF 14 MHz USB PLL SIO LPC LAN AC97 TPM LPC OSC FWH LPC GlueChip Port80 PCI LCI Bit Clock High Def Audio Bit Clock 48/14 MHz PLL 25 MHz REF 14 MHz PCI 33 MHz PCI 33 MHz PCI 33 MHz PCI 33 MHz PCI 33 MHz PCI 33 MHz PCI 33 MHz PCI 33 MHz PCI 33 MHz PCI 33 MHz PCI 33 MHz PCI 33 MHz Intel ® ICH6 66/33 Buffer 24 MHz Bit Clock 32.768 KHz High Def Audio PCI Slot PCI Slot PCI Slot PCI Slot 66 MHz 14.000 MHz § 254 PCI Slot PCI Slot 25 MHz Oscillator 66 MHz 66 MHz Datasheet Slot 3 Electrical Characteristics R 13 Electrical Characteristics This chapter contains the (G)MCH absolute maximum electrical ratings, power dissipation values, and DC characteristics. 13.1 Absolute Maximum Ratings Table 13-1 lists the (G)MCH’s maximum environmental stress ratings. Functional operation at the absolute maximum and minimum is neither implied nor guaranteed. Functional operating parameters are listed in the DC characteristics tables. Warning: Stressing the device beyond the “Absolute Maximum Ratings” may cause permanent damage. These are stress ratings only. Operating beyond the “operating conditions” is not recommended and extended exposure beyond “operating conditions” may affect reliability. Table 13-1. Absolute Maximum Ratings Symbol Parameter Min Max Uni t °C Notes Tstorage (G)MCH Core VCC Storage Temperature -55 150 1 1.5 V Core Supply Voltage with respect to VSS -0.3 1.65 V Host Interface (533 MHz/800 MHz) VTT VCCA_HPLL 1.2 V System Bus Input Voltage with respect to VSS 1.5 V Host PLL Analog Supply Voltage with respect to VSS -0.3 -0.3 1.65 1.65 V V DDR Interface (333 MHz/400 MHz) VCCSM (DDR) VCCA_SMPLL (DDR) 2.6 V DDR System Memory Supply Voltage with respect to VSS 1.5 V System Memory PLL Analog Supply Voltage with respect to VSS -0.3 -0.3 4.0 1.65 V V DDR2 Interface (400 MHz/533 MHz) VCCSM (DDR2) VCCA_SMPLL (DDR2) 1.8 V DDR2 System Memory Supply Voltage with Respect to VSS 1.5 V System Memory PLL Analog Supply Voltage with respect to VSS -0.3 -0.3 4.0 1.65 V V Datasheet 255 Electrical Characteristics R Symbol ® Parameter Min Max Uni t Notes PCI Express*/Intel SDVO/DMI Interface VCC_EXP VCCA_EXPPLL 1.5 V PCI Express and DMI Supply Voltage with respect to VSS 1.5 V PCI Express PLL Analog Supply Voltage with respect to VSS ® -0.3 -0.3 1.65 1.65 V V RGB/CRT DAC Display Interface (8 bit) (Intel 82915G/82915GV/82910GL GMCH only) VCCA_DAC VCCA_DPLLA VCCA_DPLLB 2.5 V Display DAC Analog Supply Voltage with respect to VSS 1.5 V Display PLL A Analog Supply Voltage with respect to VSS 1.5 V Display PLL B Analog Supply Voltage with respect to VSS -0.3 -0.3 -0.3 2.65 1.65 1.65 V V V CMOS Interface VCC2 2.5 V CMOS Supply Voltage with respect to VSS -0.3 2.65 V NOTES: 1. Possible damage to the (G)MCH may occur if the (G)MCH temperature exceeds 150 °C. Intel does not guarantee functionality for parts that have exceeded temperatures above 150 °C due to specification violation. 256 Datasheet Electrical Characteristics R 13.2 Symbol IVTT IVCC IVCC IVCC_EXP IVCCA_DAC Power Characteristics Parameter 1.2 V System Bus Supply Bus Current 1.5 V Core Supply Current (Integrated) 1.5 V Core Supply Current (Discrete) 1.5 V PCI Express and DMI Supply Current 2.5 V Display DAC Analog Supply Current 2.5 V CMOS Supply Current 1.5 V PCI Express and DMI PLL Analog Supply Current 1.5 V Host PLL Supply Current 1.5 V Display PLL A and PLL B Supply Current Signal Names VTT VCC VCC VCC_EXP VCCA_DAC Min — — — — — Typ — — — — — Max 1.0 9.7 7.7 1.4 70 Unit A A A A mA Notes 1, 4 2,3,4 2,3,4 Table 13-2. Non-Memory Power Characteristics IVCC2 IVCCA_EXPPLL IVCCA_HPLL IVCCA_DPLLA IVCCA_DPLLB VCC2 VCCA_EXPPL L VCCA_HPLL VCCA_DPLLA VCCA_DPLLB — — — — — — — — 2 45 45 55 mA mA mA mA NOTES: 1. Estimate is only for max current coming through Chipset’s supply balls 2. Rail includes PLL current 3. Includes Worst case Leakage 4. Calculated for highest frequencies Datasheet 257 Electrical Characteristics R Table 13-3. DDR Power Characteristics Symbol IVCCSM (DDR) ISUS_VCCSM (DDR) ISMVREF (DDR) ISUS_SMVREF ITTRC (DDR) ISUS_TTRC (DDR) IVCCA_SMPLL (DDR) Parameter DDR System Memory Interface (2.6 V) Supply Current DDR System Memory Interface (2.6 V) Standby Supply Current DDR System Memory Interface Reference Voltage (1.3 V) Supply Current DDR System Memory Interface Reference Voltage (1.3 V) Standby Supply Current DDR System Memory Interface Resistor Compensation Voltage (2.6 V) Supply Current DDR System Memory Interface Resistor Compensation Voltage (2.6 V) Standby Supply Current System Memory PLL Analog (1.5 V) Supply Current Min — Max 4.1 Unit A Notes — 25 mA — 10 µA — — 10 42 µA mA — 0 µA — 60 mA Table 13-4. DDR2 Power Characteristics Symbol IVCCSM (DDR2) ISUS_VCCSM (DDR2) ISMVREF (DDR2) ISUS_SMVREF (DDR2) ITTRC (DDR2) ISUS_TTRC (DDR2) IVCCA_SMPLL (DDR2) Parameter DDR2 System Memory Interface (1.8 V) Supply Current DDR2 System Memory Interface (1.8 V) Standby Supply Current DDR2 System Memory Interface Reference Voltage (0.90 V) Supply Current DDR2 System Memory Interface Reference Voltage (0.90 V) Standby Supply Current DDR2 System Memory Interface Resister Compensation Voltage (1.8 V) Supply Current DDR2 System Memory Interface Resister Compensation Voltage (1.8 V) Standby Supply Current System Memory PLL Analog (1.5 V) Supply Current Min — Max 4.7 Unit A Notes — 25 mA — 10 µA — 10 µA — 32 mA — 0 µA — 60 mA 258 Datasheet Electrical Characteristics R 13.3 Signal Groups The signal description includes the type of buffer used for the particular signal: GTL+ Open Drain GTL+ interface signal. Refer to the GTL+ I/O Specification for complete details. The (G)MCH integrates most GTL+ termination resistors. DDR System memory (2.6 V CMOS buffers) DDR2 System memory (1.8 V CMOS buffers) PCI Express interface signals. These signals are compatible with PCI Express 1.0a signaling environment AC Specifications. The buffers are not 3.3 V tolerant. Analog signal interface Voltage reference signal 2.5 V Tolerant High Voltage CMOS buffers 2.6 V Tolerant Stub Series Termination Logic 1.8 V Tolerant Stub Series Termination Logic DDR DDR2 PCI Express/SDVO Analog Ref HVCMOS SSTL-2 SSTL-1.8 Table 13-5. Signal Groups Signal Group Signal Type Signals Notes Host Interface Signal Groups (a) GTL+ Input/Outputs HADS#, HBNR#, HBREQ0#, HDBSY#, HDRDY#, HDINV[3:0]#, HA[31:3]#, HADSTB[1:0]#, HD[63:0], HDSTBP[3:0]#, HDSTBN[3:0]#, HHIT#, HHITM#, HREQ[4:0]#, HLOCK# HBPRI#, HCPURST#, HDEFER#, HTRDY#, HRS[2:0]#, HDPWR#, HEDRDY# BSEL[2:0], HPCREQ# (b) GTL+ Common Clock Outputs GTL+ Asynchronous Input Analog Host I/F Ref & Comp. Signals (c) (d) HVREF, HSWING HRCOMP, HSCOMP PCI-Express Graphics and SDVO Interface Signal Groups (e) PCI Express/SDVO Input PCI Express Interface (82915G/82915P/82915PL (G)MCH only): EXP_RXN[15:0], EXP_RXP[15:0], SDVO Interface (82915G/82915GV/82915GL/82910GL GMCH only): SDVO_TVCLKIN#, SDVO_TVCLKIN, SDVOB_INT#, SDVOB_INT, SDVO_STALL#, SDVO_STALL, SDVOC_INT#, SDVOC_INT Datasheet 259 Electrical Characteristics R Signal Group (f) Signal Type Signals Notes PCI Express/SDVO Output PCI Express Interface (82915G/82915P/82915PL (G)MCH only): EXP_TXN(15:0), EXP_TXP(15:0) SDVO Interface (82915G/82915GV/82915GL/82910GL GMCH only): SDVOB_RED#, SDVOB_RED, SDVOB_GREEN#, SDVOB_GREEN, SDVOB_BLUE#, SDVOB_BLUE, SDVOB_CLK, SDVOB_CLK#, SDVOC_RED#/SDVOB_ALPHA#, SDVOC_RED/SDVOB_ALPHA, SDVOC_GREEN#, SDVOC_GREEN SDVOC_BLUE#, SDVOC_BLUE, SDVOC_CLK, SDVOC_CLK# EXP_COMP0 EXP_COMPI (g) Analog PCI Express / SDVO Interface Compensation Signals DDR Interface Signal Groups (h) SSTL- 2 DDR CMOS I/O (i) SSTL – 2 DDR CMOS Output SDQ_A[63:0], SDQ_B[63:0], SDQS_A[7:0], SDQS_B[7:0] SDM_A[7:0], SDM_B[7:0], SMA_A[13:0], SMA_B[13:0], SBS_A[1:0], SBS_B[1:0], SRAS_A#, SRAS_B#, SCAS_A#, SCAS_B#, SWE_A#, SWE_B# SCKE_A[3:0], SCKE_B[3:0], SCS_A[3:0]#, SCS_B[3:0]#, SCLK_A[5:0], SCLK_A[5:0]#, SCLK_B[5:0], SCLK_B[5:0]# SMVREF[1:0] (DDR) ® (j) DDR Reference Voltage DDR2 Interface Signal Groups (Intel 82915G/82915GV GMCH and 82915P MCH only) (k) SSTL – 1.8 DDR2 CMOS I/O (l) SSTL – 1.8 DDR2 CMOS Output SDQ_A[63:0]#, SDQ_B[63:0]#, SDQS_A[7:0], SDQS_A[7:0]#, SDQS_B[7:0]#, SDQS_B[7:0]# SDM_A[7:0], SDM_B[7:0], SMA[13:0], SMA_B[13:0], SBS_A[2:0], SBS_B[2:0], SRAS_A#, SRAS_B#, SCAS_A#, SCAS_B#, SWE_A#, SWE_B#, SODT_A[3:0], SODT_B[3:0], SCKE_A[3:0], SCKE_B[3:0], SCS_A[3:0]#, SCS_B[3:0]#, SCLK_A[5:0], SCLK_A[5:0]#, SCLK_B[5:0], SCLK_B[5:0]# SMVREF[1:0] (DDR2) (m) DDR2 Reference Voltage 260 Datasheet Electrical Characteristics R Signal Group Signal Type ® Signals Notes RGB/CRT DAC Display Signal Groups (Intel 82915G/82915GV/82915GL/82910GL GMCH only) Analog Current Outputs Analog/Ref DAC Miscellaneous CMOS Type RED, RED#, GREEN, GREEN#, BLUE, BLUE# REFSET Current Mode Reference pin. DC Spec. not required HSYNC, VSYNC Clocks, Reset, and Miscellaneous Signal Groups (n) (n1) (0) (p) HVCMOS Input Miscellaneous Inputs Low Voltage Diff. Clock Input HVCMOS I/O EXTTS# RSTIN#, PWROK HCLKN, HCLKP, DREFCLKP, DREFCLKN, GCLKP, GCLKN SDVO_CRTLCLK, SDVO_CTRLDATA, DDC_CLK, DDC_DATA I/O Buffer Supply Voltages (q) 1.2 V System Bus Input Supply Voltage 1.5 V SDVO, PCI Express Supply Voltages 2.6 V DDR Supply Voltage 1.8 V DDR2 Supply Voltage 1.5 V DDR PLL Analog Supply Voltage 1.5 V DDR2 PLL Analog Supply Voltage 1.5 V (G)MCH Core Supply Voltage 2.5 V CMOS Supply Voltage 2.5 V RGB/CRT DAC Display Analog Supply Voltage PLL Analog Supply Voltages VTT (r) VCC_EXP (s) (t) VCCSM (DDR) VCCSM (DDR2) (u) VCCA_SMPLL (DDR) (v) VCCA_SMPLL (DDR2) (w) VCC (x) (y) VCC2 VCCA_DAC (z) VCCA_HPLL, VCCA_EXPPLL, VCCA_DPLLA, VCCA_DPLLB Datasheet 261 Electrical Characteristics R 13.4 13.4.1 DC Characteristics General DC Characteristics Table 13-6. DC Characteristics3 Symbol Signal Group Parameter Min Nom Max Unit Notes I/O Buffer Supply Voltage (AC Noise not included) VCCSM (DDR) VCCSM (DDR2) VCCA_SMPLL (DDR) VCCA_SMPLL (DDR2) VCC_EXP VTT VCC VCC2 VCCA_DAC VCCA_HPLL, VCCA_EXPPLL, VCCA_DPLLA, VCCA_DPLLB (s) (t) (u) (v) (r) (q) (w) (x) (y) (z) DDR I/O Supply Voltage DDR2 I/O Supply Voltage DDR I/O PLL Analog Supply Voltage DDR2 I/O PLL Analog Supply Voltage SDVO, PCI-Express Supply Voltage System Bus Input Supply Voltage (G)MCH Core Supply Voltage CMOS Supply Voltage CRT Display DAC Supply Voltage Various PLL’S Analog Supply Voltages 2.5 1.7 1.425 1.425 1.425 1.09 1.425 2.375 2.375 1.425 2.6 1.8 1.5 1.5 1.5 1.2 1.5 2.5 2.5 1.5 2.7 1.9 1.575 1.575 1.575 1.26 1.575 2.625 2.625 1.575 V V V V V V V V V V Reference Voltages HVREF (d) Host Address, Data, and Common Clock Signal Reference Voltage Host Compensation Reference Voltage DDR Reference Voltage 2/3 x VTT1– 2% 2/3 x VTT 2/3 x VTT + 2% V HSWING SMVREF (DDR) (d) (j) 1/4 x VTT – 2% 0.50 x VCCSM(DDR) – 0.05 0.49 x VCCSM (DDR2) 1/4 x VTT 0.50 x VCCSM (DDR) 0.50 x VCCSM (DDR2) 1/4 x VTT + 2% 0.50 x VCCSM(DDR) + 0.05 0.51 x VCCSM (DDR2) V V SMVREF (DDR2) Host Interface VIL_H VIH_H (m) DDR2 Reference Voltage V (a, c) Host GTL+ Input Low Voltage (a, c) Host GTL+ Input High Voltage -0.10 (2/3 x VTT) + 0.1 0 VTT (2/3 x VTT) – 0.1 VTT + 0.1 V V 262 Datasheet Electrical Characteristics R Symbol VOL_H VOH_H IOL_H ILEAK_H CPAD CPCKG DDR Interface VIL(DC) (DDR) VIH(DC) (DDR) VIL(AC) (DDR) VIH(AC) (DDR) VOL (DDR) VOH (DDR) ILeak (DDR) CI/O (DDR) Signal Group Parameter Min — VTT – 0.1 — — 2 0.90 Nom — — — — — — Max (0.25 x VTT)+0.1 VTT VTTmax / (1-0.25)Rttmin 20 3.5 2.5 Unit V V mA µA pF pF Notes (a, b) Host GTL+ Output Low Voltage (a, b) Host GTL+ Output High Voltage (a, b) Host GTL+ Output Low Current (a, c) Host GTL+ Input Leakage Current (a, c) Host GTL+ Input Capacitance (a, c) Host GTL+ Input Capacitance (common clock) Rttmin = 54Ω VOL