82945GZ [INTEL]

DRAM Controller, 2G X 8, CMOS, 37.50 X 37.50 MM, FCBGA;
82945GZ
型号: 82945GZ
厂家: INTEL    INTEL
描述:

DRAM Controller, 2G X 8, CMOS, 37.50 X 37.50 MM, FCBGA

动态存储器 外围集成电路
文件: 总318页 (文件大小:1535K)
中文:  中文翻译
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Intel® 945G/945GZ/945GC/  
945P/945PL Express Chipset  
Family  
Datasheet  
- For the Intel® 82945G/82945GZ/82945GC Graphics and Memory  
Controller Hub (GMCH) and Intel® 82945P/82945PL Memory  
Controller Hub (MCH)  
June 2008  
Document Number: 307502-005  
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® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL 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.  
1Hyper-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/info/hyperthreading/ for more information including details on which processors support HT Technology.  
Intel and Pentium 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© 2005-2008, Intel Corporation  
2
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Contents  
1
Introduction .......................................................................................................................17  
1.1  
1.2  
1.3  
Terminology..........................................................................................................21  
Reference Documents..........................................................................................23  
(G)MCH Overview................................................................................................23  
1.3.1  
1.3.2  
1.3.3  
1.3.4  
Host Interface........................................................................................24  
System Memory Interface.....................................................................24  
Direct Media Interface (DMI).................................................................25  
PCI Express* Interface (Intel® 82945G/82945GC/82945P/82945PL  
(G)MCH Only).......................................................................................26  
1.4  
1.5  
Graphics (Intel® 82945G/82945GC/82945GZ GMCH Only)................................27  
Analog and SDVO Displays (Intel® 82945G/82945GC/82945GZ GMCH Only) ..29  
1.5.1  
1.5.2  
1.5.3  
System Interrupts..................................................................................29  
(G)MCH Clocking..................................................................................29  
Power Management..............................................................................30  
2
Signal Description .............................................................................................................31  
2.1  
2.2  
2.3  
2.4  
2.5  
Host Interface Signals ..........................................................................................33  
DDR2 DRAM Channel A Interface.......................................................................36  
DDR2 DRAM Channel B Interface.......................................................................37  
DDR2 DRAM Reference and Compensation.......................................................38  
PCI Express* Interface Signals (Intel® 82945G/82945GC/82945P/82945PL  
Only).....................................................................................................................38  
2.6  
2.7  
2.8  
2.9  
Analog Display Signals (Intel® 82945G/82945GC/ 82945GZ GMCH Only) .......39  
Clocks, Reset, and Miscellaneous .......................................................................40  
Direct Media Interface (DMI) ................................................................................41  
Intel® Serial DVO (SDVO) Interface (Intel® 82945G/82945GC/82945GZ GMCH  
Only).....................................................................................................................41  
2.10  
2.11  
Power and Ground ...............................................................................................43  
Reset States and Pull-up/Pull-downs...................................................................44  
3
Register Description..........................................................................................................49  
3.1  
3.2  
3.3  
Register Terminology ...........................................................................................50  
Platform Configuration..........................................................................................50  
Configuration Mechanisms...................................................................................53  
3.3.1  
3.3.2  
Standard PCI Configuration Mechanism ..............................................53  
PCI Express* Enhanced Configuration Mechanism (Intel®  
82945G/82945GC/82945P/82945PL (G)MCH Only) ...........................53  
3.4  
Routing Configuration Accesses..........................................................................55  
3.4.1  
3.4.2  
Internal Device Configuration Accesses...............................................56  
Bridge Related Configuration Accesses...............................................56  
3.4.2.1  
PCI Express* Configuration Accesses (Intel®  
82945G/82945GC/82945P/82945PL (G)MCH Only)..........56  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
3
3.4.2.2  
DMI Configuration Accesses...............................................57  
3.5  
I/O Mapped Registers ..........................................................................................57  
3.5.1  
3.5.2  
CONFIG_ADDRESS—Configuration Address Register ......................58  
CONFIG_DATA—Configuration Data Register....................................59  
4
Host Bridge/DRAM Controller Registers (D0:F0) .............................................................61  
4.1 Device 0 Configuration Register Details ..............................................................63  
4.1.1  
4.1.2  
4.1.3  
4.1.4  
4.1.5  
4.1.6  
4.1.7  
4.1.8  
4.1.9  
VID—Vendor Identification (D0:F0)......................................................63  
DID—Device Identification (D0:F0) ......................................................63  
PCICMD—PCI Command (D0:F0).......................................................64  
PCISTS—PCI Status (D0:F0)...............................................................65  
RID—Revision Identification (D0:F0)....................................................66  
CC—Class Code (D0:F0) .....................................................................66  
MLT—Master Latency Timer (D0:F0)...................................................67  
HDR—Header Type (D0:F0) ................................................................67  
SVID—Subsystem Vendor Identification (D0:F0).................................67  
4.1.10 SID—Subsystem Identification (D0:F0)................................................68  
4.1.11 CAPPTR—Capabilities Pointer (D0:F0) ...............................................68  
4.1.12 EPBAR—Egress Port Base Address (D0:F0) ......................................69  
4.1.13 MCHBAR—(G)MCH Memory Mapped Register Range Base Address  
(D0:F0)..................................................................................................70  
4.1.14 PCIEXBAR—PCI Express* Register Range Base Address (D0:F0)  
(Intel® 82945G/82945GC/82945P/82945PL (G)MCH Only).................71  
4.1.15 DMIBAR—Root Complex Register Range Base Address (D0:F0) ......73  
4.1.16 GGC—GMCH Graphics Control Register (D0:F0) (Intel®  
82945G/82945GC/82945GZ GMCH Only)..........................................74  
4.1.17 DEVEN—Device Enable (D0:F0) .........................................................75  
4.1.18 PAM0—Programmable Attribute Map 0 (D0:F0)..................................76  
4.1.19 PAM1—Programmable Attribute Map 1 (D0:F0)..................................77  
4.1.20 PAM2—Programmable Attribute Map 2 (D0:F0)..................................78  
4.1.21 PAM3—Programmable Attribute Map 3 (D0:F0)..................................79  
4.1.22 PAM4—Programmable Attribute Map 4 (D0:F0)..................................80  
4.1.23 PAM5—Programmable Attribute Map 5 (D0:F0)..................................81  
4.1.24 PAM6—Programmable Attribute Map 6 (D0:F0)..................................82  
4.1.25 LAC—Legacy Access Control (D0:F0).................................................83  
4.1.26 TOLUD—Top of Low Usable DRAM (D0:F0).......................................84  
4.1.27 SMRAM—System Management RAM Control (D0:F0)........................85  
4.1.28 ESMRAMC—Extended System Management RAM Control (D0:F0) ..86  
4.1.29 ERRSTS—Error Status (D0:F0) ...........................................................87  
4.1.30 ERRCMD—Error Command (D0:F0) ...................................................88  
4.1.31 SKPD—Scratchpad Data (D0:F0) ........................................................89  
4.1.32 CAPID0—Capability Identifier (D0:F0) .................................................89  
MCHBAR Register ...............................................................................................90  
4.2  
4.2.1  
4.2.2  
4.2.3  
4.2.4  
4.2.5  
4.2.6  
4.2.7  
4.2.8  
4.2.9  
C0DRB0—Channel A DRAM Rank Boundary Address 0 ....................91  
C0DRB1—Channel A DRAM Rank Boundary Address 1 ....................93  
C0DRB2—Channel A DRAM Rank Boundary Address 2 ....................93  
C0DRB3—Channel A DRAM Rank Boundary Address 3 ....................93  
C0DRA0—Channel A DRAM Rank 0,1 Attribute .................................94  
C0DRA2—Channel A DRAM Rank 2,3 Attribute .................................94  
C0DCLKDIS—Channel A DRAM Clock Disable ..................................95  
C0BNKARC—Channel A DRAM Bank Architecture ............................96  
C0DRT1—Channel A DRAM Timing Register .....................................97  
4.2.10 C0DRC0—Channel A DRAM Controller Mode 0 .................................98  
4
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
4.2.11 C0DRC1—Channel A DRAM Controller Mode 1 ...............................100  
4.2.12 C1DRB0—Channel B DRAM Rank Boundary Address 0 ..................100  
4.2.13 C1DRB1—Channel B DRAM Rank Boundary Address 1 ..................100  
4.2.14 C1DRB2—Channel B DRAM Rank Boundary Address 2 ..................100  
4.2.15 C1DRB3—Channel B DRAM Rank Boundary Address 3 ..................101  
4.2.16 C1DRA0—Channel B DRAM Rank 0,1 Attribute ...............................101  
4.2.17 C1DRA2—Channel B DRAM Rank 2,3 Attribute ...............................101  
4.2.18 C1DCLKDIS—Channel B DRAM Clock Disable ................................101  
4.2.19 C1BNKARC—Channel B Bank Architecture ......................................101  
4.2.20 C1DRT1—Channel B DRAM Timing Register 1 ................................102  
4.2.21 C1DRC0—Channel B DRAM Controller Mode 0 ...............................102  
4.2.22 C1DRC1—Channel B DRAM Controller Mode 1 ...............................102  
4.2.23 PMCFG—Power Management Configuration ....................................102  
4.2.24 PMSTS—Power Management Status ................................................103  
EPBAR Registers—Egress Port Register Summary .........................................104  
4.3  
4.3.1  
4.3.2  
4.3.3  
4.3.4  
4.3.5  
EPESD—EP Element Self Description...............................................105  
EPLE1D—EP Link Entry 1 Description ..............................................106  
EPLE1A—EP Link Entry 1 Address....................................................107  
EPLE2D—EP Link Entry 2 Description ..............................................107  
EPLE2A—EP Link Entry 2 Address....................................................108  
5
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL  
Only)................................................................................................................................109  
5.1  
Configuration Register Details (D1:F0) ..............................................................112  
5.1.1  
5.1.2  
5.1.3  
5.1.4  
5.1.5  
5.1.6  
5.1.7  
5.1.8  
5.1.9  
VID1—Vendor Identification (D1:F0)..................................................112  
DID1—Device Identification (D1:F0) ..................................................112  
PCICMD1—PCI Command (D1:F0)...................................................113  
PCISTS1—PCI Status (D1:F0)...........................................................115  
RID1—Revision Identification (D1:F0)................................................116  
CC1—Class Code (D1:F0) .................................................................116  
CL1—Cache Line Size (D1:F0)..........................................................117  
HDR1—Header Type (D1:F0) ............................................................117  
PBUSN1—Primary Bus Number (D1:F0)...........................................117  
5.1.10 SBUSN1—Secondary Bus Number (D1:F0) ......................................118  
5.1.11 SUBUSN1—Subordinate Bus Number (D1:F0) .................................118  
5.1.12 IOBASE1—I/O Base Address (D1:F0) ...............................................119  
5.1.13 IOLIMIT1—I/O Limit Address (D1:F0) ................................................119  
5.1.14 SSTS1—Secondary Status (D1:F0)...................................................120  
5.1.15 MBASE1—Memory Base Address (D1:F0)........................................121  
5.1.16 MLIMIT1—Memory Limit Address (D1:F0).........................................122  
5.1.17 PMBASE1—Prefetchable Memory Base Address (D1:F0)................123  
5.1.18 PMLIMIT1—Prefetchable Memory Limit Address (D1:F0).................124  
5.1.19 CAPPTR1—Capabilities Pointer (D1:F0) ...........................................124  
5.1.20 INTRLINE1—Interrupt Line (D1:F0) ...................................................125  
5.1.21 INTRPIN1—Interrupt Pin (D1:F0).......................................................125  
5.1.22 BCTRL1—Bridge Control (D1:F0)......................................................126  
5.1.23 PM_CAPID1—Power Management Capabilities (D1:F0) ..................128  
5.1.24 PM_CS1—Power Management Control/Status (D1:F0) ....................129  
5.1.25 SS_CAPID—Subsystem ID and Vendor ID Capabilities (D1:F0) ......130  
5.1.26 SS—Subsystem ID and Subsystem Vendor ID (D1:F0) ....................130  
5.1.27 MSI_CAPID—Message Signaled Interrupts Capability ID (D1:F0)....131  
5.1.28 MC—Message Control (D1:F0)..........................................................132  
5.1.29 MA—Message Address (D1:F0).........................................................133  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
5
5.1.30 MD—Message Data (D1:F0) ..............................................................133  
5.1.31 PEG_CAPL—PCI Express* Capability List (D1:F0)...........................134  
5.1.32 PEG_CAP—PCI Express* Capabilities (D1:F0).................................134  
5.1.33 DCAP—Device Capabilities (D1:F0) ..................................................135  
5.1.34 DCTL—Device Control (D1:F0)..........................................................136  
5.1.35 DSTS—Device Status (D1:F0) ...........................................................137  
5.1.36 LCAP—Link Capabilities (D1:F0) .......................................................138  
5.1.37 LCTL—Link Control (D1:F0)...............................................................139  
5.1.38 LSTS—Link Status (D1:F0) ................................................................140  
5.1.39 SLOTCAP—Slot Capabilities (D1:F0) ................................................141  
5.1.40 SLOTCTL—Slot Control (D1:F0)........................................................142  
5.1.41 SLOTSTS—Slot Status (D1:F0) .........................................................143  
5.1.42 RCTL—Root Control (D1:F0) .............................................................144  
5.1.43 RSTS—Root Status (D1:F0)...............................................................145  
5.1.44 PEG_LC—PCI Express* Legacy Control (D1:F0)..............................146  
5.1.45 VCECH—Virtual Channel Enhanced Capability Header (D1:F0) ......147  
5.1.46 PVCCAP1—Port VC Capability Register 1 (D1:F0)...........................147  
5.1.47 PVCCAP2—Port VC Capability Register 2 (D1:F0)...........................148  
5.1.48 PVCCTL—Port VC Control (D1:F0) ...................................................148  
5.1.49 VC0RCAP—VC0 Resource Capability (D1:F0) .................................149  
5.1.50 VC0RCTL—VC0 Resource Control (D1:F0) ......................................149  
5.1.51 VC0RSTS—VC0 Resource Status (D1:F0)........................................150  
5.1.52 VC1RCAP—VC1 Resource Capability (D1:F0) .................................150  
5.1.53 VC1RCTL—VC1 Resource Control (D1:F0) ......................................151  
5.1.54 VC1RSTS—VC1 Resource Status (D1:F0)........................................152  
5.1.55 RCLDECH—Root Complex Link Declaration Enhanced Capability  
Header (D1:F0)...................................................................................152  
5.1.56 ESD—Element Self Description (D1:F0)............................................153  
5.1.57 LE1D—Link Entry 1 Description (D1:F0)............................................154  
5.1.58 LE1A—Link Entry 1 Address (D1:F0).................................................154  
5.1.59 UESTS—Uncorrectable Error Status (D1:F0)....................................155  
5.1.60 UEMSK—Uncorrectable Error Mask (D1:F0).....................................156  
5.1.61 CESTS—Correctable Error Status (D1:F0)........................................157  
5.1.62 CEMSK—Correctable Error Mask (D1:F0).........................................158  
5.1.63 PEG_SSTS—PCI Express* Sequence Status (D1:F0)......................159  
6
Direct Media Interface (DMI) RCRB................................................................................161  
6.1  
DMI RCRB Configuration Register Details.........................................................162  
6.1.1  
6.1.2  
6.1.3  
6.1.4  
6.1.5  
6.1.6  
6.1.7  
6.1.8  
6.1.9  
DMIVCECH—DMI Virtual Channel Enhanced Capability Header .....162  
DMIPVCCAP1—DMI Port VC Capability Register 1..........................162  
DMIPVCCAP2—DMI Port VC Capability Register 2..........................163  
DMIPVCCTL—DMI Port VC Control ..................................................163  
DMIVC0RCAP—DMI VC0 Resource Capability ................................164  
DMIVC0RCTL—DMI VC0 Resource Control .....................................165  
DMIVC0RSTS—DMI VC0 Resource Status.......................................166  
DMIVC1RCAP—DMI VC1 Resource Capability ................................166  
DMIVC1RCTL—DMI VC1 Resource Control .....................................167  
6.1.10 DMIVC1RSTS—DMI VC1 Resource Status.......................................167  
6.1.11 DMILCAP—DMI Link Capabilities ......................................................168  
6.1.12 DMILCTL—DMI Link Control..............................................................168  
6.1.13 DMILSTS—DMI Link Status ...............................................................169  
6.1.14 DMIUESTS—DMI Uncorrectable Error Status ...................................170  
6.1.15 DMIUEMSK—DMI Uncorrectable Error Mask....................................171  
6
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
6.1.16 DMICESTS—DMI Correctable Error Status.......................................172  
7
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)173  
7.1  
Configuration Register Details (D2:F0) ..............................................................175  
7.1.1  
7.1.2  
7.1.3  
7.1.4  
7.1.5  
7.1.6  
7.1.7  
7.1.8  
7.1.9  
VID2—Vendor Identification (D2:F0)..................................................175  
DID2—Device Identification (D2:F0) ..................................................175  
PCICMD2—PCI Command (D2:F0)...................................................176  
PCISTS2—PCI Status (D2:F0)...........................................................177  
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) ............................................................179  
7.1.10 MMADR—Memory Mapped Range Address (D2:F0) ........................180  
7.1.11 IOBAR—I/O Base Address (D2:F0) ...................................................181  
7.1.12 GMADR—Graphics Memory Range Address (D2:F0).......................182  
7.1.13 GTTADR—Graphics Translation Table Range Address (D2:F0).......182  
7.1.14 SVID2—Subsystem Vendor Identification (D2:F0).............................183  
7.1.15 SID2—Subsystem Identification (D2:F0)............................................183  
7.1.16 ROMADR—Video BIOS ROM Base Address (D2:F0).......................183  
7.1.17 CAPPOINT—Capabilities Pointer (D2:F0) .........................................184  
7.1.18 INTRLINE—Interrupt Line (D2:F0) .....................................................184  
7.1.19 INTRPIN—Interrupt Pin (D2:F0).........................................................184  
7.1.20 MINGNT—Minimum Grant (D2:F0)....................................................185  
7.1.21 MAXLAT—Maximum Latency (D2:F0) ...............................................185  
7.1.22 MCAPPTR—Mirror of Device 0 Capability Pointer (D2:F0)  
(Mirrored_D0_34) ...............................................................................185  
7.1.23 MCAPID—Mirror of Device 0 Capability Identification (D2:F0)  
(Mirrored_D0_E0)...............................................................................185  
7.1.24 MGGC—Mirror of Device 0 GMCH Graphics Control (D2:F0)  
(Mirrored_D0_52) ...............................................................................186  
7.1.25 MDEVEN—Mirror of Device 0 Device Enable (D2:F0)  
(Mirrored_D0_54) ...............................................................................186  
7.1.26 BSM—Base of “Stolen” Memory (D2:F0) ...........................................186  
7.1.27 PMCAPID—Power Management Capabilities ID (D2:F0)..................187  
7.1.28 PMCAP—Power Management Capabilities (D2:F0)..........................187  
7.1.29 PMCS—Power Management Control/Status (D2:F0) ........................188  
7.1.30 SWSMI—Software SMI (D2:F0) .........................................................188  
7.1.31 ASLE—System Display Event Register (D2:F0) ................................189  
7.1.32 ASLS—ASL Storage (D2:F0) .............................................................189  
8
Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ  
GMCH Only)....................................................................................................................191  
8.1.1  
8.1.2  
8.1.3  
8.1.4  
8.1.5  
8.1.6  
8.1.7  
8.1.8  
8.1.9  
VID2—Vendor Identification (D2:F1)..................................................192  
DID2—Device Identification (D2:F1) ..................................................192  
PCICMD2—PCI Command (D2:F1)...................................................193  
PCISTS2—PCI Status (D2:F1)...........................................................194  
RID2—Revision Identification (D2:F1)................................................195  
CC—Class Code Register (D2:F1).....................................................195  
CLS—Cache Line Size (D2:F1)..........................................................196  
MLT2—Master Latency Timer (D2:F1)...............................................196  
HDR2—Header Type Register (D2:F1)..............................................196  
8.1.10 MMADR—Memory Mapped Range Address (D2:F1) ........................197  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
7
8.1.11 SVID2—Subsystem Vendor Identification (D2:F1).............................197  
8.1.12 SID2—Subsystem Identification (D2:F1)............................................197  
8.1.13 ROMADR—Video BIOS ROM Base Address (D2:F1).......................198  
8.1.14 CAPPOINT—Capabilities Pointer (D2:F1) .........................................198  
8.1.15 MINGNT—Minimum Grant Register (D2:F1)......................................198  
8.1.16 MAXLAT—Maximum Latency (D2:F1) ...............................................198  
8.1.17 MCAPPTR—Mirror of Device 0 Capability Pointer (D2:F1)  
(Mirrored_D0_34) ...............................................................................199  
8.1.18 MCAPID—Mirror of Device 0 Capability Identification (D2:F1)  
(Mirrored_D0_E0)...............................................................................199  
8.1.19 MGGC—Mirror of Device 0 GMCH Graphics Control (D2:F1)  
(Mirrored_D0_52) ...............................................................................199  
8.1.20 MDEVEN—Mirror of Device 0 Device Enable (D2:F1)  
(Mirrored_D0_54) ...............................................................................199  
8.1.21 BSM—Base of Stolen Memory Register (D2:F1) ...............................200  
8.1.22 PMCAPID—Power Management Capabilities ID (D2:F1)..................200  
8.1.23 PMCAP—Power Management Capabilities (D2:F1)..........................200  
8.1.24 PMCS—Power Management Control/Status (D2:F1) ........................201  
8.1.25 SWSMI—Software SMI (D2:F1) .........................................................201  
8.1.26 ASLS—ASL Storage (D2:F1) .............................................................202  
Device 2 – PCI I/O Registers .............................................................................203  
8.2  
8.2.1  
8.2.2  
MMIO Index—MMIO Address Register..............................................203  
MMIO Data—MMIO Data Register.....................................................203  
9
System Address Map......................................................................................................205  
9.1  
Legacy Address Range......................................................................................207  
9.1.1  
9.1.2  
9.1.3  
9.1.4  
9.1.5  
9.1.6  
DOS Range (0h – 9_FFFFh) ..............................................................208  
Legacy Video Area (A_0000h–B_FFFFh) ..........................................208  
Expansion Area (C_0000h–D_FFFFh)...............................................209  
Extended System BIOS Area (E_0000h–E_FFFFh)..........................210  
System BIOS Area (F_0000h–F_FFFFh)...........................................210  
Programmable Attribute Map (PAM) Memory Area Details................210  
9.2  
9.3  
Main Memory Address Range (1 MB to TOLUD) ..............................................211  
9.2.1  
9.2.2  
9.2.3  
ISA Hole (15 MB–16 MB) ...................................................................212  
TSEG ..................................................................................................212  
Pre-allocated Memory.........................................................................212  
PCI Memory Address Range (TOLUD – 4 GB) .................................................213  
9.3.1  
9.3.2  
9.3.3  
9.3.4  
9.3.5  
9.3.6  
APIC Configuration Space (FEC0_0000h–FECF_FFFFh).................214  
HSEG (FEDA_0000h–FEDB_FFFFh)................................................214  
FSB Interrupt Memory Space (FEE0_0000–FEEF_FFFF) ................214  
High BIOS Area ..................................................................................214  
PCI Express* Configuration Address Space ......................................214  
PCI Express* Graphics Attach (Intel®  
82945G/82945GC/82945P/82945PL GMCH Only)............................215  
AGP DRAM Graphics Aperture ..........................................................215  
Graphics Memory Address Ranges (Intel® 82945G/82945GC/82945GZ  
GMCH Only) .......................................................................................216  
9.3.7  
9.3.8  
9.4  
System Management Mode (SMM) ...................................................................216  
9.4.1  
9.4.2  
9.4.3  
9.4.4  
SMM Space Definition ........................................................................217  
SMM Space Restrictions ....................................................................217  
SMM Space Combinations .................................................................218  
SMM Control Combinations................................................................218  
8
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
9.4.5  
9.4.6  
9.4.7  
SMM Space Decode and Transaction Handling ................................219  
Processor WB Transaction to an Enabled SMM Address Space ......219  
SMM Access through GTT TLB (Intel® 82945G/82945GC/82945GZ  
GMCH Only) .......................................................................................219  
Memory Shadowing............................................................................219  
I/O Address Space..............................................................................220  
9.4.8  
9.4.9  
9.4.10 PCI Express* I/O Address Mapping ...................................................220  
9.4.11 (G)MCH Decode Rules and Cross-Bridge Address Mapping ............220  
9.4.12 Legacy VGA and I/O Range Decode Rules .......................................221  
10  
Functional Description ....................................................................................................223  
10.1  
Host Interface .....................................................................................................223  
10.1.1 FSB IOQ Depth...................................................................................223  
10.1.2 FSB OOQ Depth.................................................................................223  
10.1.3 FSB GTL+ Termination.......................................................................223  
10.1.4 FSB Dynamic Bus Inversion...............................................................223  
10.1.4.1 APIC Cluster Mode Support..............................................224  
System Memory Controller.................................................................................224  
10.2.1 System Memory Configuration Registers Overview...........................226  
10.2.2 DRAM Technologies and Organization ..............................................226  
10.2.2.1 Rules for Populating DIMM Slots ......................................228  
10.2.2.2 System Memory Supported Configurations ......................229  
10.2.2.3 Main Memory DRAM Address Translation and Decoding 229  
10.2.3 DRAM Clock Generation ....................................................................232  
10.2.4 Suspend to RAM and Resume ...........................................................232  
10.2.5 DDR2 On Die Termination..................................................................232  
PCI Express* (Intel® 82945G/82945GC/ 82945P/82945PL (G)MCH Only)......233  
10.3.1 Transaction Layer...............................................................................233  
10.3.2 Data Link Layer...................................................................................233  
10.3.3 Physical Layer.....................................................................................233  
Intel® Serial Digital Video Output (SDVO) (Intel® 82945G/82945GC/82945GZ  
GMCH Only).......................................................................................................234  
10.4.1 Intel® SDVO Capabilities.....................................................................234  
10.4.2 Intel® SDVO Modes ............................................................................235  
10.4.3 PCI Express* and Internal Graphics Simultaneous Operation (Intel®  
82945G/82945GC GMCH Only).........................................................236  
10.4.3.1 Standard PCI Express* Cards and Internal Graphics .......236  
10.4.3.2 ADD2+ Cards (Concurrent SDVO and PCI Express*)......236  
Integrated Graphics Device (Intel® 82945G/82945GC/82945GZ GMCH Only) 239  
10.5.1 3D Graphics Pipeline..........................................................................239  
10.5.2 3D Engine ...........................................................................................240  
10.5.3 4X Faster Setup Engine......................................................................241  
10.5.3.1 3D Primitives and Data Formats Support..........................241  
10.5.3.2 Pixel Accurate “Fast” Scissoring and Clipping Operation .241  
10.5.3.3 Depth Bias.........................................................................241  
10.5.3.4 Backface Culling................................................................242  
10.5.3.5 Scan Converter..................................................................242  
10.5.3.6 Pixel Rasterization Rules ..................................................242  
10.5.3.7 Pixel Pipeline.....................................................................242  
10.5.3.8 Texture Samplers ..............................................................242  
10.5.3.9 2D Functionality.................................................................242  
10.5.4 Texture Engine....................................................................................243  
10.2  
10.3  
10.4  
10.5  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
9
10.5.4.1 Perspective Correct Texture Support................................243  
10.5.4.2 Texture Formats and Storage ...........................................243  
10.5.4.3 Texture Decompression ....................................................243  
10.5.4.4 Texture ChromaKey ..........................................................243  
10.5.4.5 Anti-Aliasing.......................................................................243  
10.5.4.6 Texture Map Filtering ........................................................244  
10.5.4.7 Multiple Texture Composition............................................244  
10.5.4.8 Pixel Shader ......................................................................245  
10.5.4.9 Cube Map Textures...........................................................245  
10.5.4.10 4x4 Texture Filtering Includes Cube Maps........................245  
10.5.5 Raster Engine .....................................................................................245  
10.5.5.1 Texture Map Blending .......................................................245  
10.5.5.2 Combining Intrinsic and Specular Color Components ......246  
10.5.5.3 Color Shading Modes........................................................246  
10.5.5.4 Color Dithering...................................................................246  
10.5.5.5 Vertex and Per Pixel Fogging............................................246  
10.5.5.6 Alpha Blending (Frame Buffer)..........................................247  
10.5.5.7 Microsoft Direct X* API and SGI OpenGL* Logic Ops......247  
10.5.5.8 Color Buffer Formats: 8-, 16-, or 32-bits per Pixel  
(Destination Alpha)............................................................247  
10.5.5.9 Depth Buffer ......................................................................248  
10.5.5.10 Stencil Buffer .....................................................................248  
10.5.5.11 Projective Textures............................................................248  
10.5.6 2D Engine ...........................................................................................249  
10.5.6.1 GMCH VGA Registers.......................................................249  
10.5.6.2 Logical 128-bit Fixed BLT and 256 Fill Engine..................249  
10.5.7 Video Engine.......................................................................................250  
10.5.7.1 Hardware Motion Compensation.......................................250  
10.5.7.2 Sub-Picture Support..........................................................250  
10.5.8 Planes.................................................................................................250  
10.5.8.1 Cursor Plane......................................................................251  
10.5.8.2 Overlay Plane....................................................................251  
10.5.8.3 Advanced Deinterlacing and Dynamic Bob and Weave ...252  
10.5.9 Pipes...................................................................................................252  
10.5.9.1 Clock Generator Units (DPLL) ..........................................252  
Display Interfaces (Intel® 82945G/82945GC/82945GZ GMCH Only)................252  
10.6.1 Analog Display Port Characteristics ...................................................253  
10.6.1.1 Integrated RAMDAC..........................................................254  
10.6.1.2 Sync Signals......................................................................254  
10.6.1.3 VESA/VGA Mode ..............................................................254  
10.6.1.4 DDC (Display Data Channel) ............................................254  
10.6.2 Digital Display Interface......................................................................255  
10.6.2.1 Multiplexed Digital Display Channels – Intel® SDVOB and  
Intel® SDVOC ....................................................................255  
10.6  
10.6.3 Multiple Display Configurations ..........................................................257  
10.7  
10.8  
Power Management ...........................................................................................258  
Clocking..............................................................................................................258  
11  
Electrical Characteristics.................................................................................................261  
11.1  
Absolute Minimum and Maximum Ratings.........................................................261  
11.1.1 Power Characteristics.........................................................................263  
Signal Groups.....................................................................................................264  
11.2  
10  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
11.3  
DC Characteristics .............................................................................................267  
11.3.1 RGB/CRT DAC Display DC Characteristics (Intel®  
82945G/82945GC/82945GZ GMCH Only).........................................270  
12  
13  
Ballout and Package Information....................................................................................271  
12.1  
12.2  
12.3  
Ballout.................................................................................................................271  
Ballout Table.......................................................................................................275  
Package..............................................................................................................305  
Testability........................................................................................................................308  
13.1  
13.2  
13.3  
13.4  
13.5  
Complimentary Pins ...........................................................................................308  
XOR Test Mode Initialization..............................................................................309  
XOR Chain Definition .........................................................................................310  
XOR Chains........................................................................................................311  
PADs Excluded from XOR Mode(s)...................................................................318  
Figures  
Figure 1-1. Intel® 945G Express Chipset System Block Diagram Example.....................18  
Figure 1-2. Intel® 945GZ/82945GC Express Chipset System Block Diagram Example ..19  
Figure 1-3. Intel® 945P/945PL Express Chipset System Block Diagram Example..........20  
Figure 2-1. Signal Information Diagram............................................................................32  
Figure 3-1. Conceptual Chipset Platform PCI Configuration Diagram .............................51  
Figure 3-2. Register Organization.....................................................................................52  
Figure 3-3. Memory Map-to-PCI Express* Device Configuration Space..........................54  
Figure 3-4. Intel® 82945G/82945GC (G)MCH Configuration Cycle Flow Chart...............55  
Figure 4-1. Link Declaration Topology............................................................................104  
Figure 9-1. System Address Ranges..............................................................................207  
Figure 9-2. Microsoft MS-DOS* Legacy Address Range ...............................................208  
Figure 9-3. Main Memory Address Range......................................................................211  
Figure 9-4. PCI Memory Address Range........................................................................213  
Figure 10-1. System Memory Styles...............................................................................225  
Figure 10-2. SDVO Conceptual Block Diagram..............................................................235  
Figure 10-3. Concurrent SDVO / PCI Express* Non-Reversed Configurations.............237  
Figure 10-4. Concurrent SDVO / PCI Express* Reversed Configurations.....................237  
Figure 10-5. Concurrent SDVO / PCI Express* Signal Multiplexing...............................238  
Figure 10-6. Integrated 3D Graphics Pipeline ................................................................240  
Figure 10-7. System Clocking Example..........................................................................259  
Figure 12-1. Intel® 82945G GMCH Ballout Diagram (Top View – Columns 43–30) ......272  
Figure 12-2. Intel® 82945G GMCH Ballout Diagram (Top View – Columns 29–16) ......273  
Figure 12-3. Intel® 82945G GMCH Ballout Diagram (Top View – Columns 15–1) ........274  
Figure 12-4. (G)MCH Package Dimensions ...................................................................306  
Figure 13-1. XOR Test Mode Initialization Cycles..........................................................309  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
11  
Tables  
Table 4-1. Host Bridge/DRAM Controller Register Address Map (D0:F0) .......................61  
Table 4-2. MCHBAR Register Address Map ....................................................................90  
Table 4-3. Egress Port Register Address Map ...............................................................104  
Table 5-1. Host-PCI Express* Graphics Bridge Register Address Map (D1:F0) ...........109  
Table 6-1. DMI Register Address Map ...........................................................................161  
Table 7-1. Integrated Graphics Device Register Address Map (D2:F0).........................173  
Table 8-1. Device 2 Function 1 Register Address Map (D2:F1).....................................191  
Table 9-1. Expansion Area Memory Segments..............................................................209  
Table 9-2. Extended System BIOS Area Memory Segments.........................................210  
Table 9-3. System BIOS Area Memory Segments .........................................................210  
Table 9-4. Pre-Allocated Memory Example for 64-MB DRAM, 1-MB VGA and 1-MB  
TSEG ............................................................................................................................. 212  
Table 9-5. SMM Space ...................................................................................................218  
Table 9-6. SMM Control..................................................................................................218  
Table 10-1. Sample System Memory Organization with Interleaved Channels .............224  
Table 10-2. Sample System Memory Organization with Asymmetric Channels ............224  
Table 10-3. DDR2 DIMM Supported Configurations ......................................................229  
Table 10-4. DRAM Address Translation (Single Channel/Dual Asymmetric Mode) ......230  
Table 10-5. DRAM Address Translation (Dual Channel Interleaved Mode)...................231  
Table 10-6. Concurrent SDVO / PCI Express* Configuration Strap Controls ................236  
Table 10-7. Display Port Characteristics ........................................................................253  
Table 10-8. Analog Port Characteristics.........................................................................254  
Table 11-1. Absolute Minimum and Maximum Ratings..................................................262  
Table 11-2. Non Memory Power Characteristics............................................................263  
Table 11-3. DDR2 Power Characteristics.......................................................................263  
Table 11-4. Signal Groups..............................................................................................264  
Table 11-5. DC Characteristics.......................................................................................267  
Table 11-6. RGB/CRT DAC Display DC Characteristics: Functional Operating Range  
(VCCA_DAC = 2.5 V 5%) ......................................................................................270  
Table 12-1. Intel® 82945G//82945GZ/82945GC/82945P/82945PL (G)MCH Ballout Sorted  
by Signal Name........................................................................................................275  
Table 13-1. Complimentary Pins to Drive.......................................................................308  
Table 13-2. XOR Chain Outputs.....................................................................................310  
Table 13-3. XOR Chain 0................................................................................................311  
Table 13-4. XOR Chain 1................................................................................................312  
Table 13-5. XOR Chain 2................................................................................................313  
Table 13-6. XOR Chain 3................................................................................................313  
Table 13-7. XOR Chain 4................................................................................................314  
Table 13-8. XOR Chain 5................................................................................................314  
Table 13-9. XOR Chain 6................................................................................................315  
Table 13-10. XOR Chain 7..............................................................................................316  
Table 13-11. XOR Chain 8..............................................................................................316  
Table 13-12. XOR Chain 9..............................................................................................317  
Table 13-13. XOR Pad Exclusion List.............................................................................318  
12  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Revision History  
Rev  
-001  
-002  
-003  
-004  
-005  
Description  
Date  
Initial Release  
May 2005  
Added Intel® 82945PL specifications  
Added Intel® 82945GZ specifications  
Added Intel® 82945GC specifications  
Updated Intel® 82945GC specifications  
October 2005  
December 2005  
October 2006  
June 2008  
§
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
13  
14  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Intel® 82945G/82945GZ/82945GC/82945P  
/82945PL (G)MCH Features  
Processor Interface  
Integrated Graphics Device (82945G/GZ/GC only)  
Core frequency of 400 MHz  
1.6 GP/s pixel rate  
High-Quality 3D Setup and Render Engine  
High-Quality Texture Engine  
VLD/iDCT for enabling dual Intel® High  
Definition streams for MPEG playback  
3D Graphics Rendering Enhancements  
2D Graphics  
Video Overlay  
Multiple Overlay Functionality  
Analog Display Support (82945G/GZ/GC only)  
400 MHz Integrated 24-bit RAMDAC  
Up to 2048x1536 @ 75 Hz refresh  
Hardware Color Cursor Support  
.
.
Intel® CoreTM2 Duo, Intel® Celeron 400 Series,  
Intel® Pentium® 4 processor in the 90 nm process  
in the LGA775 Land Grid Array package or  
Intel® Pentium® D processor (supports 775-Land  
package)  
Intel® AtomTM 200 series and Intel AtomTM 300  
Series (82945GC only)  
Supports Pentium 4 processor FSB interrupt  
delivery  
533/800 MT/s (133/200 MHz) FSB  
1066 MT/s (266 MHz) FSB (82945G/P only)  
Supports Hyper-Threading Technology1  
(HT Technology)  
FSB Dynamic Bus Inversion (DBI)  
32-bit host bus addressing  
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  
4 GB maximum memory  
.
.
DDC2B Compliant Interface  
Digital Display Support (82945G/GZ/GC only)  
Two SDVO ports multiplexed with PCI Express  
graphics interface  
200 MHz dot clock on each 12-bit interface  
Can combine two channels to form one larger  
interface  
Flat panels up to 2048x1536 @ 60 Hz or digital  
CRT/HDTV at 1920x1080 @ 85Hz  
Dual independent display options with digital  
display (82945G only)  
Intel® Extended Desktop and Dual Display  
Zoom (82945G only)  
Intel® Dual Display Clone and Dual Display  
Twin  
Multiplexed digital display channels (Supported  
with ADD2 Card).  
Supports TMDS transmitters or TV-Out encoders  
ADD2/ADD2+ card uses PCI Express graphics  
x16 connector (ADD2+ support for 945G only)  
.
One or two 64-bit wide DDR2 SDRAM data  
channels  
DDR2 400, DDR2 533  
DDR2 667 (82945G/ GC/P only)  
Bandwidth up to 10.7 GB/s (DDR2 667) in dual-  
channel Interleaved mode.  
Non-ECC memory only  
256-Mb, 512-Mb and 1-Gb DDR2 technologies  
Only x8, x16, DDR2 devices with four banks and  
also supports eight bank, 1-Gbit DDR2 devices.  
Opportunistic refresh  
Up to 32 simultaneously open pages in dual-  
channel mode  
SPD (Serial Presence Detect) scheme for DIMM  
detection support  
Suspend-to-RAM support using CKE  
Supports configurations defined in the JEDEC  
DDR2 DIMM specification only  
DMI Interface  
.
.
A chip-to-chip connection interface to Intel®  
ICH7  
2 GB/s point-to-point DMI to ICH7 (1 GB/s each  
direction)  
100 MHz reference clock (shared with PCI  
Express graphics attach)  
32-bit downstream addressing  
Messaging and Error Handling  
Package  
PCI Express* Graphics Interface (82945G/GC/P/PL  
only)  
One x16 PCI Express port  
.
Compatible with the PCI Express Base  
Specification, Revision 1.0a  
Raw bit rate on data pins of 2.5 Gb/s resulting in  
a real bandwidth per pair of 250 MB/s  
34 mm × 34 mm, 1202 balls, non-grid pattern  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
15  
§
16  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Introduction  
1 Introduction  
The Intel® 945G/945GZ/945GC/945P/945PL Express chipsets are designed for use with the  
Intel® CoreTM2 Duo, Intel® Celeron 400 series, Intel® Pentium® D processor, Intel® Pentium® 4  
processor. Additionally, Intel® 945GC Express chipsets also support Intel® AtomTM Processor 200  
Series and Intel® AtomTM Processor 300 Series. Each chipset contains two components: GMCH  
(or MCH) for the host bridge and I/O Controller Hub 7 (ICH7) for the I/O subsystem. The  
82945G GMCH is part of the 945G Express chipset, 82945GZ GMCH is part of the 945GZ  
Express chipset, 82945GC GMCH is part of the 945GC Express chipset, 82945P MCH is part of  
the 945P Express chipset, and 82945PL MCH is part of the 945PL Express chipset. The ICH7 is  
the seventh generation I/O Controller Hub and provides a multitude of I/O related functions.  
Figure 1-1, Figure 1-2, and Figure 1-3 show example system block diagrams for the 945G,  
945GZ, 945GC and 945P/945PL Express chipsets.  
This document is the datasheet for the Intel® 82945G Graphics and Memory Controller Hub  
(GMCH), Intel® 82945GZ Graphics and Memory Controller Hub (GMCH), Intel® 82945GC  
Graphics and Memory Controller Hub (GMCH), Intel® 82945P Memory Controller Hub (MCH),  
and Intel® 82945PL 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 primary differences between the 82945G GMCH, 82945GZ GMCH, 92945GC GMCH,  
82945P MCH, and 82945PL are listed below:  
Intel®  
82945G  
Intel®  
82945GZ  
Intel®  
82945GC  
Intel®  
82945P  
Intel®  
82945PL  
Intel® AtomTM  
Processor 200  
and 300 Series  
No  
No  
Yes  
Yes  
No  
No  
No  
No  
Integrated  
Graphics Device  
(and associated  
SDVO and  
Yes  
Yes  
analog display  
ports)  
PCI Express  
Interface  
Yes  
No  
Yes  
Yes  
Yes  
FSB Frequency  
1066/800/533  
MHz  
800/533 MHz  
800/533 MHz  
1066/800/533  
MHz  
800/533  
MHz  
Memory Speed  
DDR2-  
DDR2-  
DDR2-  
DDR2-  
DDR2-  
667/533/400  
533/400  
667/533/400  
667/533/400  
533/400  
System Memory  
Maximum  
4 GB  
2 GB  
2 GB  
4 GB  
2 GB  
Note: Unless otherwise specified, the information in this document applies to Intel® 82945G Graphics  
and Memory Controller Hub (GMCH), Intel® 82945GZ Graphics and Memory Controller Hub  
(GMCH), Intel® 82945GC Graphics and Memory Controller Hub (MCH), Intel® 82945P Memory  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
17  
Introduction  
Controller Hub (MCH), and Intel® 82945PL Memory Controller Hub (MCH),. The term (G)MCH  
refers to both the 82945G/82945GZ/82945GC GMCHs and 82945P/82945PL MCHs.  
Note: Unless otherwise specified, ICH7 refers to the Intel® 82801GB ICH7 and 82801GR ICH7R I/O  
Controller Hub 7 components.  
Figure 1-1. Intel® 945G Express Chipset System Block Diagram Example  
Processor  
533/800/1066 MHz FSB  
Intel® 945G Express Chipset  
Analog  
Display  
VGA  
System Memory  
Add2 or  
Add2+  
Card  
Display  
Display  
Channel A  
Channel B  
Intel® 82945G GMCH  
DDR2  
SDVO  
OR  
DDR2  
PCI Express*  
x16 Graphics  
Graphics  
Card  
Display  
DMI Interface  
USB* 2.0  
8 ports, 480 Mb/s  
Power Management  
IDE  
Clock Generation  
LAN Connect  
4 SATA* Ports  
Intel® ICH7 Family  
AC '97/Intel® High  
Definition Audio  
CODECs  
System  
Management (TCO)  
SMBus 2.0/I2C  
PCI Express* x1  
Intel® PCI Express  
Gigabit Ethernet  
PCI Bus  
GPIO  
SPI BIOS  
LPC Interface  
Super I/O  
Other ASICs  
(Optional)  
TPM  
(Optional)  
Flash BIOS  
Sys_Blk_945G  
18  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Introduction  
Figure 1-2. Intel® 945GZ/82945GC Express Chipset System Block Diagram Example  
Processor  
82945GZ/82945GC = 533/ 800 MHz FSB  
Analog  
Display  
VGA  
System Memory  
ADD2 Card  
Display  
Display  
Channel A  
Channel B  
DDR2  
®
Intel 82945GZ/82945GC  
GMCH  
SDVO  
®
DDR2  
Intel 82945GC GMCH ONLY  
PCI Express*  
x16 Graphics  
Graphics  
Display  
Card  
DMI Interface  
USB*2.0  
8 ports, 480Mb/s  
Power Management  
Clock Generation  
LAN Connect  
IDE  
4 SATA* Ports  
Intel® ICH7 Family  
®
System  
AC'97/Intel High  
Management(TCO)  
Definition Audio  
CODECs  
SMBus2.0/I2C  
PCI Express*x1  
GPIO  
®
Intel PCI Express  
PCI Bus  
Gigabit Ethernet  
SPI BIOS  
LPC Interface  
Super I/O  
Other ASICs  
( Optional)  
TPM  
( Optiona)l  
Flash BIOS  
Sys_Blk_945G  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
19  
Introduction  
Figure 1-3. Intel® 945P/945PL Express Chipset System Block Diagram Example  
Processor  
82945P MCH: 533/800/1066 MHz FSB  
82945PL MCH: 533/800 MHz FSB  
Intel® 945P/945PL  
Express Chipset  
System Memory  
DDR2  
Intel® 82945P/82945PL  
MCH  
Channel A  
Channel B  
PCI Express*  
x16 Graphics  
Graphics  
Card  
Display  
DDR2  
DMI Interface  
USB* 2.0  
8 ports, 480 Mb/s  
Power Management  
IDE  
Clock Generation  
LAN Connect  
4 SATA* Ports  
Intel® ICH7 Family  
AC '97/Intel® High  
Definition Audio  
CODECs  
System  
Management (TCO)  
SMBus 2.0/I2C  
PCI Express* x1  
Intel® PCI Express  
Gigabit Ethernet  
PCI Bus  
GPIO  
SPI BIOS  
LPC Interface  
Super I/O  
Other ASICs  
(Optional)  
TPM  
(Optional)  
Flash BIOS  
Sys_Blk_945P-and-945PL  
20  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Introduction  
1.1  
Terminology  
Term  
Description  
Accelerated  
Graphics Port  
(AGP)  
Refers to the AGP/PCI interface that was previously in the (G)MCH. It has been  
replaced by PCI Express*.  
ADD Card  
AGP Digital Display Card. It provides digital display options for an Intel Graphics  
Controller that supports ADD cards (DVOs multiplexed with AGP interface). It is keyed  
like an AGP 4x card and plugs into an AGP connector. The AGP Digital Display Card  
will not work with an Intel graphics controller that implements Intel® SDVO.  
ADD2 Card  
Advanced Digital Display Card – 2nd Generation. This card provides digital display  
options for an Intel graphics controller that supports ADD2 cards. It plugs into a x16 PCI  
Express* connector but uses the multiplexed SDVO interface. This Advanced Digital  
Display Card will not work with an Intel graphics controller that supports Intel® DVO and  
ADD cards.  
ADD2+ Card  
Advanced Digital Display Card – 2nd Generation. This card provides digital display  
options for an Intel graphics controller that supports ADD2+ cards. It plugs into a x16  
PCI Express connector but uses the multiplexed SDVO interface. The card adds Video  
In capabilities to the platform. This Advanced Digital Display Card will not work with an  
Intel graphics controller that supports DVO and ADD cards. It will function as an ADD2  
card in an ADD2 supported system, but Video In capabilities will not work. This is only  
supported on the Intel® 82945G GMCH.  
Core  
CRT  
DBI  
The internal base logic in the (G)MCH  
Cathode Ray Tube  
Dynamic Bus Inversion  
DDR  
DDR2  
DMI  
Double Data Rate SDRAM memory technology  
A second generation Double Data Rate SDRAM memory technology  
(G)MCH-Intel® ICH7 Direct Media Interface  
DVI  
Digital Video Interface. DVI is a specification that defines the connector and interface  
for digital displays.  
FSB  
Front Side Bus. FSB is synonymous with Host or processor bus  
Full Reset  
Full reset is when PWROK is de-asserted. Warm reset is when both RSTIN# and  
PWROK are asserted.  
GMCH  
Graphics Memory Controller Hub component that contains the processor interface,  
DRAM controller, x16 PCI Express port (typically, the external graphics interface), and  
an Integrated Graphics Device (IGD). The GMCH communicates with the I/O Controller  
Hub 7 (ICH7*) and other I/O controller hubs over the DMI interconnect. In this  
document GMCH refers to the Intel 82945G GMCH and/or 82945GZ GMCH  
components.  
HDMI  
High Definition Multimedia Interface. HDMI supports standard, enhanced, or high-  
definition video, plus multi-channel digital audio on a single cable. HDMI transmits all  
ATSC HDTV standards and supports 8-channel digital audio, with bandwidth to spare  
for future requirements and enhancements (additional details available through:  
http://www.hdmi.org/)  
Host  
INTx  
This term is used synonymously with processor.  
An interrupt request signal where “x” stands for interrupts A, B, C, and D  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
21  
Introduction  
Term  
Description  
Intel® DVO  
Digital Video Out port. This term is used for the first generation of Intel graphics  
controller’s digital display channels. Digital display data is provided in a parallel format.  
This interface is not electrically compatible with the 2nd generation digital display  
channel discussed in this document – SDVO.  
Intel® ICH7  
Seventh generation I/O Controller Hub component that contains additional functionality  
compared to previous ICHs. The I/O Controller Hub 7 component contains the primary  
PCI interface, LPC interface, USB2, ATA-100, and other I/O functions. ICH7  
communicates with the (G)MCH over a proprietary interconnect called DMI.  
IGD  
Internal Graphics Device.  
Liquid Crystal Display.  
LCD  
LVDS  
Low Voltage Differential Signaling. LVDS is a high speed, low power data transmission  
standard used for display connections to LCD panels.  
MCH  
Memory Controller Hub. The MCH contains the processor interface, DRAM controller,  
and x16 PCI Express port (typically, the external graphics interface). It communicates  
with the I/O Controller Hub 7 (ICH7) and other I/O controller hubs over the DMI  
interconnect. In this document MCH refers to the Intel 82945P MCH and/or 82945PL  
MCH components.  
MSI  
Message Signaled Interrupt. MSI is a transaction initiated outside the host, conveying  
interrupt information to the receiving agent through the same path that normally carries  
read and write commands.  
PCI Express*  
Third Generation input/output graphics attach called PCI Express Graphics. PCI  
Express is a high-speed serial interface. The PCI Express configuration is software  
compatible with the existing PCI specifications. The specific PCI Express  
implementation intended for connecting the (G)MCH to an external Graphics Controller  
is a x16 link and replaces AGP.  
Primary PCI  
The Primary PCI is the physical PCI bus that is driven directly by the ICH7 component.  
Communication between Primary PCI and the (G)MCH occurs over DMI. Note that the  
Primary PCI bus is not PCI Bus 0 from a configuration standpoint.  
Processor  
SCI  
Intel® Pentium® D processor and Intel® Pentium® 4 processor  
System Control Interrupt. SCI is used in ACPI protocol.  
SDVO  
Serial Digital Video Out (SDVO). SDVO is a 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 82945G/82945GZ GMCH, the SDVO  
interface is multiplexed on a portion of the x16 graphics PCI Express interface.  
SDVO Device  
SERR  
Third party codec that uses SDVO as an input. May have a variety of output formats,  
including DVI, LVDS, HDMI, TV-Out, etc.  
System Error. SERR is an indication that an unrecoverable error has occurred on an  
I/O bus.  
SMI  
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).  
Rank  
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.  
TMDS  
Transition Minimized Differential Signaling. TMDS is a signaling interface from Silicon  
Image that is used in DVI and HDMI.  
22  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Introduction  
Term  
TOLM  
Description  
Top Of Low Memory. The highest address below 4 GB where a processor-initiated  
memory read or write transaction will create a corresponding cycle to DRAM on the  
memory interface.  
VCO  
UMA  
Voltage Controlled Oscillator  
Unified Memory Architecture. UMA describes an IGD using system memory for its  
frame buffers.  
1.2  
Reference Documents  
Document Name  
Doc Number/Location  
Intel® I/O Controller Hub 7 (ICH7) Family Datasheet  
http://developer.intel.com//design/ch  
ipsets/datashts/307013.htm  
Intel® 945G/945GZ/82945GC/945P/945PL Express Chipset Family  
Thermal and Mechanical Design Guidelines  
http://developer.intel.com/design/chi  
psets/designex/307504.htm  
Intel® 945G/945GZ/82945GC/945P/945PL Express Chipset Family  
Specification Update  
http://developer.intel.com/design/chi  
psets/specupdt/307503.htm  
Advanced Configuration and Power Interface Specification,  
Revision 2.0  
http://www.acpi.info/  
Advanced Configuration and Power Interface Specification,  
Revision 1.0b  
http://www.acpi.info/  
The PCI Local Bus Specification, Revision 2.3  
http://www.pcisig.com/specifications  
http://www.pcisig.com/specifications  
PCI Express* Specification, Revision 1.0a, July 22, 2002  
1.3  
(G)MCH Overview  
The (G)MCH connects to the processor as shown in the previous system block diagrams. The  
primary role of a (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 (82945G/82945GZ/82945GC GMCH only), the external graphics  
interface (PCI Express), and the I/O Controller through DMI interface. This includes arbitrating  
between the four interfaces when each initiates transactions.  
The (G)MCH supports one or two channels of DDR2 SDRAM. The (G)MCH also supports the  
new PCI Express based external graphics attach. To increase system performance, the (G)MCH  
incorporates several queues and a write cache. The (G)MCH also contains advanced desktop  
power management logic.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
23  
Introduction  
1.3.1  
Host Interface  
The (G)MCH is optimized for the Intel® AtomTM 200 Series, Intel® AtomTM 300 Series based on  
45nm process technology in a FCBGA 437 pins socket, Intel® CoreTM 2 Duo, Intel® Celeron 400  
series, Intel® Pentium 4 processor in the 90 nm process in the LGA775 Land Grid Array package  
and Intel® Pentium D processor in a LGA775 socket; Only the 82945GC (G)MCH are designed  
for use with Intel® AtomTM 200 Series and Intel® AtomTM 300 Series. The (G)MCH supports FSB  
frequencies using a scalable FSB Vcc_CPU. FSB frequencies supported are 133 MHz  
(533 MT/s), 200 MHz (800 MT/s), and 266 MHz (1066 MT/s); only the 82945G/82945P  
(G)MCH support 266 MHz (1066 MT/s).  
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 (2x) address and source synchronous quad-pumped (4x) data. Other  
(G)MCH supported features of the host interface include: Hyper-Threading Technology (HT  
Technology), Pentium 4 processor FSB interrupt delivery, FSB Dynamic Bus Inversion (DBI),  
12-deep in-order queue, and a 1-deep defer queue.  
The (G)MCH supports 32-bit host addressing, decoding up to 4 GB (2 GB for the  
82945PL/82945GC/82945GZ) of the processor’s usable memory address space. Host-initiated I/O  
cycles are decoded to PCI Express, DMI, or the (G)MCH configuration space. Host-initiated  
memory cycles are decoded to PCI Express, DMI or main 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 SDRAM will be snooped on the  
host bus.  
1.3.2  
System Memory Interface  
The (G)MCH integrates a system memory DDR2 controller with two, 64-bit wide interfaces.  
Only Double Data Rate (DDR2) memory is supported; consequently, the buffers support only  
SSTL_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:  
Maximum memory size:  
4 GB for 82945G GMCH and 82945P MCH  
2 GB for 82945GZ/82945GC GMCH and 82945PL MCH  
Directly supports one or two channels of memory (each channel consisting of 64 data lines)  
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).  
Supports DDR2 400, DDR2 533, and DDR2 667. DDR2 667 is supported on  
82945G/82945GC/82945P Only.  
Available bandwidth up to 5.3 GB/s (DDR2 667) for single-channel mode or dual-channel  
asymmetric mode and 10.7 GB/s (DDR2 667) in dual-channel Interleaved mode.  
Supports DDR2 memory DIMM frequencies of 400 MHz, 533 MHz, and  
667 MHz (82945G/82945GC/82945P Only). The speed used in all channels is the speed of  
the slowest DIMM in the system.  
Supports 256-Mb, 512-Mb, and 1-Gb DDR2 technologies for x8 and x16 devices.  
24  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Introduction  
Supports four banks for all DDR2 devices up to 512-Mbit density. Supports eight banks for  
1-Gbit DDR2 devices.  
DDR2-667 4-4-4 is Not supported.  
Supports only unbuffered DIMMs.  
Supports opportunistic refresh.  
In dual channel mode the (G)MCH supports 32 simultaneously open pages.  
SPD (Serial Presence Detect) scheme for DIMM detection support.  
Suspend-to-RAM support using CKE.  
Supports configurations defined in the JEDEC DDR2 DIMM specification only.  
Directly supports two channels of non-ECC DDR2 DIMMs.  
Supports Partial Writes to memory using Data Mask (DM) signals.  
Supports a burst length of 8 for single-channel and dual-channel interleaved and asymmetric  
operating modes.  
Supports Enhanced Memory Interleave.  
1.3.3  
Direct Media Interface (DMI)  
Direct Media Interface (DMI) is the chip-to-chip connection between the (G)MCH and I/O  
Controller Hub 7 (ICH7). 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 ICH7 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 ICH7 and (G)MCH).  
Configuration registers for DMI, virtual channel support, and DMI active state power  
management (ASPM) are in the RCRB space in the (G)MCH Register Description.  
A chip-to-chip connection interface to the ICH7  
2 GB/s point-to-point DMI to ICH7 (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  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
25  
Introduction  
1.3.4  
PCI Express* Interface (Intel®  
82945G/82945GC/82945P/82945PL (G)MCH Only)  
The 82945G/82945GC/82945P/82945PL (G)MCH contains one 16-lane (x16) PCI Express port  
intended for an external PCI Express graphics card. The PCI Express port is compliant to 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 82945G GMCH multiplexes the PCI Express interface with two Intel®  
SDVO ports.  
One, 16-lane PCI Express port intended for Graphics Attach, compatible to the PCI Express*  
Base Specification, Revision 1.0a.  
A base PCI Express frequency of 2.5 Gb/s only.  
Raw bit-rate on the data pins of 2.5 Gb/s, resulting in a real 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 x16.  
PCI Express extended configuration space. The first 256 bytes of configuration space is  
aliased directly to the PCI Compatibility configuration space. The remaining portion of the  
fixed 4-KB block of memory-mapped space above the first 256 bytes (starting at 100h) is  
known as extended configuration space.  
PCI Express Enhanced Addressing Mechanism. This mechanism accesses 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.  
26  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Introduction  
1.4  
Graphics (Intel® 82945G/82945GC/82945GZ GMCH  
Only)  
The 82945G/82945GC/82945GZ 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 (PEG) port but cannot work concurrently with  
the integrated graphics device. 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). The 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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
27  
Introduction  
GMCH graphics support includes:  
3D Graphics Rendering Enhancements  
Core Frequency of 400 MHz  
1.6 GP/s pixel rate  
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  
Serial DVO port with two channels (multiplexed on  
PCI Express* Graphics port) for optional addition  
of TV-Out/TV-In and/or DVI digital display  
connections  
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 @ 85 Hz  
Fast Clear Support  
ADD2+ card support (Concurrent PCI  
Express with SDVO) (82945G only)  
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 OGL* pixelization rules  
Anti-aliased lines  
Sprite points  
Zone Rendering Technology 3  
Shadow maps  
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  
Double-sided stencil  
High-Quality Texture Engine  
DX9* Compliant Hardware Pixel Shader 2.0  
Per-pixel perspective corrected texture  
mapping  
Video DVD/PC-VCR  
2/10/10/10 texture format  
4x4 filtering  
Single-pass quad texture compositing  
Enhanced texture blending functions  
12 levels of detail mip map sizes from 1x1 to  
2Kx2K  
VLD/iDCT for enabling Dual HD Streams for  
MPEG playback (82945G only)  
H/W Motion Compensation for MPEG2  
- 4x HWMC computes  
Dynamic Bob and Weave Support for Video  
Streams  
Source Resolution up to 1920x1080 with 2  
vertical taps  
All texture formats including 32-bit RGBA  
and 8-bit palettes  
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  
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  
Video Overlay  
Advanced Deinterlacing  
Process Amplifier Color Control  
Single High Quality Scalable Overlay  
Render to texture  
Multiple Overlay Functionality provided via Stretch  
Blitter (PIP, Video Conferencing, etc.)  
Video DVD/PC-VCR  
VLD/iDCT for enabling Dual HD Streams for  
5-tap Horizontal, 3-tap Vertical Filtered Scaling  
Independent Gamma Correction  
Independent Brightness/Contrast/Saturation  
Independent Tint/Hue Support  
Destination Color-keying  
MPEG playback (82945G only)  
H/W Motion Compensation for MPEG2  
- 4x HWMC computes  
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 Use for PC-VCR or home  
movie recording and editing  
Source Chroma-keying  
Maximum Source Resolution: 720x480x32  
Maximum Overlay Display Resolution:  
2048x1536x32  
Video Mixer Render (VMR)  
28  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Introduction  
1.5  
Analog and SDVO Displays (Intel®  
82945G/82945GC/82945GZ GMCH Only)  
The GMCH provides interfaces to a progressive scan analog monitor and two SDVO ports  
(multiplexed with PCI Express x16 graphics port signals on the 82945G/82945GC) capable of  
driving an ADD2/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 ADD2+ card adds Video-in capabilities and is only supported on the 82945G  
GMCH. The GMCH provides two multiplexed SDVO ports that are capable of driving up to a  
200 MHz pixel clock each. The GMCH can make use of these digital display channels via an  
Advanced Digital Display card (ADD2/2+) card.  
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 be combined 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 82945G/82945GC GMCH supports Hot-Plug and Display for the PCI Express x16 graphics.  
This is not supported for ADD2 cards.  
1.5.1  
1.5.2  
System Interrupts  
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  
Provides redirection for IPI(Inter-Processor Interrupts) and upstream interrupts to the FSB  
(G)MCH Clocking  
The differential Host clock of 133/200/266 MHz (HCLKP/HCLKN) supports transfer rates of  
533/800/1066 MT/s, respectively. The 266 MHz HCLKP/HCLKN is only available on the  
82945G GMCH and 82945P MCH. 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 200, 266, and 333 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.  
The PCI Express core clock of 250 MHz is generated from a separate PCI Express PLL that uses  
the fixed 100 MHz Serial Reference Clock (GCLKP/GCLKN) for reference.  
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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
29  
Introduction  
All of the above clocks are capable of tolerating Spread Spectrum clocking as defined in the  
Clock Generator specification. Host, memory, and PCI Express PLLs, and all associated internal  
clocks are disabled until PWROK is asserted.  
1.5.3  
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 Revision 1.0 compatible power management  
Supports processor states C0 and C1. The (G)MCH does not support the C2, C3, and C4  
states.  
Supports system states S0, S1D, S3, S4, and S5  
Supports processor Thermal Management 2 (TM2)  
Microsoft Windows NT* Hardware Design Guide v1.0 compliant  
§
30  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Signal Description  
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 (see Figure 2-1).  
The following notations are used to describe the signal type:  
PCIE  
DMI  
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 Vmax. 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 Vmax. Single-ended maximum = 1.5 V. Single-ended minimum = 0 V.  
CMOS  
COD  
CMOS buffers. 1.5 V tolerant.  
CMOS Open Drain buffers. 2.5 V tolerant.  
HCSL  
Host Clock Signal Level buffers. Current mode differential pair. Differential  
typical swing = (|D+ - D-|) * 2 = 1.4 V. Single ended input tolerant from -0.35 V  
to 1.2 V. Typical crossing voltage is 0.35 V.  
HVCMOS  
HVIN  
High Voltage CMOS buffers. 2.5 V tolerant.  
High Voltage CMOS input-only buffers. 3.3 V tolerant.  
SSTL-1.8  
Stub Series Termination Logic. These are 1.8 V output capable buffers. 1.8 V  
tolerant.  
A
Analog reference or output. May be used as a threshold voltage or for buffer  
compensation.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
31  
Signal Description  
Figure 2-1. Signal Information Diagram  
Intel®  
82945G/  
82945GZ/  
82945GC  
GMCH  
HA[31:3]#  
HD[63:0]  
HADS#  
HSYNC  
VSYNC  
RED, RED#  
GREEN, GREEN#  
BLUE, BLUE#  
REFSET  
DDC_CLK  
DDC_DATA  
HBNR#  
Analog  
Display  
HBPRI#  
HDBSY#  
HDEFER#  
HDRDY#  
HEDRDY#  
HHIT#  
Only  
SDVOB_GREEN-, SDVOB_GREEN+  
SDVOB_BLUE-, SDVOB_BLUE+  
SDVOB_RED-, SDVOB_RED+  
SDVOB_CLK-, SDVOB_CLK+  
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  
HHITM#  
HLOCK#  
HREQ[4:0]#  
HPCREQ#  
HTRDY#  
HRS[2:0]#  
HCPURST#  
HBREQ0#  
Processor  
System  
Bus  
Intel®  
SDVO  
Intel®  
82945G/  
82945GZ/  
82945GC  
GMCH  
Interface  
Device  
Interface1  
HDINV[3:0]#  
HADSTB[1:0]#  
HDSTBP[3:0]#, HDSTBN[3:0]#  
BSEL[2:0]  
Only  
HRCOMP  
HSCOMP  
HSWING  
SDVO_CTRLDATA  
Intel®  
82945G/  
82945GC  
GMCH  
and  
82945P/  
82945PL  
MCH  
HDVREF  
HACCVREF  
PCI  
Express*  
x16  
Graphics  
Port  
EXP_RXN[15:0], EXP_RXP[15:0]  
EXP_TXN[15:0], EXP_TXP[15:0]  
EXP_COMPO  
SCS_A[3:0]#  
SMA_A[13:0]  
SBS_A[2:0]  
SRAS_A#  
SCAS_A#  
EXP_COMPI  
System  
Memory  
SWE_A#  
SDQ_A[63:0]  
DDR2  
Channel  
A
HCLKP, HCLKN  
GCLKP, GCLKN  
DREFCLKN, DREFCLKP  
RSTIN#  
PWROK  
EXTTS#  
Only  
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]  
Clocks,  
Reset, and  
Misc.  
EXP_EN  
EXP_SLR  
ICH_SYNC#  
XORTEST  
SCS_B[3:0]#  
SMA_B[13:0]  
SBS_B[2:0]  
SRAS_B#  
SCAS_B#  
System  
Memory  
ALLZTEST  
Direct  
Media  
Interface  
SWE_B#  
SDQ_B[63:0]  
SDM_B[7:0]  
SDQS_B[7:0], SDQS_B[7:0]#  
SCKE_B[3:0]  
DMI_RXP[3:0], DMI_RXN[3:0]  
DMI_TXP[3:0], DMI_TXN[3:0]  
DDR2  
Channel  
B
VCC  
VTT  
VCC_EXP  
VCCSM  
VCC2  
VCCA_EXPPLL  
VCCA_DPLLA  
VCCA_DPLLB  
VCCA_HPLL  
VCCA_SMPLL  
VSS  
SCLK_B[5:0], SCLK_B[5:0]#  
SODT_B[3:0]  
Voltage  
Reference,  
and Power  
SRCOMP[1:0]  
SOCOMP[1:0]  
SMVREF[1:0]  
System  
Memory  
DDR2 Ref./  
Comp.  
VCCA_DAC  
VSSA_DAC  
Note:  
1. SDVO signals on the 82945G GMCH are multiplexed with the PCI Express x16 Graphics Port signals.  
Signal_Info  
32  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Signal Description  
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  
Type  
Description  
HADS#  
I/O  
GTL+  
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.  
HBNR#  
HBPRI#  
I/O  
GTL+  
Block Next Request: HBNR# 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.  
O
GTL+  
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.  
HBREQ0#  
I/O  
GTL+  
Bus Request 0: The (G)MCH pulls the processor’s bus HBREQ0# signal  
low during HCPURST#. The processor samples this signal on the active-to-  
inactive transition of HCPURST#. The minimum setup time for this signal is  
4 HCLKs. The minimum hold time is 2 HCLKs and the maximum hold time  
is 20 HCLKs. HBREQ0# should be tristated after the hold time requirement  
has been satisfied.  
HCPURST#  
O
GTL+  
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® ICH7 must provide processor frequency select strap set-  
up and hold times around HCPURST#. This requires strict synchronization  
between (G)MCH HCPURST# de-assertion and the ICH7 driving the straps.  
HDBSY#  
I/O  
Data Bus Busy: This signal is used by the data bus owner to hold the data  
GTL+  
bus for transfers requiring more than one cycle.  
HDEFER#  
O
GTL+  
Defer: HDEFER# indicates that the (G)MCH will terminate the transaction  
currently being snooped with either a deferred response or with a retry  
response.  
HDINV[3:0]#  
I/O  
GTL+  
Dynamic Bus Inversion: These signals are driven along with the HD[63:0]  
signals. They indicate 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.  
HDINV[x]#  
HDINV3#  
HDINV2#  
HDINV1#  
HDINV0#  
Data Bits  
HD[63:48]  
HD[47:32]  
HD[31:16]  
HD[15:0]  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
33  
Signal Description  
Signal Name  
Type  
Description  
HDRDY#  
I/O  
Data Ready: This signal is asserted for each cycle that data is transferred.  
GTL+  
HEDRDY#  
HA[31:3]#  
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.  
I/O  
GTL+  
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* initiators.  
HA[31:3]# are transferred at 2x rate.  
HADSTB[1:0]#  
HD[63:0]  
I/O  
GTL+  
Host Address Strobe: These signals are the source synchronous strobes  
used to transfer HA[31:3]# and HREQ[4:0] at the 2x transfer rate.  
I/O  
GTL+  
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.  
HDSTBP[3:0]#  
HDSTBN[3:0]#  
I/O  
GTL+  
Differential Host Data Strobes: These signals are the differential source  
synchronous strobes 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  
Data  
Bits  
HDSTBP3#, HDSTBN3#  
HDSTBP2#, HDSTBN2#  
HDSTBP1#, HDSTBN1#  
HDSTBP0#, HDSTBN0#  
HD[63:48]  
HD[47:32]  
HD[31:16]  
HD[15:0]  
HDINV3#  
HDINV2#  
HDINV1#  
HDINV0#  
HHIT#  
I/O  
GTL+  
Hit: This signal indicates that a caching agent holds an unmodified version  
of the requested line. In addition, HHIT# is driven in conjunction with  
HHITM# by the target to extend the snoop window.  
HHITM#  
I/O  
GTL+  
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. In addition, HHITM# is driven in conjunction with HHIT#  
to extend the snoop window.  
HLOCK#  
I/O  
GTL+  
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 accesses to DRAM are allowed when HLOCK# is asserted by  
the processor).  
HPCREQ#  
I
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.  
HPCREQ# is asserted by the requesting agent during both halves of  
Request Phase. The same information is provided in both halves of the  
request phase.  
GTL+  
2x  
34  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Signal Description  
Signal Name  
Type  
Description  
HREQ[4:0]#  
I/O  
GTL+  
2x  
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.  
HTRDY#  
O
Host Target Ready: This signal indicates that the target of the processor  
GTL+  
transaction is able to enter the data transfer phase.  
HRS[2:0]#  
O
Response Signals: These signals indicate the type of response as shown  
GTL+  
below:  
000 = Idle state  
001 = Retry response  
010 = Deferred response  
011 = Reserved (not driven by (G)MCH)  
100 = Hard Failure (not driven by (G)MCH)  
101 = No data response  
110 = Implicit Writeback  
111 = Normal data response  
BSEL[2:0]  
HRCOMP  
HSCOMP  
HSWING  
I
Bus Speed Select: At the de-assertion of RSTIN#, the value sampled on  
these pins determines the expected frequency of the bus.  
CMOS  
I/O  
CMOS  
Host RCOMP: This signal is used to calibrate the Host GTL+ I/O buffers.  
This signal is powered by the Host Interface termination rail (VTT).  
I/O  
CMOS  
Slew Rate Compensation: This is the compensation signal for the Host  
Interface.  
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.  
HDVREF  
I
Host Reference Voltage: Voltage input for the data, address, and common  
A
clock signals of the Host GTL interface.  
HACCVREF  
I
Host Reference Voltage. Reference voltage input for the Address, and  
A
Common clock signals of the Host GTL interface.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
35  
Signal Description  
2.2  
DDR2 DRAM Channel A Interface  
Signal Name  
Type  
Description  
SCLK_A[5:0]  
O
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.  
SSTL-1.8  
SCLK_A[5:0]#  
SCS_A[3:0]#  
O
SDRAM Complementary Differential Clock: (3 per DIMM). These are the  
complementary Differential DDR2 Clock signals.  
SSTL-1.8  
O
Chip Select: (1 per Rank). These signals select particular SDRAM  
components during the active state. There is one chip select for each  
SDRAM rank.  
SSTL-1.8  
SMA_A[13:0]  
SBS_A[2:0]  
O
Memory Address: These signals are used to provide the multiplexed row  
and column address to the SDRAM.  
SSTL-1.8  
O
Bank Select: These signals define which banks are selected within each  
SSTL-1.8  
SDRAM rank.  
DDR2: 1-Gb technology is 8 banks.  
SRAS_A#  
SCAS_A#  
SWE_A#  
O
Row Address Strobe: This signal is used with SCAS_A# and SWE_A#  
(along with SCS_A#) to define the SDRAM commands.  
SSTL-1.8  
O
Column Address Strobe: This signal is used with SRAS_A# and SWE_A#  
(along with SCS_A#) to define the SDRAM commands.  
SSTL-1.8  
O
Write Enable: This signal is used with SCAS_A# and SRAS_A# (along with  
SSTL-1.8  
SCS_A#) to define the SDRAM commands.  
SDQ_A[63:0]  
I/O  
SSTL-1.8  
2x  
Data Lines: The SDQ_A[63:0] signals interface to the SDRAM data bus.  
SDM_A[7:0]  
O
SSTL-1.8  
2X  
Data Mask: When activated during writes, the corresponding data groups in  
the SDRAM are masked. There is one SDM_Ax bit for every data byte lane.  
SDQS_A[7:0]  
I/O  
SSTL-1.8  
2x  
Data Strobes: 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.  
SDQS_A[7:0]#  
SCKE_A[3:0]  
SODT_A[3:0]  
I/O  
SSTL-1.8  
2x  
Data Strobe Complements: These are the complementary DDR2 strobe  
signals.  
O
Clock Enable: (1 per Rank). SCKE_Ax 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.  
SSTL-1.8  
O
On Die Termination: Active On-die Termination Control signals for DDR2  
SSTL-1.8  
devices.  
36  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Signal Description  
2.3  
DDR2 DRAM Channel B Interface  
Signal Name  
Type  
Description  
SCLK_B[5:0]  
O
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.  
SSTL-1.8  
SCLK_B[5:0]#  
SCS_B[3:0]#  
O
SDRAM Complementary Differential Clock: (3 per DIMM). These are  
the complementary Differential DDR2 Clock signals.  
SSTL-1.8  
O
Chip Select: (1 per Rank). These signals select particular SDRAM  
components during the active state. There is one chip select for each  
SDRAM rank  
SSTL-1.8  
SMA_B[13:0]  
SBS_B[2:0]  
O
Memory Address: These signals are used to provide the multiplexed row  
and column address to the SDRAM  
SSTL-1.8  
O
Bank Select: These signals define which banks are selected within each  
SSTL-1.8  
SDRAM rank.  
DDR2: 1-Gb technology is 8 banks.  
SRAS_B#  
SCAS_B#  
SWE_B#  
O
Row Address Strobe: This signal is used with SCAS_B# and SWE_B#  
(along with SCS_B#) to define the SDRAM commands.  
SSTL-1.8  
O
Column Address Strobe: This signal is used with SRAS_B# and  
SWE_B# (along with SCS_B#) to define the SDRAM commands.  
SSTL-1.8  
O
Write Enable: This signal is used with SCAS_B# and SRAS_B# (along  
SSTL-1.8  
with SCS_B#) to define the SDRAM commands.  
SDQ_B[63:0]  
I/O  
SSTL-1.8  
2x  
Data Lines: The SDQ_B[63:0] signals interface to the SDRAM data bus.  
SDM_B[7:0]  
O
SSTL-1.8  
2x  
Data Mask: When activated during writes, the corresponding data groups  
in the SDRAM are masked. There is one SDM_Bx for every data byte  
lane.  
SDQS_B[7:0]  
I/O  
SSTL-1.8  
2x  
Data Strobes: 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.  
SDQS_B[7:0]#  
SCKE_B[3:0]  
SODT_B[3:0]  
I/O  
SSTL-1.8  
2x  
Data Strobe Complements: These are the complementary DDR2 Strobe  
signals.  
O
Clock Enable: (1 per Rank). SCKE_Bx 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.  
SSTL-1.8  
O
On Die Termination: Active On-die Termination Control signals for DDR2  
SSTL-1.8  
devices.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
37  
Signal Description  
2.4  
DDR2 DRAM Reference and Compensation  
Signal Name  
Type  
Description  
SRCOMP[1:0]  
SOCOMP[1:0]  
I/O  
System Memory RCOMP  
I/O  
A
DDR2 On-Die DRAM Over Current Detection (OCD) Driver  
Compensation  
SMVREF[1:0]  
I
SDRAM Reference Voltage: These signals are reference voltage inputs for  
A
each SDQ_x, SDM_x, SDQS_x, and SDQS_x# input signals.  
2.5  
PCI Express* Interface Signals (Intel®  
82945G/82945GC/82945P/82945PL Only)  
Unless otherwise specified, PCI Express signals are AC coupled, so the only voltage specified is a  
maximum 1.2 V differential swing.  
Note: PCI Express Interface signals are not on the 82945GZ.  
Signal Name  
Type  
Description  
PCI Express* Receive Differential Pair  
EXP_RXN[15:0]  
EXP_RXP[15:0]  
EXP_TXN[15:0]  
EXP_TXP[15:0]  
EXP_COMPO  
I/O  
PCIE  
O
PCIE  
PCI Express* Transmit Differential Pair  
I
A
PCI Express* Output Current Compensation  
PCI Express* Input Current Compensation  
EXP_COMPI  
I
A
38  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Signal Description  
2.6  
Analog Display Signals (Intel® 82945G/82945GC/  
82945GZ GMCH Only)  
Signal Name  
RED  
Type  
Description  
O
A
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   
routing impedance; however, the terminating resistor to ground will be 75  
(e.g., 75 resistor on the board, in parallel with a 75 CRT load).  
RED#  
O
A
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  
O
A
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   
routing impedance: however, the terminating resistor to ground will be 75  
(e.g., 75 resistor on the board, in parallel with a 75 CRT load).  
GREEN#  
BLUE  
O
A
GREENB Analog Output: This signal is an analog video output from the  
internal color palette DAC. It should be shorted to the ground plane.  
O
A
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   
routing impedance; however, the terminating resistor to ground will be 75  
(e.g., 75 resistor on the board, in parallel with a 75 CRT load).  
BLUE#  
O
A
BLUEB Analog Output: This signal is an analog video output from the  
internal color palette DAC. It should be shorted to the ground plane.  
REFSET  
HSYNC  
O
A
Resistor Set: Set point resistor for the internal color palette DAC. A  
255 1% resistor is required between REFSET and motherboard ground.  
O
CRT Horizontal Synchronization: This signal is used as the horizontal  
2.5V  
sync (polarity is programmable) or “sync interval”. 2.5 V output  
CMOS  
VSYNC  
O
CRT Vertical Synchronization: This signal is used as the vertical sync  
2.5V  
(polarity is programmable). 2.5 V output.  
CMOS  
DDC_CLK  
DDC_DATA  
I/O  
2.5V  
CMOS  
Monitor Control Clock. This signal may be used as the DDC_CLK for a  
secondary multiplexed digital display connector.  
I/O  
Monitor Control Data. This signal may be used as the DDC_Data for a  
2.5V  
secondary multiplexed digital display connector.  
CMOS  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
39  
Signal Description  
2.7  
Clocks, Reset, and Miscellaneous  
Signal  
Name  
Type  
Description  
HCLKP  
I
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. Memory domain clocks are also derived  
from this source.  
HCSL  
HCLKN  
GCLKP  
GCLKN  
I
Differential PCI Express* 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.  
HCSL  
DREFCLKN  
DREFCLKP  
RSTIN#  
I
Display PLL Differential Clock In  
HCSL  
I
Reset In: When asserted, this signal will asynchronously reset the (G)MCH  
logic. This signal is connected to the PCIRST# output of the Intel® ICH7. All  
PCI Express graphics attach output signals will also tri-state compliant to  
PCI Express* Specification, Revision 1.0a.  
HVIN  
This input should have a Schmitt trigger to avoid spurious resets.  
This signal is required to be 3.3 V tolerant.  
PWROK  
EXTTS#  
I
Power OK: When asserted, PWROK is an indication to the (G)MCH that  
core power has been stable for at least 10 us.  
HVIN  
I
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.  
CMOS  
EXP_EN  
I
PCI Express SDVO Concurrent Select  
CMOS  
0 = Only SDVO or PCI Express operational  
1 = SDVO and PCI Express operating simultaneously via PCI Express  
port  
NOTES: For the 82945GZ GMCH and 82945P/82945PL MCH, this signal  
should be pulled low.  
EXP_SLR  
I
PCI Express* Static Lane Reversal/Form Factor Selection: (G)MCH’s  
PCI Express lane numbers are reversed to differentiate Balanced  
Technology Extended (BTX) or ATX form factors.  
CMOS  
0 = (G)MCH’s PCI Express lane numbers are reversed (BTX Platforms)  
1 = Normal operation (ATX Platforms)  
NOTES: This signal does not apply to the 82945GZ.  
ICH_SYNC#  
XORTEST  
ALLZTEST  
O
ICH Sync: This signal is connected to the MCH_SYNCH# signal on the  
ICH7.  
HVCMOS  
I/O  
GTL+  
XOR Test: This signal is used for Bed of Nails testing by OEMs to execute  
XOR Chain test.  
I/O  
All Z Test: As an input this signal is used for Bed of Nails testing by OEMs  
GTL+  
to execute XOR Chain test. It is used as an output for XOR chain testing.  
40  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Signal Description  
2.8  
2.9  
Direct Media Interface (DMI)  
Signal Name  
Type  
Description  
DMI_RXP[3:0]  
DMI_RXN[3:0]  
DMI_TXP[3:0]  
DMI_TXN[3:0]  
I/O  
DMI  
Direct Media Interface: These signals are receive differential pairs (Rx).  
Direct Media Interface: These signals are transmit differential pairs (Tx).  
O
DMI  
Intel® Serial DVO (SDVO) Interface (Intel®  
82945G/82945GC/82945GZ GMCH Only)  
For the 82945G/82945GC GMCH, all but two of the pins in this section are multiplexed with the  
upper 8 lanes of the PCI Express interface.  
Signal Name  
Type  
Description  
SDVOB_CLK-  
O
Serial Digital Video Channel B Clock Complement. This signal is  
PCIE  
multiplexed with EXP_TXN12.  
SDVOB_CLK+  
SDVOB_RED-  
O
PCIE  
Serial Digital Video Channel B Clock. This signal is multiplexed with  
EXP_TXP12.  
O
Serial Digital Video Channel C Red Complement. This signal is  
PCIE  
multiplexed with EXP_TXN15.  
SDVOB_RED+  
SDVOB_GREEN-  
SDVOB_GREEN+  
SDVOB_BLUE-  
SDVOB_BLUE+  
O
PCIE  
Serial Digital Video Channel C Red. This signal is multiplexed with  
EXP_TXP15.  
O
PCIE  
Serial Digital Video Channel B Green Complement. This signal is  
multiplexed with EXP_TXN14.  
O
PCIE  
Serial Digital Video Channel B Green. This signal is multiplexed with  
EXP_TXP14.  
O
PCIE  
Serial Digital Video Channel B Blue Complement. This signal is  
multiplexed with EXP_TXN13.  
O
Serial Digital Video Channel B Blue. This signal is multiplexed with  
PCIE  
EXP_TXP13.  
SDVOC_RED- /  
SDVOB_ALPHA-  
O
PCIE  
Serial Digital Video Channel C Red Complement Channel B Alpha  
Complement. This signal is multiplexed with EXP_TXN11.  
SDVOC_RED+ /  
SDVOB_ALPHA+  
O
PCIE  
Serial Digital Video Channel C Red Channel B Alpha. This signal is  
multiplexed with EXP_TXP11.  
SDVOC_GREEN-  
SDVOC_GREEN+  
SDVOC_BLUE-  
SDVOC_BLUE+  
O
PCIE  
Serial Digital Video Channel C Green Complement. This signal is  
multiplexed with EXP_TXN10.  
O
PCIE  
Serial Digital Video Channel C Green. This signal is multiplexed with  
EXP_TXP10.  
O
PCIE  
Serial Digital Video Channel C Blue Complement. This signal is  
multiplexed with EXP_TXN9.  
O
Serial Digital Video Channel C Blue. This signal is multiplexed with  
PCIE  
EXP_TXP9.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
41  
Signal Description  
Signal Name  
Type  
Description  
SDVOC_CLK-  
O
Serial Digital Video Channel C Clock Complement. This signal is  
PCIE  
multiplexed with EXP_TXN8.  
SDVOC_CLK+  
SDVO_TVCLKIN-  
SDVO_TVCLKIN+  
SDVOB_INT-  
O
PCIE  
Serial Digital Video Channel C Clock. This signal is multiplexed with  
EXP_TXP8.  
I
Serial Digital Video TV-OUT Synchronization Clock Complement.  
This signal is multiplexed with EXP_RXN15.  
PCIE  
I
Serial Digital Video TV-OUT Synchronization Clock. This signal is  
multiplexed with EXP_RXP15.  
PCIE  
I
Serial Digital Video Input Interrupt Complement. This signal is  
PCIE  
multiplexed with EXP_RXN14.  
SDVOB_INT+  
I
Serial Digital Video Input Interrupt. This signal is multiplexed with  
PCIE  
EXP_RXP14.  
SDVOC_INT+  
I
Serial Digital Video Input Interrupt. This signal is multiplexed with  
PCIE  
EXP_RXP10  
SDVOC_INT-  
I
Serial Digital Video Input Interrupt Complement. This signal is  
PCIE  
multiplexed with EXP_RXN10  
SDVO_STALL-  
SDVO_STALL+  
SDVO_CTRLCLK  
SDVO_CTRLDATA  
I
Serial Digital Video Field Stall Complement. This signal is multiplexed  
with EXP_RXN13.  
PCIE  
I
Serial Digital Video Field Stall. This signal is multiplexed with  
EXP_RXP13.  
PCIE  
I/O  
COD  
Serial Digital Video Device Control Clock.  
Serial Digital Video Device Control Data.  
I/O  
COD  
42  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Signal Description  
2.10  
Power and Ground  
Name  
Voltage  
Description  
VCC  
VTT  
1.5 V  
1.2 V  
1.5 V  
1.8 V  
2.5 V  
1.5 V  
1.5 V  
Core Power  
Processor System Bus Power  
PCI Express* and DMI Power  
System Memory Power  
VCC_EXP  
VCCSM  
VCC2  
2.5 V CMOS Power  
VCCA_EXPPLL  
PCI Express PLL Analog Power  
Display PLL A Analog Power  
VCCA_DPLLA  
(GMCH ONLY)  
VCCA_DPLLB  
(GMCH ONLY)  
1.5 V  
Display PLL B Analog Power  
VCCA_HPLL  
VCCA_SMPLL  
VCCA_DAC  
VSS  
1.5 V  
1.5 V  
2.5 V  
0 V  
Host PLL Analog Power  
System Memory PLL Analog Power  
Display DAC Analog Power  
Ground  
VSSA_DAC  
0 V  
Ground  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
43  
Signal Description  
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:  
DRIVE:  
TERM:  
LV:  
Strong drive (to normal value supplied by core logic if not otherwise stated)  
Normal termination devices are turned on  
Low voltage  
HV:  
High voltage  
IN:  
Input buffer enabled  
TRI:  
Tri-state  
PU:  
Weak internal pull-up: 7.2 K– 11.1 K, unless otherwise specified.  
Weak internal pull-down: 600 – 880 unless otherwise specified.  
PD:  
CMCT:  
Common Mode Center Tapped. Differential signals are weakly driven to the  
common mode central voltage.  
STRAP:  
Strap input sampled during assertion edge of PWROK.  
State After  
State During  
RSTIN# Assertion  
Pull-up/  
Pull-down  
Interface  
Signal Name  
I/O  
RSTIN#  
De-assertion  
Host  
HCPURST#  
O
DRIVE LV  
TERM HV after  
Interface  
approximately 1ms  
HADSTB[1:0]#  
HA[35:3]#  
I/O  
I/O  
TERM HV  
TERM HV  
POC  
TERM HV  
STRAP  
HD[63:0]  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
O
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  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
HDSTBP[3:0]#  
HDSTBN[3:0]#  
HDINV[3:0]#  
HADS#  
HBNR#  
HBPRI#  
HDBSY#  
I/O  
O
HDEFER#  
HDRDY#  
HEDRDY#  
HHIT#  
I/O  
O
I/O  
44  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Signal Description  
State After  
RSTIN#  
De-assertion  
State During  
RSTIN# Assertion  
Pull-up/  
Pull-down  
Interface  
Signal Name  
I/O  
HHITM#  
I/O  
I/O  
I/O  
O
I
TERM HV  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
TERM HV  
IN  
TERM HV  
HLOCK#  
TERM HV  
HREQ[4:0]#  
HTRDY#  
TERM HV  
TERM HV  
HRS[2:0]#  
TERM HV  
HBREQ0#  
HPCREQ#  
HDREF  
O
I
TERM HV  
TERM HV  
I
IN  
HRCOMP  
I/O  
I
TRI  
TRI after RCOMP  
RCOMP  
HSWING  
IN  
IN  
HSCOMP  
I/O  
I
TRI  
TRI  
IN  
HACCVREF  
SCLK_A[5:0]  
SCLK_A[5:0]#  
SCS_A[3:0]#  
SMA_A[13:0]  
SBS_A[2:0]  
SRAS_A#  
IN  
System  
Memory  
O
O
O
O
O
O
O
O
I/O  
O
I/O  
I/O  
O
O
O
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
LV  
TRI  
Channel A  
TRI  
TRI  
TRI  
TRI  
SCAS_A#  
TRI  
SWE_A#  
TRI  
SDQ_A[63:0]  
SDM_A[7:0]  
SDQS_A[7:0]  
SDQS_A[7:0]#  
SCKE_A[3:0]  
SCKE_A[3:0]  
SODT_A[3:0]  
TRI  
TRI  
TRI  
TRI  
LV  
LV  
LV  
LV  
LV  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
45  
Signal Description  
State After  
RSTIN#  
De-assertion  
State During  
RSTIN# Assertion  
Pull-up/  
Pull-down  
Interface  
Signal Name  
I/O  
System  
Memory  
SCLK_B[5:0]  
O
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
LV  
TRI  
SCLK_B[5:0]#  
SCS_B[3:0]#  
SMA_B[13:0]  
SBS_B[2:0]  
SRAS_B#  
O
TRI  
Channel B  
O
TRI  
O
TRI  
O
TRI  
O
TRI  
SCAS_B#  
O
TRI  
SWE_B#  
O
TRI  
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  
I/O  
O
TRI  
TRI  
I/O  
I/O  
O
TRI  
TRI  
LV  
O
LV  
LV  
System  
Memory  
I/O  
I/O  
I
TRI  
TRI  
IN  
TRI after RCOMP  
SRCOMP1  
TRI after RCOMP  
Reference  
Comp.  
SMVREF[1:0]  
SOCOMP[1:0]  
IN  
I/O  
TRI  
TRI  
External  
40 resistor  
to ground  
PCI  
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
CMCT  
CMCT  
Express*  
(82945G/8  
2945GC/  
82945P/  
82945PL  
Only)  
CMCT  
CMCT  
CMCT 1.0V  
CMCT 1.0V  
TRI  
CMCT 1.0V  
CMCT 1.0V  
TRI  
O
O
I
TRI  
TRI  
DMI  
DMI_RXN[3:0]  
DMI_RXP[3:0]  
DMI_TXN[3:0]  
DMI_TXP[3:0]  
I/O  
I/O  
O
CMCT  
CMCT  
CMCT  
CMCT  
CMCT 1.0V  
CMCT 1.0V  
CMCT 1.0V  
CMCT 1.0V  
O
46  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Signal Description  
State After  
RSTIN#  
De-assertion  
State During  
RSTIN# Assertion  
Pull-up/  
Pull-down  
Interface  
Signal Name  
I/O  
HCLKN  
I
IN  
IN  
IN  
IN  
IN  
IN  
IN  
HV  
PU  
IN  
IN  
IN  
IN  
IN  
IN  
IN  
HV  
PU  
Clocks  
HCLKP  
I
GCLKN  
I
GCLKP  
I
DREFCLKN  
DREFCLKP  
RSTIN#  
I
I
I
Misc  
PWROK  
I
ICH_SYNC#  
O
INT 10 K  
PU  
EXTTS#  
I
IN  
IN  
BSEL[2:0]  
I/O  
TRI  
TRI  
STRAP  
EXP_SLR  
EXP_EN  
I/O  
I/O  
I/O  
I/O  
I/O  
I/O  
TERM HV  
STRAP  
TERM HV  
TRI  
PD STRAP  
INT 10 K  
PD  
SDVO_CTRLCLK  
(GMCH Only)  
PD  
TRI  
INT 10 K  
PD  
SDVO_CTRLDATA  
(GMCH Only)  
PDSTRAP  
TRI  
XORTEST  
TERM HV  
STRAP  
TERM HV  
TERM HV  
ALLZTEST  
TERM HV  
STRAP  
HSYNC  
O
O
O
O
O
LV  
DAC  
VSYNC  
LV  
RED (GMCH Only)  
RED# (GMCH Only)  
TRI  
TRI  
TRI  
TRI  
TRI  
TRI  
GREEN (GMCH  
Only)  
GREEN# (GMCH  
Only)  
O
TRI  
TRI  
BLUE (GMCH Only)  
O
O
TRI  
TRI  
TRI  
TRI  
BLUE# (GMCH  
Only)  
REFSET  
I/O  
TRI  
0.5*Bandgap  
255 1%  
Resistor to  
Ground  
DDC_CLK  
I/O  
I/O  
IN  
IN  
IN  
IN  
DDC_DATA  
§
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
47  
Signal Description  
48  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Register Description  
3 Register Description  
The (G)MCH contains two sets of software accessible registers, accessed via the Host processor  
I/O address space: Control registers and internal configuration registers.  
Control registers are I/O mapped into the processor I/O space that controls access to PCI and  
PCI Express configuration space (see Section 3.5).  
Internal configuration registers residing within the (G)MCH are partitioned into logical  
device register sets (“logical” since they reside within a single physical device). One register  
set is dedicated to Host Bridge functionality (i.e., DRAM configuration, other chipset  
operating parameters, and optional features). Another register set is dedicated to Host-PCI  
Express Bridge functions (controls PCI Express interface configurations and operating  
parameters). The 82945G/82945G/82945GZ GMCH contains a third register set that is for  
the internal graphics functions.  
The (G)MCH internal registers (I/O Mapped, Configuration and PCI Express Extended  
Configuration registers) are accessible by the Host 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, which can only be accessed as a DWord.  
All multi-byte numeric fields use "little-endian" ordering (i.e., lower addresses contain the least  
significant parts of the field). Registers that reside in bytes 256 through 4095 of each device may  
only be accessed using memory mapped transactions in DWord (32-bit) quantities.  
Some of the (G)MCH registers described in this chapter 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 that 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 bring up the system. Hence, it does not represent the optimal system configuration. It  
is the responsibility of the system initialization software (usually BIOS) to properly determine the  
DRAM configurations, operating parameters, and optional system features that are applicable, and  
to program the (G)MCH registers accordingly.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
49  
Register Description  
3.1  
Register Terminology  
The following table shows the register-related terminology that is used.  
Item  
Description  
RO  
Read Only bit(s). Writes to these bits have no effect.  
RS/WC  
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.  
R/W  
Read / Write bit(s). These bits can be read and written.  
R/WC  
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.  
R/WC/S  
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).  
R/W/L  
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).  
R/W/S  
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/WSC  
R/WSC/L  
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).  
R/WO  
W
Write Once bit(s). Once written, bits with this attribute become Read Only. These bits can  
only be cleared by a Reset.  
Write Only. Registers with this attribute have bits that 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.  
3.2  
Platform Configuration  
In platforms that support DMI (such as, this (G)MCH) the configuration structure is significantly  
different from hub architectures prior to the Intel® 915x Express chipsets. The DMI physically  
connects the (G)MCH and the ICH7; thus, from a configuration standpoint, the DMI is logically  
PCI bus 0. As a result, all devices internal to the (G)MCH and the ICH7 appear to be on PCI  
bus 0.  
Note: The ICH7 internal LAN controller does not appear on bus 0; it appears on the external PCI bus  
(bus number is configurable).  
The system’s primary PCI expansion bus is physically attached to the ICH7 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.  
50  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Register Description  
Note: A physical PCI bus 0 does not exist; DMI and the internal devices in the (G)MCH and ICH7  
logically constitute PCI Bus 0 to configuration software (see Figure 3-1).  
Figure 3-1. Conceptual Chipset Platform PCI Configuration Diagram  
Processor  
(G)MCH  
PCI Configuration Window in  
I/O Space  
DRAM Controller Interface  
Bus 0, Device 0  
Host-PCI Express Bridge  
Bus 0, Device 1 (Intel®  
82945G/82945P/82945PL  
GMCH Only)  
Internal Graphics Controller  
Bus 0, Device 2  
(Intel® 82945G/82945GZ  
GMCH Only)  
Direct Media Interface (DMI)  
PCI_Config_Dia  
The (G)MCH contains three PCI devices within a single physical component. The configuration  
registers for the three devices are mapped as devices residing on PCI bus 0.  
Device 0: Host Bridge Controller. Logically, this device is 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 (82945G/82945GC/82945P/82945PL (G)MCH  
Only). Logically, this device 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 (82945G/82945GC/82945GZ GMCH Only).  
Logically, this device appears as a PCI device residing on PCI bus 0. Physically, device 2  
contains the configuration registers for 3D, 2D, and display functions.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
51  
Register Description  
Figure 3-2. Register Organization  
PCI Express* Egress Port  
(RCRB)  
FFFh  
Device 2 Configuration  
Registers: Internal Graphics  
(Intel® 82945G/82945GZ  
GMCH Only)  
VC1 (Isochronous) Port  
Arbitration Controls  
FFFh  
000h  
FFFh  
Unused  
DMI Root Complex Register  
Block (RCRB)  
0FFh  
(G)MCH-ICH7 Serial Interface  
(DMI) Controls:  
Analog Controls  
Error Reporting Controls  
VC Control  
Mirror of bits needed by  
graphics driver  
Graphics Thermal Controls  
000h  
000h  
Device 1 Configuration  
Registers: PCI Express X16  
PCI Express Address Range  
FFFh  
0FFF FFFFh  
PCI Express x16 Controls:  
Analog Controls  
Error Reporting Controls  
VC Controls  
Accessed only by PCI  
Express enhanced access  
mechanism. 4 KB block  
allocated for each potential  
device in root hierarchy.  
Hot Plug/Slot Controls  
0FFh  
Device Level Controls  
Device 2 Range  
Device 1 Range  
Device 0 Range  
000h  
0000 0000h  
Device 0 Configuration  
Registers  
FFFh  
Device 0 MMIO Registers:  
(G)MCH Control  
3FFFh  
Unused  
Thermal Sensor  
PSB Analog Controls  
SM Analog Crontrols  
(Rcomp+)  
0FFh  
CH 0/1 Analog Controls  
CH 0/1 Timing Controls  
Ch 0/1 Throttling  
Ch 0/1 Oranization  
Arbiter Controls  
Device Level Controls, PAM  
EPBAR  
DMI BAR  
PCIEXBAR  
0000h  
MCHBAR  
000h  
Note:  
1. Diagram not to scale  
2. PCI Express is for the Intel® 82945G/82945P/82945PL (G)MCH Only.  
3. Internal Graphics Device is for the Intel® 82945G/82945GZ (G)MCH Only.  
Reg_Org  
NOTES:  
1.  
2.  
3.  
4.  
5.  
Very high level representation. Many details omitted.  
Internal graphics memory mapped registers are not shown.  
Only Device 1 uses PCI Express extended configuration space.  
Device 0 and Device 2 use only standard PCI configuration space.  
Hex numbers represent address range size and not actual locations.  
52  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Register Description  
3.3  
Configuration Mechanisms  
The processor is the originator of configuration cycles; thus, the FSB is the only interface in the  
platform where these mechanisms are used. The MCH translates transactions received through  
both configuration mechanisms to the same format.  
3.3.1  
Standard PCI Configuration Mechanism  
The following is the mechanism for translating processor I/O bus cycles to configuration cycles.  
The PCI specification 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 uses 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 DWord I/O write cycle is used to place a value into  
CONFIG_ADDRESS that specifies the PCI bus, the device on that bus, the function within the  
device, and a specific configuration register of the device function being accessed.  
CONFIG_ADDRESS[31] must be 1 to enable a configuration cycle. CONFIG_DATA then  
becomes a window into the four bytes of configuration space specified by the contents of  
CONFIG_ADDRESS. Any read or write to CONFIG_DATA 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  
PCI Express* Enhanced Configuration Mechanism (Intel®  
82945G/82945GC/82945P/82945PL (G)MCH Only)  
PCI Express extends the configuration space to 4096 bytes per device/function as compared to  
256 bytes allowed by the PCI Local Bus 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 Standard PCI configuration  
mechanism or using the PCI Express enhanced configuration mechanism described in this section.  
The extended configuration registers may only be accessed using the PCI Express enhanced  
configuration 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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
53  
Register Description  
The PCI Express enhanced configuration 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 block of addresses  
below 4 GB for the configuration space associated with busses, devices, and functions that are  
potentially a part of the PCI Express root complex hierarchy. The PCIEXBAR register contains  
controls to limit the size of this reserved memory-mapped space; 256 MB is the amount of  
address space required to reserve space for every bus, device, and function is currently available.  
Options for 128 MB and 64 MB are available to free up those addresses for other uses. In these  
cases the number of busses and all of their associated devices and functions are limited to 128 or  
64 busses respectively.  
The PCI Express configuration transaction header includes an additional 4 bits  
(ExtendedRegisterAddress[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 3-3. Memory Map-to-PCI Express* Device Configuration Space  
FFFFFFFh  
FFFFFh  
FFFh  
7FFFh  
Bus 255  
Device 31  
Function 7  
PCI Express*  
Extended  
Configuration  
Space  
FFFFh  
7FFFh  
1FFFh  
FFFh  
FFh  
3Fh  
1FFFFFh  
PCI  
Compatible  
Config Space  
Bus 1  
Bus 0  
Function 1  
Function 0  
Device 1  
Device 0  
FFFFFh  
0h  
PCI  
Compatible  
Config Header  
Located By PCI  
Express Base  
Address  
MemMap_PCIExpress  
As with PCI devices, each PCI Express 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.  
To access this space (steps 1, 2, and 3 are completed only once by BIOS):  
1. use the PCI compatible configuration mechanism to enable the PCI Express enhanced  
configuration mechanism by writing 1 to bit 0 of the PCIEXBAR 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 or read  
that register.  
54  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Register Description  
3.4  
Routing Configuration Accesses  
The (G)MCH supports two PCI related interfaces: DMI and PCI Express. The (G)MCH is  
responsible for routing PCI and PCI Express configuration cycles to the appropriate device that is  
an integrated part of the (G)MCH or to one of these two interfaces. Configuration cycles to the  
ICH7 internal devices and Primary PCI (including downstream devices) are routed to the ICH7  
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 device or associated link.  
Figure 3-4. Intel® 82945G/82945GC (G)MCH Configuration Cycle Flow Chart  
DWord I/O Write to  
CONFIG_ADDRESS  
with bit 31 = 1  
I/O Read/Write to  
CONFIG_DATA  
Yes  
Bus# = 0  
No  
GMCH Generates  
Type 1 Access to  
PCI Express  
Bus# > Sec Bus  
Bus# Sub Bus in  
GMCH Dev 1  
Yes  
Yes  
Dev# = 0 &  
Func# = 0  
GMCH Claims  
No  
No  
Dev# = 1 &  
Dev# 1 Enabled  
& Func# = 0  
Bus# =  
Secondary Bus in  
GMCH Dev 1  
Yes  
GMCH Claims  
Yes  
No  
No  
Dev# = 2 &  
GMCH Generates DMI  
Type 1Configuration  
Cycle  
(Func#=0 & Dev#2,  
Func#0 Enabled)  
OR  
Yes  
GMCH Claims  
(Func#=1 & Dev#2,  
Funcs#0&1 Enabled)  
No  
GMCH Generates  
Type 0 Access  
to PCI Express  
Yes  
Device# = 0  
GMCH Generates DMI  
Type 0 Configuration  
Cycle  
No  
GMCH allows cycle to  
go to DMI resulting in  
Master Abort  
Config_Cyc_Flow  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
55  
Register Description  
3.4.1  
3.4.2  
Internal Device Configuration Accesses  
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. If the targeted PCI Bus 0 device exists in the  
(G)MCH and is not disabled, the configuration cycle is claimed by the appropriate device.  
Bridge Related Configuration Accesses  
Configuration accesses on PCI Express or DMI are PCI Express configuration TLPs (Transaction  
Layer Packets).  
Bus Number [7:0] is Header Byte 8 [7:0]  
Device Number [4:0] is Header Byte 9 [7:3]  
Function Number [2:0] is Header Byte 9 [2:0]  
Special fields for this type of TLP are:  
Extended Register Number [3:0] is Header Byte 10 [3:0]  
Register Number [5:0] is Header Byte 11 [7:2]  
See the PCI Express specification for more information on both the PCI 2.3 compatible and PCI  
Express Enhanced Configuration Mechanism and transaction rules.  
3.4.2.1  
PCI Express* Configuration Accesses (Intel®  
82945G/82945GC/82945P/82945PL (G)MCH Only)  
When the Bus Number of a type 1 Standard PCI configuration cycle or PCI Express enhanced  
configuration access matches the Device 1 Secondary Bus Number, a PCI Express type 0  
configuration TLP is generated on the PCI Express link targeting the device directly on the  
opposite side of the link. This should be Device 0 on the bus number assigned to the PCI Express  
link (likely Bus 1).  
The device on the other side of the link must be Device 0. The (G)MCH will Master Abort any  
type 0 configuration access to a non-zero device number. If there is to be more than one device on  
that side of the link, there must be a bridge implemented in the downstream device.  
When the Bus Number of a type 1 Standard PCI Configuration cycle or PCI Express enhanced  
configuration access is within the claimed range (between the upper bound of the bridge device’s  
Subordinate Bus Number register and the lower bound of the bridge device’s Secondary Bus  
Number register) but does not match the Device 1 Secondary Bus Number, a PCI Express type 1  
configuration TLP is generated on the secondary side of the PCI Express link.  
PCI Express Configuration Writes:  
Internally, the host interface unit translates writes to PCI Express extended configuration  
space to configuration writes on the backbone.  
Writes to extended space are posted on the FSB, but non-posted on the PCI Express or DMI  
(i.e., translated to configuration writes)  
56  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Register Description  
3.4.2.2  
DMI Configuration Accesses  
Accesses to disabled (G)MCH internal devices, bus numbers not claimed by the Host-PCI  
Express bridge, or PCI Bus 0 devices not part of the (G)MCH will subtractively decode to the  
ICH7 and consequently be forwarded over the DMI via a PCI Express configuration TLP.  
If the Bus Number is zero, the (G)MCH generates a type 0 configuration cycle TLP on DMI. If  
the Bus Number is non-zero, and falls outside the range claimed by the Host-PCI Express bridge,  
the (G)MCH generates a type 1 configuration cycle TLP on DMI.  
The ICH7 routes configuration accesses in a manner similar to the (G)MCH. The ICH7 decodes  
the configuration TLP and generates a corresponding configuration access. Accesses targeting a  
device on PCI Bus 0 may be claimed by an internal device. The ICH7 compares the non-zero Bus  
Number with the Secondary Bus Number and Subordinate Bus Number registers of its PCI-to-  
PCI bridges to determine if the configuration access is meant for Primary PCI, or some other  
downstream PCI bus or PCI Express link.  
Configuration accesses that are forwarded to the ICH7, but remain unclaimed by any device or  
bridge, will result in a master abort.  
3.5  
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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
57  
Register Description  
3.5.1  
CONFIG_ADDRESS—Configuration Address Register  
I/O Address:  
Default Value:  
Access:  
0CF8h (Accessed as a DWord)  
00000000h  
R/W  
Size:  
32 bits  
CONFIG_ADDRESS is a 32-bit register that can be accessed only as a DWord. A Byte or Word  
reference will "pass through" the Configuration Address Register and 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  
Description  
31  
R/W  
0b  
PCI Configuration Space Enable (CFGE):  
1 = Enabled. Accesses to PCI configuration space are Enabled.  
0 = Disabled.  
Reserved  
30:24  
23:16  
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 2), 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*.  
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.  
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.  
15:11  
R/W  
00h  
Device Number: This field selects one agent on the PCI bus selected by the Bus  
Number. When the Bus Number field is 00h, 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, and Device Number 2 for the  
Internal Graphics Control (82945G/82945GC/82945GZ GMCH only). Therefore,  
when the  
Bus Number =0 and the Device Number equals 0, 1, or 2  
(82945G/82945GC/82945GZ GMCH only), the internal GMCH 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.  
58  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Register Description  
Bit  
Access  
&
Default  
Description  
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  
1:0  
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.  
Reserved  
3.5.2  
CONFIG_DATA—Configuration Data Register  
I/O Address:  
Default Value:  
Access:  
0CFCh  
00000000h  
R/W  
Size:  
32 bits  
CONFIG_DATA is a 32-bit read/write window into configuration space. The portion of  
configuration space that is referenced by CONFIG_DATA is determined by the contents of  
CONFIG_ADDRESS.  
Bit  
Access &  
Default  
Description  
31:0  
R/W  
0000 0000h  
Configuration Data Window (CDW): If bit 31 of the CONFIG_ADDRESS  
Register 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.  
§
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
59  
Register Description  
60  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4 Host Bridge/DRAM Controller  
Registers (D0:F0)  
The DRAM Controller registers are in Device 0 (D0), Function 0 (F0). Table 4-1 provides an  
address map of the D0:F0 registers listed by address offset in ascending order. Section 4.1  
provides a detailed bit description of the registers.  
Warning: Address locations that are not listed are considered Intel Reserved registers locations. Reads to  
reserved register locations 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 simply 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. Host Bridge/DRAM Controller Register Address Map (D0:F0)  
Address  
Offset  
Default  
Value  
Symbol  
Register Name  
Vendor Identification  
Access  
00–01h  
02–03h  
04–05h  
06–07h  
08h  
VID  
DID  
8086h  
2770h  
0006h  
0090h  
RO  
RO  
Device Identification  
PCI Command  
PCICMD  
PCISTS  
RID  
RO, R/W  
RO, R/WC  
RO  
PCI Status  
Revision Identification  
see register  
description  
09–0Bh  
0Ch  
CC  
Class Code  
00h  
RO  
Reserved  
0Dh  
MLT  
Master Latency Timer  
Header Type  
00h  
RO  
RO  
0Eh  
HDR  
00h  
0F–2Bh  
2C–2Dh  
2E–2Fh  
30–33h  
34h  
Reserved  
SVID  
SID  
Subsystem Vendor Identification  
Subsystem Identification  
Reserved  
0000h  
0000h  
R/WO  
R/WO  
CAPPTR  
Capabilities Pointer  
Reserved  
E0h  
RO  
35–3Fh  
40–43h  
44–47h  
EPBAR  
MCHBAR  
Egress Port Base Address  
00000000h  
00000000h  
RO  
R/W  
GMCH Memory Mapped Register Range  
Base Address  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
61  
Host Bridge/DRAM Controller Registers (D0:F0)  
Address  
Symbol  
Offset  
Default  
Value  
Register Name  
Access  
48–4Bh  
PCIEXBAR  
PCI Express* Register Range Base Address  
(Intel® 82945G/82945GC/82945P/82945PL  
(G)MCH Only)  
E0000000h  
R/W  
4C–4Fh  
DMIBAR  
Root Complex Register Range Base  
Address  
00000000h  
R/W  
50–51h  
52–53h  
Reserved  
GGC  
GMCH Graphics Control Register  
0030h  
R/W/L  
(82945G/82945GC/82945GZ GMCH only)  
54–57h  
DEVEN  
Device Enable  
See register  
description  
R/W  
58–8Fh  
90h  
Reserved  
PAM0  
PAM1  
PAM2  
PAM3  
PAM4  
PAM5  
PAM6  
LAC  
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  
00h  
00h  
00h  
00h  
00h  
00h  
00h  
00h  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
R/W  
91h  
92h  
93h  
94h  
95h  
96h  
97h  
98–9Bh  
9Ch  
9Dh  
Reserved  
TOLUD  
SMRAM  
Top of Low Usable DRAM  
System Management RAM Control  
08h  
00h  
R/W  
RO, R/W,  
R/W/L  
9Eh  
ESMRAMC  
Extended System Management RAM Control  
Reserved  
38h  
RO, R/W/L  
9F–C7h  
C8–C9h  
CA–CBh  
CC–DBh  
DC–DFh  
E0–E8h  
ERRSTS  
ERRCMD  
Error Status  
0000h  
0000h  
RO, R/W/L  
R/W  
Error Command  
Reserved  
SKPD  
Scratchpad Data  
Capability Identifier  
00000000h  
R/W  
CAPID0  
See register  
description  
RO  
62  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1  
Device 0 Configuration Register Details  
4.1.1  
VID—Vendor Identification (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
00h  
8086h  
RO  
Size:  
16 bits  
This register, combined with the Device Identification register, uniquely identifies any PCI  
device.  
Bit  
Access  
&
Default  
Description  
15:0  
RO  
Vendor Identification Number (VID): This field provides the PCI standard  
8086h  
identification for Intel.  
4.1.2  
DID—Device Identification (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
02h  
2770h  
RO  
Size:  
16 bits  
This register, combined with the Vendor Identification register, uniquely identifies any PCI  
device.  
Bit  
Access &  
Default  
Description  
15:0  
RO  
Device Identification Number (DID): This field provides an identifier assigned to  
2770h  
the (G)MCH core/primary PCI device.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
63  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.3  
PCICMD—PCI Command (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
04h  
0006h  
RO, R/W  
16 bits  
Size:  
Since (G)MCH Device 0 does not physically reside on Primary PCI bus, many of the bits are not  
implemented.  
Bit  
Access &  
Default  
Description  
15:10  
9
Reserved  
RO  
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.  
8
R/W  
0b  
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  
Intel® ICH7.  
1 = 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.  
0 = The SERR message is not generated by the (G)MCH for Device 0.  
NOTE: 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
RO  
0b  
Address/Data Stepping Enable (ADSTEP): Hardwired to 0. Address/data  
stepping is not implemented in the (G)MCH.  
RO  
0b  
Parity Error Enable (PERRE): Hardwired to 0. PERR# is not implemented by the  
(G)MCH.  
RO  
0b  
VGA Palette Snoop Enable (VGASNOOP): Hardwired to 0. The (G)MCH does  
not implement this bit.  
RO  
0b  
Memory Write and Invalidate Enable (MWIE): Hardwired to 0. The (G)MCH will  
never issue memory write and invalidate commands.  
3
2
Reserved  
RO  
1b  
Bus Master Enable (BME): Hardwired to 1. The (G)MCH is always enabled as a  
master.  
1
0
RO  
1b  
Memory Access Enable (MAE): Hardwired to 1. The (G)MCH always allows  
access to main memory.  
RO  
0b  
I/O Access Enable (IOAE): Hardwired to 0. This bit is not implemented.  
64  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.4  
PCISTS—PCI Status (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
06h  
0090h  
RO, R/WC  
16 bits  
Size:  
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  
15  
14  
Access &  
Default  
Description  
RO  
0b  
Detected Parity Error (DPE): Hardwired to 0. Not implemented.  
Signaled System Error (SSE): Software clears this bit by writing a 1 to it.  
R/WC  
0b  
1 = (G)MCH Device 0 generated a 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.  
0 = (G)MCH Device 0 did Not generate a SERR message over DMI.  
13  
12  
R/WC  
0b  
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.  
0 = (G)MCH did Not generate a DMI request that receives an Unsupported  
Request completion packet.  
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.  
0 = (G)MCH did Not generate a DMI request that receives a Completer Abort  
completion packet.  
11  
RO  
0b  
Signaled Target Abort Status (STAS): Hardwired to 0. Not implemented. The  
(G)MCH will not generate a Target Abort DMI completion packet or Special Cycle.  
10:9  
RO  
00b  
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.  
8
7
RO  
0b  
Master Data Parity Error Detected (DPD): Hardwired to 0. Not implemented.  
PERR signaling and messaging are not implemented by the (G)MCH.  
RO  
1b  
Fast Back-to-Back (FB2B): Hardwired to 1. Device 0 does not physically connect  
to the Primary PCI. This bit is set to 1 (indicating fast back-to-back capability) so  
that the optimum setting for the Primary PCI is not limited by the (G)MCH.  
6
5
Reserved  
RO  
0b  
66 MHz Capable: Hardwired to 0. Does not apply to PCI Express*.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
65  
Host Bridge/DRAM Controller Registers (D0:F0)  
Bit  
Access &  
Default  
Description  
4
RO  
1b  
Capability List (CLIST): 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 the CAPPTR register (address offset 34h). The  
CAPPTR register contains an offset pointing to the start address within  
configuration space of this device where the Capability standard register resides.  
3:0  
Reserved  
4.1.5  
RID—Revision Identification (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
08h  
See bit description  
RO  
Size:  
8 bits  
This register contains the revision number of the (G)MCH Device 0.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Revision Identification Number (RID): This is an 8-bit value that indicates the  
revision identification number for the (G)MCH Device 0. Refer to the Intel®  
945G/945GC/945GZ/945P/945PL 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:  
0
09h  
060000h  
RO  
Size:  
24 bits  
This register identifies the basic function of the device, a more specific sub-class, and a register-  
specific programming interface.  
Bit  
Access &  
Default  
Description  
23:16  
RO  
Base Class Code (BCC): This is an 8-bit value that indicates the base class code  
06h  
for the (G)MCH.  
06h = Bridge device.  
15:8  
7:0  
RO  
00h  
Sub-Class Code (SUBCC): This is an 8-bit value that indicates the category of  
bridge for the (G)MCH.  
00h = Host Bridge.  
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.  
66  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.7  
MLT—Master Latency Timer (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
0Dh  
00h  
RO  
8 bits  
Size:  
Device 0 in the (G)MCH is not a PCI master. Therefore, this register is not implemented.  
Bit  
Access &  
Default  
Description  
7:0  
Reserved  
4.1.8  
HDR—Header Type (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
0Eh  
00h  
RO  
8 bits  
Size:  
This register identifies the header layout of the configuration space. No physical register exists at  
this location.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
00h  
PCI Header (HDR): This field always returns 0 to indicate that the (G)MCH is a  
single function device with standard header layout. Reads and writes to this  
location have no effect.  
4.1.9  
SVID—Subsystem Vendor Identification (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
2Ch  
0000h  
R/WO  
16 bits  
Size:  
This value is used to identify the vendor of the subsystem.  
Bit  
Access &  
Default  
Description  
15:0  
R/WO  
0000h  
Subsystem Vendor ID (SUBVID): This field should be programmed during boot-  
up to indicate the vendor of the system board. After it has been written once, it  
becomes read only.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
67  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.10  
SID—Subsystem Identification (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
2Eh  
0000h  
R/WO  
16 bits  
Size:  
This value is used to identify a particular subsystem.  
Bit  
Access &  
Default  
Description  
15:0  
R/WO  
0000h  
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:  
0
34h  
E0h  
RO  
8 bits  
Size:  
The CAPPTR register provides the offset that is the pointer to the location of the first device  
capability in the capability list.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Pointer to the offset of the first capability ID register block: In this case the  
E0h  
first capability is the product-specific Capability Identifier (CAPID0).  
68  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.12  
EPBAR—Egress Port Base Address (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
40h  
00000000h  
RO  
Size:  
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, the Egress Port MMIO Base Address field in this register is disabled and must be  
enabled by writing a 1 to the EPBAREN bit.  
Bit  
Access &  
Default  
Description  
31:12  
R/W  
Egress Port MMIO Base Address: This field corresponds to bits 31:12 of the  
00000h  
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.  
11:1  
0
Reserved  
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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
69  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.13  
MCHBAR—(G)MCH Memory Mapped Register Range Base  
Address (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
44h  
00000000h  
R/W  
Size:  
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, the (G)MCH Memory Mapped Base Address field in this register is disabled and must  
be enabled by writing a 1 to the MCHBAREN bit.  
Bit  
Access &  
Default  
Description  
31:14  
R/W  
(G)MCH Memory Mapped Base Address: This field corresponds to bits 31:14 of  
00000h  
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 memory-mapped  
register set.  
13:1  
0
Reserved  
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  
70  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.14  
PCIEXBAR—PCI Express* Register Range Base Address  
(D0:F0) (Intel® 82945G/82945GC/82945P/82945PL (G)MCH  
Only)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
48h  
E0000000h  
R/W  
Size:  
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. This window of up to 256-MB does  
not contain actual physical memory that can be addressed. The actual length is determined by a  
field in this register. Each PCI Express hierarchy requires a PCI Express ase register. The  
(G)MCH supports one PCI Express hierarchy.  
The region reserved by this register does not alias to any PCI 2.3 compliant memory-mapped  
space. For example, MCHBAR reserves a 16-KB space outside of PCIEXBAR space. It cannot be  
overlaid on the space reserved by PCIEXBAR for device 0.  
On reset, this register is disabled and must be enabled by writing a 1 to the enable field in this  
register. This base address shall be assigned on a boundary consistent with the number of buses  
defined by the Length field in this register), above TOLUD and still within total 32 bit  
addressable memory space.  
All other bits not decoded are read only 0. The PCI Express Base Address cannot be less than the  
maximum address written to the top of physical memory register (TOLUD). Software must ensure  
that these ranges do not overlap with known ranges located above TOLUD.  
Bit  
Access &  
Default  
Description  
31:28  
R/W  
Eh  
PCI Express* Base Address: This field corresponds to bits 31:28 of the base  
address for PCI Express enhanced configuration space. BIOS will program this  
register resulting in a base address for a contiguous memory address space; size  
is defined by bits 2:1 of this register.  
This base address shall be assigned on a boundary consistent with the number of  
buses (defined by the Length field in this register) above TOLUD and still within  
total 32-bit addressable memory space. The address bits decoded depends on the  
length of the region defined by this register.  
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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
71  
Host Bridge/DRAM Controller Registers (D0:F0)  
Bit  
Access &  
Default  
Description  
27  
R/W  
0b  
128 MB Base Address Mask (128ADMSK): This bit is either part of the PCI  
Express Base Address (R/W) or part of the Address Mask (RO, read 0b),  
depending on the value of bits 2:1 in this register.  
26  
R/W  
0b  
64 MB Base Address Mask (64ADMSK): This bit is either part of the PCI Express  
Base Address (R/W) or part of the Address Mask (RO, read 0b), depending on the  
value of bits 2:1 in this register  
25:3  
2:1  
Reserved  
R/W  
00b  
Length (LENGTH): This field describes the length of this region.  
00 = 256 MB (buses 0–255). Bits 31:28 are decoded in the PCI Express Base  
Address Field  
01 = 128 MB (Buses 0–127). Bits 31:27 are decoded in the PCI Express Base  
Address Field.  
10 = 64 MB (Buses 0–63). Bits 31:26 are decoded in the PCI Express Base  
Address Field.  
11 = Reserved  
0
R/W  
0h  
PCIEXBAR Enable (PCIEXBAREN):  
0 = The PCIEXBAR register is disabled. Memory read and write transactions  
proceed as if there were no PCIEXBAR register. PCIEXBAR bits 31:26 are  
R/W with no functionality behind them.  
1 = The PCIEXBAR register is enabled. Memory read and write transactions  
whose address bits 31:26 match PCIEXBAR will be translated to  
configuration reads and writes within the (G)MCH.  
72  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.15  
DMIBAR—Root Complex Register Range Base Address  
(D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
4Ch  
00000000h  
R/W  
Size:  
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 reserved by this register does not alias to any PCI 2.3 compliant memory-mapped space.  
On reset, the DMI Base Address field in this register is disabled and must be enabled by writing a  
1 to the DMIBAREN bit.  
Bit  
Access &  
Default  
Description  
31:12  
R/W  
DMI Base Address: This field corresponds to bits 31:12 of the base address DMI  
00000 h  
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 (2 GB for  
the 82945GC, 82945GZ and 82945PL).  
System Software uses this base address to program the DMI register set.  
Reserved  
11:1  
0
R/W  
0b  
DMIBAR Enable (DMIBAREN):  
0 = DMIBAR is disabled and does not claim any memory.  
1 = DMIBAR memory-mapped accesses are claimed and decoded appropriately.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
73  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.16  
GGC—GMCH Graphics Control Register (D0:F0) (Intel®  
82945G/82945GC/82945GZ GMCH Only)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
52h  
0030h  
R/W/L  
16 bits  
Size:  
Bit  
Access &  
Default  
Descriptions  
15:7  
6:4  
Reserved  
R/W/L  
011 b  
Graphics Mode Select (GMS): This field selects the amount of main memory  
that is pre-allocated to support the internal graphics device in VGA (non-linear)  
and native (linear) modes. BIOS ensures that memory is pre-allocated only when  
internal graphics is enabled.  
000 = No memory pre-allocated. Device 2 (IGD) does not claim VGA cycles  
(Memory and I/O), and the Sub-Class Code field within D2:F0 Class Code  
register is 80h.  
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 = Reserved  
101 = Reserved  
110 = Reserved  
111 = Reserved  
NOTE: This register is locked and becomes read only when the D_LCK bit in the  
SMRAM register is set.  
3:2  
1
Reserved  
R/W  
0 b  
IGD VGA Disable (IVD):  
0 = Enable. Device 2 (IGD) claims VGA cycles (memory and I/O); the Sub-Class  
Code within Device 2 Class Code register is 00.  
1 = Disable. Device 2 (IGD) does not claim VGA cycles (memory and I/O); the  
Sub-Class Code field within D2:F0 Class Code register is 80h.  
0
Reserved  
74  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.17  
DEVEN—Device Enable (D0:F0)  
PCI Device:  
0
Address Offset:  
Default Value:  
54h  
82945G/82945GC/82945GZ GMCH: 0000001Bh  
82945P/82945PL MCH: 00000003h  
Access:  
Size:  
R/W  
32 bits  
This register allows for enabling/disabling of PCI devices and functions that are within the  
(G)MCH.  
Bit  
Access &  
Default  
Description  
31:5  
4
Reserved  
R/W  
1b  
(GMCH)  
82945G/82945GC/82945GZ GMCH  
Internal Graphics Engine Function 1 (D2F1EN):  
0 = Disable. Bus0:D2:F1 is disabled and hidden  
1 = Enable. Bus0:D2:F1 is enabled and visible  
0b  
(MCH)  
NOTE: Setting this bit to enabled when bit 3 is 0 has no meaning.  
82945P/82945PL MCH  
Reserved.  
3
R/W  
1b  
(GMCH)  
82945G/82945GC/82945GZ GMCH  
Internal Graphics Engine Function 0 (D2F0EN):  
0 = Disable. Bus0:D2:F0 is disabled and hidden  
1 = Enable. Bus0:D2:F0 is enabled and visible  
82945P/82945PL MCH  
0b  
(MCH)  
Reserved  
2
1
Reserved  
R/W  
1b  
82945G/82945GC/82945P/82945PL (G)MCH  
PCI Express* Port (D1EN):  
0 = Disable. Bus0:D1:F0 is disabled and hidden.  
1 = Enable. Bus0:D1:F0 is enabled and visible.  
82945GZ GMCH  
Reserved  
0
RO  
1b  
Host Bridge: Hardwired to 1. Bus0:D0:F0 can not be disabled.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
75  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.18  
PAM0—Programmable Attribute Map 0 (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
90h  
00h  
R/W  
8 bits  
Size:  
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. 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  
Description  
7:6  
5:4  
Reserved  
R/W  
00b  
0F0000h–0FFFFFh Attribute (HIENABLE): This field controls the steering of read  
and write cycles that addresses the BIOS area from 0F0000 to 0FFFFF.  
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 occur (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.  
76  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.19  
PAM1—Programmable Attribute Map 1 (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
91h  
00h  
R/W  
8 bits  
Size:  
This register controls the read, write, and shadowing attributes of the BIOS areas from 0C0000h–  
0C7FFFh.  
Bit  
Access &  
Default  
Description  
7:6  
5:4  
Reserved  
R/W  
00b  
0C4000h–0C7FFFh 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.  
Reserved  
3:2  
1:0  
R/W  
00b  
0C0000h–0C3FFFh 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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
77  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.20  
PAM2—Programmable Attribute Map 2 (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
92h  
00h  
R/W  
8 bits  
Size:  
This register controls the read, write, and shadowing attributes of the BIOS areas from 0C8000h–  
0CFFFFh.  
Bit  
Access &  
Default  
Description  
7:6  
5:4  
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.  
Reserved  
3:2  
1:0  
R/W  
00b  
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.  
78  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.21  
PAM3—Programmable Attribute Map 3 (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
93h  
00h  
R/W  
8 bits  
Size:  
This register controls the read, write, and shadowing attributes of the BIOS areas from 0D0000h–  
0D7FFFh.  
Bit  
Access &  
Default  
Description  
7:6  
5:4  
Reserved  
R/W  
00 b  
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.  
Reserved  
3:2  
1:0  
R/W  
00 b  
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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
79  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.22  
PAM4—Programmable Attribute Map 4 (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
94h  
00h  
R/W  
8 bits  
Size:  
This register controls the read, write, and shadowing attributes of the BIOS areas from 0D8000h–  
0DFFFFh.  
Bit  
Access &  
Default  
Description  
7:6  
5:4  
Reserved  
R/W  
00 b  
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.  
Reserved  
3:2  
1:0  
R/W  
00 b  
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.  
80  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.23  
PAM5—Programmable Attribute Map 5 (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
95h  
00h  
R/W  
8 bits  
Size:  
This register controls the read, write, and shadowing attributes of the BIOS areas from 0E0000h–  
0E7FFFh.  
Bit  
Access &  
Default  
Description  
7:6  
5:4  
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.  
Reserved  
3:2  
1:0  
R/W  
00b  
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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
81  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.24  
PAM6—Programmable Attribute Map 6 (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
96h  
00h  
R/W  
8 bits  
Size:  
This register controls the read, write, and shadowing attributes of the BIOS areas from 0E8000h–  
0EFFFFh.  
Bit  
Access &  
Default  
Description  
7:6  
5:4  
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.  
Reserved  
3:2  
1:0  
R/W  
00b  
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.  
82  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.25  
LAC—Legacy Access Control (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
97h  
00h  
R/W  
8 bits  
Size:  
This register controls a fixed DRAM hole from 15–16 MB.  
Bit  
Access  
&
Default  
Description  
7
R/W  
0 b  
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
Reserved  
R/W  
0 b  
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, 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, accesses to I/O address range  
x3BCh–x3BFh are forwarded to PCI Express*, if the address is within the  
corresponding IOBASE and IOLIMIT; otherwise, the accesses 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  
MDAP  
Description  
0
0
All References to MDA and VGA space are routed to the  
DMI  
0
1
1
0
Invalid combination  
All VGA and MDA references are routed to PCI Express  
graphics attach.  
1
1
All VGA references are routed to PCI Express graphics  
attach. MDA references are routed to the DMI  
VGA and MDA memory cycles can only be routed across the PCI Express when  
MAE (PCICMD1[1]) is set.  
VGA and MDA I/O cycles can only be routed across the PCI Express if IOAE  
(PCICMD1[0]) is set.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
83  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.26  
TOLUD—Top of Low Usable DRAM (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
9Ch  
08h  
R/W  
8 bits  
Size:  
This register defines the Top of Low usable DRAM. TSEG and graphics stolen memory are  
within the DRAM space defined. From the top of the DRAM space, the (G)MCH optionally  
claims 1 to 8 MBs of DRAM for internal graphics if enabled, and 1, 2, or 8 MB of DRAM for  
TSEG if enabled.  
Bit  
Access &  
Default  
Description  
7:3  
R/W  
01h  
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 of memory in the system plus one byte or  
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 intended for 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 memory is the lowest address above both graphics  
stolen memory 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 the base of  
TSEG.  
2:0  
Reserved  
Programming Example (82945G 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 1GB 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.  
84  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.27  
SMRAM—System Management RAM Control (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
9Dh  
02h  
R/W, RO, R/W/L  
8 bits  
Size:  
The SMRAMC register controls how accesses to compatible and extended SMRAM spaces are  
treated. The Open, Close, and Lock bits function only when the G_SMRAME bit is set to a 1.  
Also, the OPEN bit must be reset before the LOCK bit is set.  
Bit  
Access &  
Default  
Description  
7
6
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.  
5
4
R/W  
0b  
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.  
R/W/L  
0b  
SMM Space Locked (D_LCK): When D_LCK is set to 1, then 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.  
3
R/W/L  
0b  
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 9.4 for more details. Once  
D_LCK is set, this bit becomes read only.  
2:0  
RO  
010b  
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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
85  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.28  
ESMRAMC—Extended System Management RAM Control  
(D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
9Eh  
38h  
R/W/L, RO  
8 bits  
Size:  
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  
Description  
7
R/W/L  
0 b  
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=1 and  
H_SMRAME=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.  
6
R/WC  
0 b  
Invalid SMRAM Access (E_SMERR): This bit is set when the processor has  
accessed the defined memory ranges in Extended SMRAM (High Memory and  
TSEG) while not in SMM space and with D_OPEN = 0. It is software’s  
responsibility to clear this bit. Software must write a 1 to this bit to clear it.  
5
4
RO  
1 b  
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.  
RO  
1 b  
3
RO  
1 b  
2:1  
R/W/L  
00 b  
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.  
0
R/W/L  
0 b  
TSEG Enable (T_EN): Enabling of 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.  
86  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.29  
ERRSTS—Error Status (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
C8h  
0000h  
R/WC/S, RO  
16 bits  
Size:  
This register is used to report various error conditions via the SERR DMI messaging mechanism.  
A SERR DMI message is generated on a 0-to-1 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.  
Bit  
Access &  
Default  
Description  
15:13  
12  
Reserved  
R/WC/S  
0b  
(G)MCH Software Generated Event for SMI:  
1 = Source of the SMI was a Device 2 software event.  
(G)MCH Thermal Sensor Event for SMI/SCI/SERR:  
11  
R/WC/S  
0b  
1 =A (G)MCH Thermal Sensor trip has occurred and a SMI, SCI, or SERR has  
been generated. The status bit is set only if a message is sent based on  
Thermal event enables in the 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 Invalid). 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.  
10  
9
Reserved  
R/WC/S  
0b  
LOCK to non-DRAM Memory Flag (LCKF):  
1 =(G)MCH has detected a lock operation to memory space that did not map into  
DRAM.  
8
R/WC/S  
0b  
Received Refresh Timeout Flag(RRTOF):  
1 = 1024 memory core refreshes are enqueued.  
Reserved  
7:0  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
87  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.30  
ERRCMD—Error Command (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
CAh  
0000h  
R/W  
16 bits  
Size:  
This register controls the (G)MCH responses to various system errors. Since the (G)MCH does  
not have a SERR# signal, SERR messages are passed from the (G)MCH to the ICH7 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  
Description  
15:12  
11  
Reserved  
R/W  
0b  
SERR on (G)MCH Thermal Sensor Event (TSESERR)  
1 =Enable. The (G)MCH generates a DMI SERR special cycle when bit 11 of the  
ERRSTS register is set. The SERR must not be enabled at the same time as  
the SMI for the same thermal sensor event.  
0 =Disable. Reporting of this condition via SERR messaging is disabled.  
Reserved  
10  
9
R/W  
0b  
SERR on LOCK to non-DRAM Memory (LCKERR)  
1 =Enable. The (G)MCH will generate a DMI SERR special cycle when a  
processor lock cycle is detected that does not hit DRAM.  
0 =Disable. Reporting of this condition via SERR messaging is disabled.  
8
R/W  
0b  
SERR on DRAM Refresh Timeout (DRTOERR)  
1 =Enable. The (G)MCH generates a DMI SERR special cycle when a DRAM  
Refresh timeout occurs.  
0 =Disable. Reporting of this condition via SERR messaging is disabled.  
Reserved  
7:0  
88  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.1.31  
SKPD—Scratchpad Data (D0:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
0
DCh  
00000000h  
R/W  
Size:  
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  
Description  
31:0  
R/W  
Scratchpad Data: 1 DWord of data storage.  
00000000 h  
4.1.32  
CAPID0—Capability Identifier (D0:F0)  
PCI Device:  
0
Address Offset:  
Default Value:  
E0h  
82945G/82945GC/82945GZ GMCH:  
000000000001090009h  
82945P/82945PL MCH:  
000000000001090009h  
Access:  
Size:  
RO  
72 bits  
Bit  
Access &  
Default  
Description  
71:28  
27:24  
Reserved  
RO  
1h  
CAPID Version: This field has the value 0001b to identify the first revision of the  
CAPID register definition.  
23:16  
15:8  
7:0  
RO  
09h  
CAPID Length: This field has the value 09h to indicate the structure length  
(9 bytes).  
RO  
00h  
Next Capability Pointer: This field is hardwired to 00h indicating the end of the  
capabilities linked list.  
RO  
CAP_ID: This field has the value 1001b to identify the CAP_ID assigned by the  
09h  
PCI SIG for vendor dependent capability pointers.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
89  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2  
MCHBAR Register  
The MCHBAR registers are offset from the MCHBAR base address. Table 4-2 provides an  
address map of the registers listed by address offset in ascending order. Detailed register bit  
descriptions follow the table.  
Table 4-2. MCHBAR Register Address Map  
Address  
Offset  
Symbol  
Register Name  
Default  
Value  
Access  
100h  
101h  
C0DRB0  
C0DRB1  
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  
Channel A DRAM Rank 0,1 Attribute  
Channel A DRAM Rank 2,3 Attribute  
Channel A DRAM Clock Disable  
00h  
00h  
R/W  
R/W  
102h  
C0DRB2  
00h  
R/W  
103h  
C0DRB3  
00h  
R/W  
108h  
C0DRA0  
00h  
RO, R/W  
RO, R/W  
RO, R/W  
RO, R/W  
R/W, RO  
RO, R/W  
109h  
C0DRA2  
00h  
10Ch  
C0DCLKDIS  
C0BNKARC  
C0DRT1  
00h  
10E–10Fh  
114–117h  
120–123h  
Channel A DRAM Bank Architecture  
Channel A DRAM Timing Register 1  
Channel A DRAM Controller Mode 0  
0000h  
02903D22h  
C0DRC0  
4000280_  
00ssh  
124–127h  
180h  
C0DRC1  
C1DRB0  
C1DRB1  
C1DRB2  
C1DRB3  
C1DRA0  
C1DRA2  
C1DCLKDIS  
C1BNKARC  
C1DRT1  
Channel A DRAM Controller Mode 1  
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  
Channel B DRAM Rank 0,1 Attribute  
Channel B DRAM Rank 2,3 Attribute  
Channel B DRAM Clock Disable  
00000000h  
00h  
R/W  
R/W  
181h  
00h  
R/W  
182h  
00h  
R/W  
183h  
00h  
R/W  
188h  
00h  
RO, R/W  
RO, R/W  
RO, R/W/L  
RO, R/W  
RO  
189h  
00h  
18Ch  
00h  
18E–18Fh  
194–197h  
1A0–1A3h  
Channel B Bank Architecture  
0000h  
02903D22h  
Channel B DRAM Timing Register 1  
Channel B DRAM Controller Mode 0  
C1DRC0  
4000280_  
00ssh  
RO, R/W  
1A4–1A7h  
C1DRC1  
Channel B DRAM Controller Mode 1  
00000000h  
R/W, RO,  
R/W/L  
F10–F13h  
F14–F17h  
PMCFG  
PMSTS  
Power Management Configuration  
Power Management Status  
00000000h  
00000000h  
R/W, RO  
R/WC/S  
90  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.1  
C0DRB0—Channel A DRAM Rank Boundary Address 0  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
100h  
00h  
R/W  
Size:  
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: 100h  
Channel A Rank 1: 101h  
Channel A Rank 2: 102h  
Channel A Rank 3: 103h  
Channel B Rank 0: 180h  
Channel B Rank 1: 181h  
Channel B Rank 2: 182h  
Channel B Rank 3: 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.  
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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
91  
Host Bridge/DRAM Controller Registers (D0:F0)  
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)  
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 mode.  
Each Rank is represented by a byte. Each byte has the following format.  
Bit  
Access &  
Default  
Description  
7:0  
R/W  
00h  
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. For the 82945G and 82945P, bit 7 may be programmed to a 1 in the  
highest DRB (DRB3) if 4 GBs of memory are present.  
92  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.2  
4.2.3  
4.2.4  
C0DRB1—Channel A DRAM Rank Boundary Address 1  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
101h  
00h  
R/W  
Size:  
8 bits  
The operation of this register is detailed in the description for the C0DRB0 register.  
C0DRB2—Channel A DRAM Rank Boundary Address 2  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
102h  
00h  
R/W  
Size:  
8 bits  
The operation of this register is detailed in the description for the C0DRB0 register.  
C0DRB3—Channel A DRAM Rank Boundary Address 3  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
103h  
00h  
R/W  
Size:  
8 bits  
The operation of this register is detailed in the description for the C0DRB0 register.  
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Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.5  
C0DRA0—Channel A DRAM Rank 0,1 Attribute  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
108h  
00h  
R/W  
Size:  
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: 108h  
Channel A Rank 2, 3: 109h  
Channel B Rank 0, 1: 188h  
Channel B Rank 2, 3: 189h  
Bit  
Access &  
Default  
Description  
7
Reserved  
6:4  
R/W  
Channel A DRAM odd Rank Attribute: This 3-bit field defines the page size of  
000b  
the corresponding rank.  
000 = Unpopulated  
001 = Reserved  
010 = 4 KB  
011 = 8 KB  
100 = 16 KB  
Others = Reserved  
3
Reserved  
2:0  
R/W  
Channel A DRAM even Rank Attribute: This 3-bit field defines the page size of  
000b  
the corresponding rank.  
000 = Unpopulated  
001 = Reserved  
010 = 4 KB  
011 = 8 KB  
100 = 16 KB  
Others = Reserved  
4.2.6  
C0DRA2—Channel A DRAM Rank 2,3 Attribute  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
109h  
00h  
R/W  
Size:  
8 bits  
The operation of this register is detailed in the description for the C0DRA0 register.  
94  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.7  
C0DCLKDIS—Channel A DRAM Clock Disable  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
10Ch  
00h  
R/W  
Size:  
8 bits  
This register can be used to disable the system memory clock signals to each DIMM slot, which  
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.  
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.  
Bit  
Access &  
Default  
Description  
7:6  
5
Reserved  
R/W  
0b  
DIMM Clock Gate Enable Pair 5:  
0 = Tri-state the corresponding clock pair.  
1 = Enable the corresponding clock pair.  
4
3
2
1
0
R/W  
0b  
DIMM Clock Gate Enable Pair 4:  
0 = Tri-state the corresponding clock pair.  
1 = Enable the corresponding clock pair.  
R/W  
0b  
DIMM Clock Gate Enable Pair 3:  
0 = Tri-state the corresponding clock pair.  
1 = Enable the corresponding clock pair.  
R/W  
0b  
DIMM Clock Gate Enable Pair 2:  
0 = Tri-state the corresponding clock pair.  
1 = Enable the corresponding clock pair.  
R/W  
0b  
DIMM Clock Gate Enable Pair 1:  
0 = Tri-state the corresponding clock pair.  
1 = Enable the corresponding clock pair.  
R/W  
0b  
DIMM Clock Gate Enable Pair 0:  
0 = Tri-state the corresponding clock pair.  
1 = Enable the corresponding clock pair.  
Channel  
Rank  
Clocks Affected  
0
0
1
1
0 or 1  
2 or 3  
0 or 1  
2 or 3  
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]#  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
95  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.8  
C0BNKARC—Channel A DRAM Bank Architecture  
PCI Device:  
Function:  
MCHBAR  
0
Address Offset:  
Default Value:  
Access:  
10E–10Fh  
0000h  
R/W  
Size:  
16 bits  
This register is used to program the bank architecture for each rank.  
Bit  
Access &  
Default  
Description  
15:8  
7:6  
Reserved  
R/W  
00b  
Rank 3 Bank Architecture  
00 = 4 Bank.  
01 = 8 Bank.  
1X = Reserved  
5:4  
3:2  
1:0  
R/W  
00b  
Rank 2 Bank Architecture  
00 = 4 Bank.  
01 = 8 Bank.  
1X = Reserved  
R/W  
00b  
Rank 1 Bank Architecture  
00 = 4 Bank.  
01 = 8 Bank.  
1X = Reserved  
R/W  
00b  
Rank 0 Bank Architecture  
00 = 4 Bank.  
01 = 8 Bank.  
1X = Reserved  
96  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.9  
C0DRT1—Channel A DRAM Timing Register  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
114–117h  
02903D22h  
R/W  
Size:  
32 bits  
Bit  
Access &  
Default  
Description  
31:23  
22:19  
Reserved  
R/W  
9h  
Activate to Precharge delay (tRAS): This bit controls the number of DRAM  
clocks for tRAS. The minimum recommendations are beside their corresponding  
encodings.  
0h – 3h = Reserved  
4h – Fh = Four to fifteen clocks respectively.  
18:10  
9:8  
Reserved  
R/W  
01b  
CAS# 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.  
00 = 5  
01 = 4  
10 = 3  
11 = 6  
7
Reserved  
6:4  
R/W  
DRAM RAS to CAS Delay (tRCD): This bit controls the number of clocks inserted  
010b  
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 = 6 DRAM clocks  
101–111 = Reserved  
3
Reserved  
2:0  
R/W  
010b  
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 = 6 DRAM clocks  
101–111 = Reserved  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
97  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.10  
C0DRC0—Channel A DRAM Controller Mode 0  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
120–123h  
400028_00ssh (s = strap dependent)  
RO, R/W  
32 bits  
Size:  
Access &  
Default  
Bit  
Description  
31:30  
29  
01b  
Reserved  
R/W  
0b  
Initialization Complete (IC): This bit is used for communication of the software  
state between the memory controller and BIOS. BIOS sets this bit to 1 after  
initialization of the DRAM memory array is complete.  
28:11  
10:8  
00h  
Reserved  
R/W  
Refresh Mode Select (RMS): This field determines whether refresh is enabled  
000b  
and, if so, at what rate refreshes will be executed.  
000 = Refresh disabled  
001 = Refresh enabled. Refresh interval 15.6 usec  
010 = Refresh enabled. Refresh interval 7.8 usec  
011 = Refresh enabled. Refresh interval 3.9 usec  
100 = Refresh enabled. Refresh interval 1.95 usec  
111 = Refresh enabled. Refresh interval 64 clocks (fast refresh mode)  
Other = Reserved  
7
RO  
0b  
Reserved  
98  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
Access &  
Default  
Bit  
Description  
6:4  
R/W  
Mode Select (SMS): These bits select the special operational mode of the  
000b  
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, the (G)MCH  
will be reset, which will clear this bit field to 000 and maintain CKE signals  
de-asserted. After internal reset is de-asserted, the 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), the (G)MCH internal signal triggers the DRAM controller to flush  
pending commands and enter all ranks into Self-Refresh mode. During  
exit to normal mode, the (G)MCH signal triggers the DRAM controller to  
exit Self-Refresh and resume normal operation without software  
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,  
as shown in Volume 1, System Memory Controller section, memory  
Detection and Initialization. Refer to JEDEC Standard 79-2A Section 2.2.2  
“Programming the Mode and Extended Mode Registers”.  
100 = Extended Mode Register Set Enable – All processor cycles to DRAM  
result in an "extended mode register set" command on the DRAM  
interface. Host address lines are mapped to DRAM address lines in order  
to specify the command sent, as shown in Volume 1, System Memory  
Controller section, memory Detection and Initialization. Refer to JEDEC  
Standard 79-2A Section 2.2.2 “Programming the Mode and Extended  
Mode Registers”.  
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  
Reserved  
RO  
ss  
DRAM Type (DT): This field is used to select between supported SDRAM types.  
00 = Reserved  
01 = Reserved  
10 = Second Revision Dual Data Rate (DDR2) SDRAM  
11 = Reserved  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
99  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.11  
C0DRC1—Channel A DRAM Controller Mode 1  
Bus/Dev/Func/Type:  
Address Offset:  
Default Value:  
Access:  
0/0/0/MCHBAR  
124–127h  
00000000h  
R/W  
Size:  
32 bits  
Bit  
Access &  
Default  
Description  
31  
R/W  
0b  
Enhanced Addressing Enable (ENHADE):  
0 = Enhanced Addressing mode disabled. The DRAM address map follows the  
standard address map.  
1 = Enhanced Address mode enabled. The DRAM address map follows the  
enhanced address map.  
30:0  
Intel Reserved  
4.2.12  
4.2.13  
4.2.14  
C1DRB0—Channel B DRAM Rank Boundary Address 0  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
180h  
00h  
R/W  
Size:  
8 bits  
The operation of this register is detailed in the description for the C0DRB0 register.  
C1DRB1—Channel B DRAM Rank Boundary Address 1  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
181h  
00h  
R/W  
Size:  
8 bits  
The operation of this register is detailed in the description for the C0DRB0 register.  
C1DRB2—Channel B DRAM Rank Boundary Address 2  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
182h  
00h  
R/W  
Size:  
8 bits  
The operation of this register is detailed in the description for the C0DRB0 register.  
100  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.15  
C1DRB3—Channel B DRAM Rank Boundary Address 3  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
183h  
00h  
R/W  
Size:  
8 bits  
The operation of this register is detailed in the description for the C0DRB0 register.  
4.2.16  
4.2.17  
4.2.18  
4.2.19  
C1DRA0—Channel B DRAM Rank 0,1 Attribute  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
188h  
00h  
RO, R/W  
8 bits  
Size:  
The operation of this register is detailed in the description for the C0DRA0 register.  
C1DRA2—Channel B DRAM Rank 2,3 Attribute  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
189h  
00h  
R/W  
Size:  
8 bits  
The operation of this register is detailed in the description for the C0DRA0 register.  
C1DCLKDIS—Channel B DRAM Clock Disable  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
18Ch  
00h  
RO, R/W/L  
8 bits  
Size:  
The operation of this register is detailed in the description for the C0DCLKDIS register.  
C1BNKARC—Channel B Bank Architecture  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
18E–18Fh  
0000h  
RO, R/W  
16 bits  
Size:  
The operation of this register is detailed in the description for the C0BNKARC register.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
101  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.20  
4.2.21  
4.2.22  
4.2.23  
C1DRT1—Channel B DRAM Timing Register 1  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
194–197h  
02903D22h  
RO  
Size:  
32 bits  
The operation of this register is detailed in the description for the C0DRT1 register.  
C1DRC0—Channel B DRAM Controller Mode 0  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
1A0–1A3h  
4000280_00ssh (s = strap dependent)  
RO, R/W  
32 bits  
Size:  
The operation of this register is detailed in the description for the C0DRC0 register.  
C1DRC1—Channel B DRAM Controller Mode 1  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
MCHBAR  
1A4–1A7h  
00000000h  
RO, R/W, R/W/L  
32 bits  
Size:  
The operation of this register is detailed in the description for the C0DRC1 register.  
PMCFG—Power Management Configuration  
PCI Device:  
Address Offset:  
Default:  
Access:  
Size:  
MCHBAR  
F10–F13h  
00000000h  
RO, R/W  
32 bits  
Bit  
Access &  
Default  
Description  
31:5  
4
Reserved  
R/W  
0b  
Enhanced Power Management Features Enable:  
0 = Legacy power management mode  
1 = Reserved.  
3:0  
Reserved  
102  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.2.24  
PMSTS—Power Management Status  
PCI Device:  
Address Offset:  
Default:  
MCHBAR  
F14–F17h  
00h  
Access:  
Size:  
R/WC/S  
32 bits  
This register is reset by PWROK only.  
Bit  
Access &  
Default  
Description  
31:2  
1
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 Warm Reset  
sequence.  
This bit is cleared by power management hardware before starting Channel B  
self refresh exit sequence initiated by a power management exit.  
This bit is cleared by the BIOS in a warm reset (Reset# asserted while PWROK  
is asserted) exit sequence.  
0 = Channel B not ensured to be in self refresh.  
1 = Channel B in self refresh.  
0
R/WC/S  
0b  
Channel A in Self-refresh: This bit is 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.  
This bit is cleared by power management hardware before starting Channel A  
self refresh exit sequence initiated by a power management exit.  
This bit is cleared by the BIOS in a warm reset (Reset# asserted while PWROK  
is asserted) exit sequence.  
0 = Channel A not ensured to be in self refresh.  
1 = Channel A in self refresh.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
103  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.3  
EPBAR Registers—Egress Port Register Summary  
The MCHBAR registers are offset from the EPBAR base address. Table 4-3 provides an address  
map of the registers listed by address offset in ascending order. Detailed bit descriptions of the  
registers follow the table. Link Declaration Topology is shown in Figure 4-1.  
Table 4-3. Egress Port Register Address Map  
Address  
Symbol  
Offset  
Default  
Value  
Register Name  
Access  
044h–047h  
050h–053h  
EPESD  
EPLE1D  
EPLE1A  
EP Element Self Description  
EP Link Entry 1 Description  
EP Link Entry 1 Address  
00000201h  
01000000h  
R/WO, RO  
R/WO, RO  
R/WO, RO  
058h–  
05Fh  
000000000  
0000000h  
060h–063h  
EPLE2D  
EPLE2A  
EP Link Entry 2 Description  
EP Link Entry 2 Address  
02000002h  
R/WO, RO  
RO  
068h–  
06Fh  
000000000  
0008000h  
Figure 4-1. 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® ICH7  
Egress Port  
(Port #0)  
Egress_LinkDeclar_Topo  
104  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.3.1  
EPESD—EP Element Self Description  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
EPBAR  
044–047h  
00000201h  
RO, R/WO  
32 bits  
Size:  
This register provides information about the root complex element containing this Link  
Declaration Capability.  
Bit  
Access &  
Default  
Description  
31:24  
RO  
Port Number: This field specifies the port number associated with this element  
00h  
with respect to the component that contains this element.  
00h = Indicates to configuration software that this is the default egress port.  
23:16  
15:8  
R/WO  
00h  
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.  
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* and  
DMI).  
7:4  
3:0  
Reserved  
RO  
01h  
Element Type: This field indicates the type of the Root Complex Element.  
1h = Represents a port to system memory  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
105  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.3.2  
EPLE1D—EP Link Entry 1 Description  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
EPBAR  
050–053h  
01000000h  
RO, R/WO  
32 bits  
Size:  
This register provides the first part of a Link Entry that declares an internal link to another Root  
Complex Element.  
Bit  
Access &  
Default  
Description  
31:24  
RO  
01h  
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.  
23:16  
R/WO  
00h  
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
Reserved  
RO  
0b  
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.  
0
R/WO  
0b  
Link Valid:  
0 = Link Entry is not valid and will be ignored.  
1 = Link Entry specifies a valid link.  
106  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.3.3  
EPLE1A—EP Link Entry 1 Address  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
EPBAR  
058–05Fh  
00000000_00000000h  
R/WO  
Size:  
64 bits  
This register is the second part of a Link Entry that declares an internal link to another Root  
Complex Element.  
Bit  
Access &  
Default  
Description  
63:32  
31:12  
Reserved  
R/WO  
Link Address: This field provides the memory mapped base address of the  
0 0000h  
RCRB that is the target element (DMI) for this link entry.  
11:0  
Reserved  
4.3.4  
EPLE2D—EP Link Entry 2 Description  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
EPBAR  
060–63h  
02000002h  
RO, R/WO  
32 bits  
Size:  
This register provides the first part of a Link Entry that declares an internal link to another Root  
Complex Element.  
Bit  
Access &  
Default  
Description  
31:24  
RO  
02h  
Target Port Number: This field specifies the port number associated with the  
element targeted by this link entry (PCI Express). The target port number is with  
respect to the component that contains this element as specified by the target  
component ID.  
23:16  
R/WO  
00h  
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
Reserved  
RO  
1b  
Link Type: This bit indicates that the 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.  
0
R/WO  
0b  
Link Valid:  
0 = Link Entry is not valid and will be ignored.  
1 = Link Entry specifies a valid link.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
107  
Host Bridge/DRAM Controller Registers (D0:F0)  
4.3.5  
EPLE2A—EP Link Entry 2 Address  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
EPBAR  
068–06Fh  
0000000000008000h  
RO  
Size:  
64 bits  
This register is the second part of a Link Entry that declares an internal link to another Root  
Complex Element.  
Bit  
Access &  
Default  
Description  
63:28  
27:20  
Reserved  
RO  
Bus Number  
00h  
19:15  
14:12  
11:0  
RO  
0 0001b  
Device Number: Target for this link is PCI Express* x16 port (Device 1).  
RO  
000b  
Function Number  
Reserved  
§
108  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5 Host-PCI Express* Bridge  
Registers (D1:F0) (Intel®  
82945G/82945GC/82945P/82945PL  
Only)  
Device 1 contains 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 (PCI Express  
graphics) port. In addition, it also functions as the virtual PCI-to-PCI bridge. Table 5-1 provides  
an address map of the D1:F0 registers listed by address offset in ascending order. Section 5.1  
provides a detailed bit description of the registers.  
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 RW 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, which have historically been the typical definition for Reserved.  
Note: 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 5-1. Host-PCI Express* Graphics Bridge Register Address Map (D1:F0)  
Address  
Offset  
Default  
Value  
Symbol  
Register Name  
Access  
00–01h  
02–03h  
04–05h  
06–07h  
08h  
VID1  
DID1  
Vendor Identification  
8086h  
2771h  
0000h  
0010h  
RO  
RO  
Device Identification  
PCI Command  
PCICMD1  
PCISTS1  
RID1  
RO, R/W  
RO, R/W  
RO  
PCI Status  
Revision Identification  
See register  
description  
09–0Bh  
0Ch  
CC1  
CL1  
Class Code  
Cache Line Size  
Reserved  
060400h  
00h  
RO  
R/W  
0Dh  
0Eh  
HDR1  
Header Type  
01h  
RO  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
109  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
Address  
Offset  
Default  
Value  
Symbol  
Register Name  
Access  
0F–17h  
18h  
Reserved  
00h  
RO  
PBUSN1  
SBUSN1  
SUBUSN1  
Primary Bus Number  
Secondary Bus Number  
Subordinate Bus Number  
Reserved  
19h  
00h  
RO  
1Ah  
00h  
R/W  
1Bh  
1Ch  
IOBASE1  
IOLIMIT1  
SSTS1  
I/O Base Address  
F0h  
RO  
1Dh  
I/O Limit Address  
00h  
R/W  
1Eh–1Fh  
20–21h  
22–23h  
24–25h  
26–27h  
28–33h  
34h  
Secondary Status  
00h  
RO, R/WC  
R/W  
MBASE1  
MLIMIT1  
PMBASE1  
PMLIMIT1  
Memory Base Address  
Memory Limit Address  
Prefetchable Memory Base Address  
Prefetchable Memory Limit Address  
Reserved  
FFF0h  
0000h  
FFF0h  
0000h  
R/W  
RO, R/W  
RO, R/W  
CAPPTR1  
Capabilities Pointer  
88h  
RO  
35–3Bh  
3Ch  
Reserved  
INTRLINE1  
INTRPIN1  
BCTRL1  
Interrupt Line  
00h  
R/W  
3Dh  
Interrupt Pin  
01h  
RO  
3E–3Fh  
40–7Fh  
80–83h  
84–87h  
88–8Bh  
8C–8Fh  
90–91h  
Bridge Control  
0000h  
RO, R/W  
Reserved  
PM_CAP1  
PM_CS1  
SS_CAPID  
SS  
Power Management Capabilities  
Power Management Control/Status  
Subsystem ID and Vendor ID Capabilities  
Subsystem ID and Subsystem Vendor ID  
C8029001h  
00000000h  
0000800Dh  
00008086h  
A005h  
RO  
RO, R/W/S  
RO  
RO  
MSI_CAPID  
Message Signaled Interrupts Capability  
ID  
RO  
92–93h  
94–97h  
98–99h  
9A–9Fh  
A0–A1h  
A2–A3h  
A4–A7h  
A8–A9h  
AA–ABh  
AC–AFh  
B0–B1h  
B2–B3h  
B4–B7h  
B8–B9h  
BA–BBh  
MC  
MA  
Message Control  
Message Address  
Message Data  
Reserved  
0000h  
00000000h  
0000h  
RO, R/W  
RO, R/W  
R/W  
MD  
PEG_CAPL  
PEG_CAP  
DCAP  
PCI Express* Capability List  
PCI Express* Capabilities  
Device Capabilities  
Device Control  
Device Status  
0010h  
RO  
0141h  
RO  
00000000h  
0000h  
RO  
DCTL  
R/W  
DSTS  
0000h  
RO  
LCAP  
Link Capabilities  
Link Control  
02014D01h  
0000h  
R/WO  
RO, R/W  
RO  
LCTL  
LSTS  
Link Status  
1001h  
SLOTCAP  
SLOTCTL  
SLOTSTS  
Slot Capabilities  
Slot Control  
00000000h  
01C0h  
R/WO  
RO, R/W  
RO, R/WC  
Slot Status  
0000h  
110  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
Address  
Offset  
Default  
Value  
Symbol  
Register Name  
Access  
BC–BDh  
BE–BFh  
C0–C3h  
C4–FFh  
EC–EFh  
100–103h  
RCTL  
Root Control  
Reserved  
0000h  
R/W  
RSTS  
Root Status  
Reserved  
00000000h  
RO, R/WC  
PEG_LC  
VCECH  
PCI Express* Legacy Control  
00000000h  
14010002h  
R/W  
Virtual Channel Enhanced Capability  
Header  
RO  
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  
PVCCAP1  
PVCCAP2  
PVCCTL  
Port VC Capability Register 1  
Port VC Capability Register 2  
Port VC Control  
00000001h  
00000001h  
0000h  
RO, R/WO  
RO  
R/W  
Reserved  
VC0RCAP  
VC0RCTL  
VC0 Resource Capability  
VC0 Resource Control  
Reserved  
00000000h  
800000FFh  
RO  
RO, R/W  
VC0RSTS  
VC1RCAP  
VC1RCTL  
VC0 Resource Status  
VC1 Resource Capability  
VC1 Resource Control  
Reserved  
0002h  
RO  
00008000h  
01000000h  
RO  
RO, R/W  
VC1RSTS  
VC1 Resource Status  
Reserved  
0002h  
RO  
RCLDECH  
Root Complex Link Declaration  
Enhanced Capability Header  
00010005h  
RO  
144–147h  
148–14Fh  
150–153h  
154–157h  
158–15Fh  
ESD  
Element Self Description  
Reserved  
02000100h  
RO, R/WO  
00000000h  
LE1D  
Link Entry 1 Description  
Reserved  
RO, R/WO  
LE1A  
Link Entry 1 Address  
0000000000  
000000h  
R/WO  
160–1C5h  
1C4–1C7h  
1C8–1CBh  
1D0–1D3h  
1D4–1D3h  
1D4–1D7h  
1D8–217h  
218–21Fh  
UESTS  
UEMSK  
CESTS  
Reserved  
RO, R/WC/S  
RO, R/W/S  
RO, R/W/S  
Uncorrectable Error Status  
Uncorrectable Error Mask  
Correctable Error Status  
Reserved  
00000000h  
00000000h  
00000000h  
CEMSK  
Correctable Error Mask  
Reserved  
00000000h  
R/W/S  
PEG_SSTS  
PCI Express* Sequence Status  
0000000000  
000FFFh  
RO  
220–FFFh  
Reserved  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
111  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1  
Configuration Register Details (D1:F0)  
5.1.1  
VID1—Vendor Identification (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
00h  
8086h  
RO  
Size:  
16 bits  
This register, combined with the Device Identification register, uniquely identifies any PCI  
device.  
Bit  
Access &  
Default  
Description  
15:0  
RO  
Vendor Identification (VID1): This field provides the PCI standard identification for  
8086 h  
Intel.  
5.1.2  
DID1—Device Identification (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
02h  
2771h  
RO  
Size:  
16 bits  
This register, combined with the Vendor Identification register, uniquely identifies any PCI  
device.  
Bit  
Access &  
Default  
Description  
15:0  
RO  
Device Identification Number (DID1): This field is an identifier assigned to the  
2581h  
(G)MCH device 1 (virtual PCI-to-PCI bridge, PCI Express* graphics port).  
112  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.3  
PCICMD1—PCI Command (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
04h  
0000h  
RO, R/W  
16 bits  
Size:  
Bit  
Access &  
Default  
Description  
15:11  
10  
Reserved  
INTA Assertion Disable:  
R/W  
0b  
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.  
This bit only affects interrupts generated by the device (PCI INTA from a PME or  
Hot Plug event) controlled by this register. It does not affect upstream MSIs,  
upstream PCI INTA-INTD assert and de-assert messages.  
9
8
RO  
0b  
Fast Back-to-Back Enable (FB2B): Hardwired to 0. Not Applicable or  
Implemented.  
R/W  
0b  
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® ICH7. This bit, when set, enables reporting of non-  
fatal 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 =Disable. The SERR message is generated by the (G)MCH for Device 1 only  
under conditions enabled individually through the Device Control register.  
1 =Enable. The (G)MCH is enabled to generate SERR messages that will be  
sent to the ICH7 for specific Device 1 error conditions generated/detected 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
Reserved  
R/WO  
0b  
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 = Disable. Master Data Parity Error bit in PCI Status register cannot be set.  
1 = Enable. Master Data Parity Error bit in PCI Status register can be set.  
VGA Palette Snoop: Hardwired to 0. Not Applicable or Implemented.  
5
4
3
RO  
0b  
RO  
0b  
Memory Write and Invalidate Enable (MWIE): Hardwired to 0. Not Applicable or  
Implemented.  
RO  
0b  
Special Cycle Enable (SCE): Hardwired to 0. Not Applicable or Implemented.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
113  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
Bit  
Access &  
Default  
Description  
2
R/W  
0b  
Bus Master Enable (BME): This bit controls the ability of the PCI Express port to  
forward memory and I/O read/write requests in the upstream direction.  
0 = Disable. This device is prevented from making memory or I/O requests to its  
primary bus. Note that according to PCI Local Bus 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 invalid 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 = Enable. 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.  
This bit does not affect forwarding of completions from the primary interface to  
the secondary interface.  
1
0
R/W  
0b  
Memory Access Enable (MAE):  
0 = Disable. 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.  
R/W  
0b  
IO Access Enable (IOAE):  
0 = Disable. All of device 1’s I/O space is disabled.  
1 = Enable the I/O address range defined in the IOBASE1, and IOLIMIT1  
registers.  
114  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.4  
PCISTS1—PCI Status (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
06h  
0010h  
RO, R/WC  
16 bits  
Size:  
This register reports the occurrence of error conditions associated with the primary side of the  
“virtual” Host-PCI Express bridge in the (G)MCH.  
Bit  
Access &  
Default  
Description  
15  
RO  
0b  
Detected Parity Error (DPE): Hardwired to 0. Not Applicable or Implemented.  
Parity (generating poisoned TLPs) is not supported on the primary side of this  
device; the (G)MCH does Not do error forwarding.  
14  
R/WC  
0b  
Signaled System Error (SSE):  
1 =This Device sent a 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.  
13  
12  
RO  
0b  
Received Master Abort Status (RMAS): Hardwired to 0. Not Applicable or  
Implemented. The concept of a master abort does not exist on primary side of  
this device.  
RO  
0b  
Received Target Abort Status (RTAS): Hardwired to 0. Not Applicable or  
Implemented. The concept of a target abort does not exist on primary side of this  
device.  
11  
RO  
0b  
Signaled Target Abort Status (STAS): Hardwired to 0. Not Applicable or  
Implemented. The concept of a target abort does not exist on primary side of this  
device.  
10:9  
8
RO  
00b  
DEVSELB Timing (DEVT): This device is not the subtractive decoded device on  
bus 0. This bit field is therefore hardwired to 00 to indicate that the device uses  
the fastest possible decode.  
RO  
0b  
Master Data Parity Error (PMDPE): Because the primary side of the PCI  
Express’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 not 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,  
but for this implementation, a RO definition behaves the same way and will meet  
all Microsoft testing requirements.  
7
RO  
0b  
Fast Back-to-Back (FB2B): Hardwired to 0. Not Applicable or Implemented.  
6
5
Reserved  
RO  
0b  
66/60MHz capability (CAP66): Hardwired to 0. Not Applicable or Implemented.  
4
RO  
1b  
Capabilities List: Hardwired to 1. This indicates that a capabilities list is present.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
Bit  
Access &  
Default  
Description  
3
RO  
0b  
INTA Status:  
1 =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.  
2:0  
Reserved  
5.1.5  
RID1—Revision Identification (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
08h  
See bit description  
RO  
Size:  
8 bits  
This register contains the revision number of the (G)MCH device 1. These bits are read only and  
writes to this register have no effect.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Revision Identification Number (RID1): This field indicates the number of times  
that this device in this component has been “stepped” through the manufacturing  
process. It is always the same as the RID values in all other devices in this  
component. Refer to the Intel® 945G/945GC/945GZ/945P/945PL Express Chipset  
Specification Update for the value of the Revision ID register.  
5.1.6  
CC1—Class Code (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
09h  
060400h  
RO  
Size:  
24 bits  
This register identifies the basic function of the device, a more specific sub-class, and a register-  
specific programming interface.  
Bit  
Access &  
Default  
Description  
23:16  
RO  
06h  
Base Class Code (BCC): This field indicates the base class code for this device.  
06h = Bridge device.  
15:8  
7:0  
RO  
04h  
Sub-Class Code (SUBCC): This field indicates the sub-class code for this device.  
04h = PCI-to-PCI bridge.  
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.  
116  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.7  
CL1—Cache Line Size (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
0Ch  
00h  
R/W  
8 bits  
Size:  
Bit  
Access &  
Default  
Description  
7:0  
R/W  
00h  
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.  
5.1.8  
HDR1—Header Type (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
0Eh  
01h  
RO  
8 bits  
Size:  
This register identifies the header layout of the configuration space. No physical register exists at  
this location.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Header Type Register (HDR): This field returns 01h to indicate that this is a single  
01h  
function device with bridge header layout.  
5.1.9  
PBUSN1—Primary Bus Number (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
18h  
00h  
RO  
8 bits  
Size:  
This register identifies that this “virtual” Host-PCI Express bridge is connected to PCI bus 0.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
00h  
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 0s.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.10  
SBUSN1—Secondary Bus Number (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
19h  
00h  
RO  
8 bits  
Size:  
This register identifies the bus number assigned to the second bus side of the “virtual” bridge (i.e.,  
to PCI Express). This number is programmed by the PCI configuration software to allow mapping  
of configuration cycles to PCI Express.  
Bit  
Access &  
Default  
Description  
7:0  
R/W  
00h  
Secondary Bus Number (BUSN): This field is programmed by configuration  
software with the bus number assigned to PCI Express.  
5.1.11  
SUBUSN1—Subordinate Bus Number (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
1Ah  
00h  
R/W  
8 bits  
Size:  
This register identifies the subordinate bus (if any) that resides at the level below PCI Express.  
This number is programmed by the PCI configuration software to allow mapping of configuration  
cycles to PCI Express.  
Bit  
Access &  
Default  
Description  
7:0  
R/W  
00h  
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 segment, this register will contain the same value as the SBUSN1  
register.  
118  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.12  
IOBASE1—I/O Base Address (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
1Ch  
F0h  
RO  
8 bits  
Size:  
This register controls the processor-to-PCI Express 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  
Description  
7:4  
R/W  
Fh  
I/O Address Base (IOBASE): This field corresponds to A[15:12] of the I/O  
addresses passed by bridge 1 to PCI Express. BIOS must not set this register to  
00h; otherwise, 0CF8h/0CFCh accesses will be forwarded to the PCI Express  
hierarchy associated with this device.  
3:0  
Reserved  
5.1.13  
IOLIMIT1—I/O Limit Address (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
1Dh  
00h  
R/W  
8 bits  
Size:  
This register controls the processor-to-PCI Express 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 4-  
KB aligned address block.  
Bit  
Access &  
Default  
Description  
7:4  
R/W  
0h  
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.  
3:0  
Reserved  
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5.1.14  
SSTS1—Secondary Status (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
1Eh  
00h  
RO, R/WC  
16 bits  
Size:  
SSTS1 is a 16-bit status register that reports the occurrence of error conditions associated with the  
secondary side (i.e., PCI Express side) of the “virtual” PCI-PCI Bridge in the (G)MCH.  
Bit  
Access &  
Default  
Description  
15  
R/WC  
0b  
Detected Parity Error (DPE):  
0 =Parity error Not detected.  
1 =The (G)MCH received across the link (upstream) a Posted Write Data  
Poisoned TLP (EP=1).  
14  
13  
12  
R/WC  
0b  
Received System Error (RSE):  
0 =System error Not received.  
1 =The secondary side sent 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.  
R/WC  
0b  
Received Master Abort (RMA):  
0 =Master abort Not received.  
1 =The 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.  
R/WC  
0b  
Received Target Abort (RTA):  
0 =Target abort Not received.  
1 =The 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.  
11  
RO  
0b  
Signaled Target Abort (STA): Hardwired to 0. Not Applicable or Implemented.  
The (G)MCH does not generate Target Aborts (the (G)MCH will never complete  
a request using the Completer Abort completion status).  
10:9  
RO  
DEVSELB Timing (DEVT): Hardwired to 0. Not Applicable or Implemented.  
00b  
8
7
Reserved  
RO  
0b  
Fast Back-to-Back (FB2B): Hardwired to 0. Not Applicable or Implemented.  
6
5
Reserved  
RO  
0b  
66/60 MHz capability (CAP66): Hardwired to 0. Not Applicable or Implemented.  
4:0  
Reserved  
120  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.15  
MBASE1—Memory Base Address (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
20h  
FFF0h  
R/W  
16 bits  
Size:  
This register controls the processor-to-PCI Express 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  
15:4  
3:0  
Access &  
Default  
Description  
R/W  
FFFh  
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  
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121  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.16  
MLIMIT1—Memory Limit Address (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
22h  
0000h  
R/W  
16 bits  
Size:  
This register controls the processor-to-PCI Express 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 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-pre-fetchable PCI  
Express 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 pre-fetchable  
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 pre-fetchable address range for improved processor -PCI Express memory  
access performance.  
Note: Configuration software is responsible for programming all address range registers (pre-fetchable,  
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 may be affected.  
Bit  
15:4  
3:0  
Access &  
Default  
Description  
R/W  
000h  
Memory Address Limit (MLIMIT): This field corresponds to A[31:20] of the  
upper limit of the address range passed to PCI Express.  
Reserved  
122  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.17  
PMBASE1—Prefetchable Memory Base Address (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
24h  
FFF0h  
RO, R/W  
16 bits  
Size:  
This register, in conjunction with the corresponding Upper Base Address register, controls the  
processor-to-PCI Express 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  
40-bit 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  
Description  
15:4  
R/W  
FFFh  
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.  
3:0  
RO  
0h  
64-bit Address Support: This field indicates the bridge supports only 32-bit  
address support.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.18  
PMLIMIT1—Prefetchable Memory Limit Address (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
26h  
0000h  
RO, R/W  
16 bits  
Size:  
This register, in conjunction with the corresponding Upper Limit Address register, controls the  
processor-to-PCI Express 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 40-  
bit 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  
15:4  
3:0  
Access &  
Default  
Description  
R/W  
000h  
Prefetchable Memory Address Limit (PMLIMIT): This field corresponds to  
A[31:20] of the upper limit of the address range passed to PCI Express.  
RO  
0h  
64-bit Address Support: This field indicates the bridge only supports 32-bit  
addresses.  
5.1.19  
CAPPTR1—Capabilities Pointer (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
34h  
88h  
RO  
8 bits  
Size:  
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  
Description  
7:0  
RO  
First Capability (CAPPTR1): The first capability in the list is the Subsystem ID  
88h  
and Subsystem Vendor ID Capability.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.20  
INTRLINE1—Interrupt Line (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
3Ch  
00h  
R/W  
8 bits  
Size:  
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  
Description  
7:0  
R/W  
00h  
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 is connected to this device’s interrupt pin.  
5.1.21  
INTRPIN1—Interrupt Pin (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
3Dh  
01h  
RO  
8 bits  
Size:  
This register specifies which interrupt pin this device uses.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Interrupt Pin: As a single function device, the PCI Express device specifies  
01h  
INTA as its interrupt pin.  
01h=INTA.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.22  
BCTRL1—Bridge Control (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
3Eh  
0000h  
RO, R/W  
16 bits  
Size:  
This register provides extensions to the PCICMD1 register that are specific to PCI-to-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-to-PCI Express bridge in  
the (G)MCH (e.g., VGA compatible address ranges mapping).  
Bit  
Access &  
Default  
Description  
15:12  
11  
Reserved  
RO  
0b  
Discard Timer SERR Enable: Hardwired to 0. Not Applicable or Implemented.  
Discard Timer Status: Hardwired to 0. Not Applicable or Implemented.  
Secondary Discard Timer: Hardwired to 0. Not Applicable or Implemented.  
Primary Discard Timer: Hardwired to 0. Not Applicable or Implemented.  
10  
9
RO  
0b  
RO  
0b  
8
RO  
0b  
7
RO  
0b  
Fast Back-to-Back Enable (FB2BEN): Hardwired to 0. Not Applicable or  
Implemented.  
6
R/W  
0b  
Secondary Bus Reset (SRESET):  
0 = Hot reset not triggered on the corresponding PCI Express port.  
1 = Setting this bit triggers a hot reset on the corresponding PCI Express port.  
5
4
RO  
0b  
Master Abort Mode (MAMODE): Hardwired to 0. When acting as a master,  
unclaimed reads that experience a master abort return all 1s and any writes that  
experience a master abort complete normally and the data is discarded.  
R/W  
0b  
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 the LAC Register[0] (Device 0, offset 97h).  
126  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
Bit  
Access &  
Default  
Description  
2
R/W  
0b  
ISA Enable (ISAEN): This bit is used to exclude legacy resource decode to route  
ISA resources to the 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.  
1 =(G)MCH will not forward to PCI Express 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, these cycles are forwarded to DMI where they can be subtractively  
or positively claimed by the ISA bridge.  
1
0
R/W  
0b  
SERR Enable (SERREN):  
0 =Disable. No forwarding of error messages from secondary side to primary  
side that could result in a SERR.  
1 =Enable. ERR_COR, ERR_NONFATAL, and ERR_FATAL messages result in  
SERR message when individually enabled by the Root Control register.  
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  
(G)MCH receives across the link (upstream) a Read Data Completion Poisoned  
TLP.  
0 =Disable. Master Data Parity Error bit in Secondary Status register cannot be  
set.  
1 =Enable. Master Data Parity Error bit in Secondary Status register can be set.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.23  
PM_CAPID1—Power Management Capabilities (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
80h  
C8029001h  
RO  
Size:  
32 bits  
Bit  
Access &  
Default  
Description  
31:27  
RO  
19h  
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  
Interface Specification, Revision 1.1 for encoding explanation and other power  
management details.  
26  
25  
RO  
0b  
D2: Hardwired to 0 to indicate that the D2 power management state is NOT  
supported.  
RO  
0b  
D1: Hardwired to 0 to indicate that the D1 power management state is NOT  
supported.  
24:22  
21  
RO  
000b  
Auxiliary Current: Hardwired to 0 to indicate that there are no 3.3Vaux auxiliary  
current requirements.  
RO  
0b  
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.  
20  
19  
RO  
0b  
Auxiliary Power Source (APS): Hardwired to 0.  
RO  
0b  
PME Clock: Hardwired to 0 to indicate this device does NOT support PME#  
generation.  
18:16  
RO  
010b  
PCI PM CAP Version: Hardwired to 02h to indicate there are 4 bytes of power  
management registers implemented and that this device complies with the PCI  
Power Management Interface Specification, Revision 1.1.  
15:8  
7:0  
RO  
90h / A0h  
Pointer to Next Capability: This filed contains a pointer to the next item in the  
capabilities list. If MSICH (CAPL[0] @ 7Fh) is 0, the next item in the capabilities  
list is the Message Signaled Interrupts (MSI) capability at 90h. If MSICH  
(CAPL[0] @ 7Fh) is 1, the next item in the capabilities list is the PCI Express  
capability at A0h.  
RO  
Capability ID: The value of 01h identifies this linked list item (capability structure)  
01h  
as being for PCI Power Management registers.  
128  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.24  
PM_CS1—Power Management Control/Status (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
84–87h  
00000000h  
RO, R/W/S  
32 bits  
Size:  
Bit  
Access &  
Default  
Description  
31:16  
15  
Reserved  
PME Status: This bit indicates that this device does not support PME#  
RO  
0b  
generation from D3  
.
cold  
14:13  
12:9  
8
RO  
00b  
Data Scale: This field indicates that this device does not support the Power  
Management Data register.  
RO  
0h  
Data Select: This field indicates that this device does not support the Power  
Management Data register.  
R/W/S  
0b  
PME Enable: This bit indicates that this device does not generate PME#  
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]  
Reserved  
7:2  
1:0  
R/W  
00b  
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.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.25  
SS_CAPID—Subsystem ID and Vendor ID Capabilities  
(D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
88h  
0000800Dh  
RO  
Size:  
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  
as part of its compliance testing.  
Bit  
Access &  
Default  
Description  
31:16  
15:8  
Reserved  
RO  
Pointer to Next Capability: This field contains a pointer to the next item in the  
80h  
capabilities list that is the PCI Power Management capability.  
7:0  
RO  
Capability ID: The value of 0Dh identifies this linked list item (capability  
0Dh  
structure) as being for SSID/SSVID registers in a PCI-to-PCI Bridge.  
5.1.26  
SS—Subsystem ID and Subsystem Vendor ID (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
8Ch  
00008086h  
RO  
Size:  
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  
Description  
31:16  
15:0  
R/WO  
0000h  
Subsystem ID (SSID): This field identifies the particular subsystem and is  
assigned by the vendor.  
R/WO  
8086h  
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.  
130  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.27  
MSI_CAPID—Message Signaled Interrupts Capability ID  
(D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
90h  
A005h  
RO  
Size:  
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] @  
7Fh). In that case going through this linked list will skip this capability and instead go directly  
from the PCI PM capability to the PCI Express capability.  
Bit  
15:8  
7:0  
Access &  
Default  
Description  
RO  
A0h  
Pointer to Next Capability: This field contains a pointer to the next item in the  
capabilities list which is the PCI Express capability.  
RO  
Capability ID: The value of 05h identifies this linked list item (capability  
05h  
structure) as being for MSI registers.  
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131  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.28  
MC—Message Control (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
92h  
0000h  
RO, R/W  
16 bits  
Size:  
System software can modify bits in this register, but the device is prohibited from doing  
modifying the bits.  
If the device writes the same message multiple times, only one of those messages is ensured to be  
serviced. If all of them must be serviced, the device must not generate the same message again  
until the driver services the previous one(s).  
Bit  
Access &  
Default  
Description  
15:8  
7
Reserved  
RO  
0b  
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.  
6:4  
3:1  
R/W  
000b  
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. The encoding is the  
same as for the MMC field (Bits 3:1).  
RO  
Multiple Message Capable (MMC): System software reads this field to  
000b  
determine the number of messages being requested by this device.  
000 = 1  
001–111 = Reserved  
0
R/W  
0b  
MSI Enable (MSIEN): This bit controls the ability of this device to generate MSIs.  
0 =Disable. MSI will not be generated.  
1 =Enable. MSI will be generated when (G)MCH receive PME or HotPlug  
messages. INTA will not be generated and INTA Status (PCISTS1[3]) will not  
be set.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.29  
MA—Message Address (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
94h  
00000000h  
RO, R/W  
32 bits  
Size:  
Bit  
Access &  
Default  
Description  
31:2  
R/W  
00000000h  
Message Address: This field is used by system software to assign a MSI  
address to the device. The device handles a MSI by writing the padded  
contents of the MD register to this address.  
1:0  
RO  
Force DWord Align: Hardwired to 0s so that addresses assigned by system  
00b  
software are always aligned on a DWord address boundary.  
5.1.30  
MD—Message Data (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
98–99h  
0000h  
R/W  
Size:  
16 bits  
Bit  
Access &  
Default  
Description  
15:0  
R/W  
Message Data: This field is the base message data pattern assigned by system  
0000h  
software and used to handle a 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.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.31  
PEG_CAPL—PCI Express* Capability List (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
A0–A1h  
0010h  
RO  
Size:  
16 bits  
This register enumerates the PCI Express capability structure.  
Bit  
Access &  
Default  
Description  
15:8  
RO  
00h  
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.  
7:0  
RO  
Capability ID: This field identifies this linked list item (capability structure) as  
10h  
being for PCI Express registers.  
5.1.32  
PEG_CAP—PCI Express* Capabilities (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
A2–A3h  
0141h  
RO, R/WO  
16 bits  
Size:  
This register indicates PCI Express device capabilities.  
Bit  
Access &  
Default  
Description  
15:14  
13:9  
Reserved  
RO  
Interrupt Message Number: Hardwired to 0. Not Applicable or Implemented.  
00h  
8
R/WO  
1b  
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  
Device/Port Type: Hardwired to 4h to indicate root port of PCI Express Root  
Complex.  
RO  
1h  
PCI Express Capability Version: Hardwired to 1h as it is the first version.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.33  
DCAP—Device Capabilities (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
A4–A7h  
00000000h  
RO  
Size:  
32 bits  
This register indicates PCI Express link capabilities.  
Bit  
Access &  
Default  
Description  
31:6  
5
Reserved  
RO  
0b  
Extended Tag Field Supported: Hardwired to indicate support for 5-bit tags as a  
requestor.  
4:3  
2:0  
RO  
00b  
Phantom Functions Supported: Hardwired to 0. Not Applicable or Implemented.  
RO  
Max Payload Size: Hardwired to indicate 128 Byte maximum supported payload  
000b  
for Transaction Layer Packets (TLP).  
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135  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.34  
DCTL—Device Control (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
A8–A9h  
0000h  
R/W  
Size:  
16 bits  
This register provides control for PCI Express device specific capabilities.  
Note: 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 the Root  
Port Command register.  
Bit  
Access &  
Default  
Description  
15:8  
7:5  
Reserved  
R/W  
Max Payload Size:  
000b  
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  
a transmitter, the Device must not generate TLPs exceeding the set  
value.  
001–111 = Reserved.  
4
3
Reserved  
R/W  
0b  
Unsupported Request Reporting Enable:  
0 = Disable.  
1 = Enable. Unsupported requests will be reported.  
NOTE: Reporting of error messages received by Root Port is controlled  
exclusively by Root Control register.  
2
1
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.  
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.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.35  
DSTS—Device Status (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
AAh  
0000h  
RO  
Size:  
16 bits  
This register reflects the 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  
Description  
15:6  
5
Reserved  
RO  
0b  
Transactions Pending:  
0 = All pending transactions (including completions for any outstanding non-  
posted 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
Reserved  
R/WC  
0b  
Unsupported Request Detected:  
0 = Unsupported Request Not 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.  
2
1
0
R/WC  
0b  
Fatal Error Detected: When Advanced Error Handling is enabled, errors are  
logged in this register regardless of the settings of the Correctable Error Mask  
register.  
0 = Fatal Error Not detected.  
1 = Fatal error(s) detected. Errors are logged in this register regardless of  
whether error reporting is enabled or not in the Device Control register.  
R/WC  
0b  
Non-Fatal Error Detected: When Advanced Error Handling is enabled, errors are  
logged in this register regardless of the settings of the Correctable Error Mask  
register.  
0 = Non-fatal error Not detected.  
1 = Non-fatal error(s) detected. Errors are logged in this register regardless of  
whether error reporting is enabled or not in the Device Control register.  
R/WC  
0b  
Correctable Error Detected: When Advanced Error Handling is enabled, errors  
are logged in this register regardless of the settings of the Correctable Error Mask  
register.  
0 = Correctable error Not detected.  
1 = Correctable error(s) detected. Errors are logged in this register regardless of  
whether error reporting is enabled or not in the Device Control register.  
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137  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.36  
LCAP—Link Capabilities (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
AC–AF  
02014D01h  
R/WO, RO  
16 bits  
Size:  
This register indicates PCI Express device specific capabilities.  
Bit  
Access &  
Default  
Description  
31:24  
RO  
Port Number: This field indicates the PCI Express* port number for the given PCI  
02h  
Express link. It matches the value in Element Self Description [31:24].  
23:15  
14:12  
Reserved  
R/WO  
100b  
L0s Exit Latency: This field indicates the length of time this port requires to  
complete the transition from L0s to L0. The value 100b indicates the range of  
256 ns to less than 512 ns. If this field is required to be any value other than the  
default, BIOS must initialize it accordingly.  
11:10  
RO  
Active State Link PM Support: L0s and L1 entry supported.  
11b  
NOTE: L1 state is Not supported on the 82945G/82945GC/82945GZ GMCH and  
82945P/82945PL MCH.  
9:4  
3:0  
RO  
10h  
Max Link Width: Hardwired to indicate X16. When Force X1 mode is enabled on  
this PCI Express device, this field reflects X1 (01h).  
RO  
1h  
Max Link Speed: Hardwired to indicate 2.5 Gb/s.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.37  
LCTL—Link Control (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
B0–B1  
0000h  
RO, R/W  
16 bits  
Size:  
This register allows control of the PCI Express link.  
Bit  
Access &  
Default  
Description  
15:8  
7
Reserved  
R/W  
0h  
Reserved. Must be 0 when writing this register.  
6
R/W  
0b  
Common Clock Configuration: Components use this common clock  
configuration information to report the correct L0s exit latency.  
The state of this bit affects the L0s exit latency reported in LCAP [14:12] and the  
N_FTS value advertised during link training.  
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.  
5
4
R/W  
0b  
Retrain Link: This bit always returns 0 when read. This bit is cleared  
automatically (no need to write a 0).  
0 = Normal operation  
1 = Full Link retraining is initiated by directing the Physical Layer LTSSM from L0  
or L0s states to the recovery state.  
R/W  
0b  
Link Disable: The link retraining happens automatically on a 0-to-1 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.  
0 = Enable. Normal operation  
1 = Link is disabled. This forces the LTSSM to transition to the disabled state (via  
Recovery) from L0 or L0s states.  
3
RO  
0b  
Read Completion Boundary (RCB) : Hardwired to 0 to indicate 64 byte.  
2
Reserved  
1:0  
R/W  
00b  
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 Entry Supported  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.38  
LSTS—Link Status (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
B2–B3h  
1001h  
RO  
Size:  
16 bits  
This register indicates PCI Express link status.  
Bit  
Access &  
Default  
Description  
15:13  
12  
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  
10  
RO  
0b  
Link Training: Hardware clears this bit once link training is complete.  
0 = Link training Not in progress.  
1 = Link training is in progress.  
RO  
0b  
Training Error:  
0 = No training error  
1 = Set by hardware upon detection of unsuccessful training of the link to the L0  
Link state.  
9:4  
RO  
Negotiated Width: This field indicates negotiated link width.  
00h  
00h = Reserved  
01h = X1  
04h = Reserved  
08h = Reserved  
10h = X16  
All other encodings are reserved.  
Negotiated Speed: This field indicates negotiated link speed.  
1h = 2.5 Gb/s  
3:0  
RO  
1h  
All other encodings are reserved.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.39  
SLOTCAP—Slot Capabilities (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
B4–B7h  
00000000h  
R/WO  
32 bits  
Size:  
PCI Express slot-related registers allow for the support of Hot-Plug.  
Bit  
Access &  
Default  
Description  
31:19  
R/WO  
0000h  
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  
Reserved  
R/WO  
00b  
Slot Power Limit Scale: This field specifies the scale used for the Slot Power  
Limit value. If this field is written, the link sends a Set_Slot_Power_Limit  
message.  
00 = 1.0x  
01 = 0.1x  
10 = 0.01x  
11 = 0.001x  
14:7  
R/WO  
00h  
Slot Power Limit Value: This field, in combination with the Slot Power Limit  
Scale value, specifies the upper limit on power supplied by the 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
R/WO  
0b  
Hot-plug Capable: This bit indicates that this slot is capable of supporting hot-  
plug operations.  
0 = Not capable  
1 =Capable.  
R/WO  
0b  
Hot-plug Surprise: This bit indicates that a device present in this slot might be  
removed from the system without any prior notification.  
0 = No hot-plug surprise  
1 = Hot plug Surprise capable.  
R/WO  
0b  
Power Indicator Present: This bit indicates that a power indicator is  
implemented on the chassis for this slot.  
0 = Not present  
1 = Present  
R/WO  
0b  
Attention Indicator Present: This bit indicates that an Attention Indicator is  
implemented on the chassis for this slot.  
0 = Not present  
1 = Present  
2:1  
0
Reserved  
R/WO  
0b  
Attention Button Present: This bit indicates that an attention button is  
implemented on the chassis for this slot. The attention button allows the user to  
request hot-plug operations.  
0 = Not present  
1 = Present  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.40  
SLOTCTL—Slot Control (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
B8h  
01C0h  
R/W  
16 bits  
Size:  
PCI Express slot related registers allow for the support of hot-plug.  
Bit  
Access &  
Default  
Description  
15:10  
9:8  
Reserved  
R/W  
01b  
Power Indicator Control: Reads to this field return the current state of the  
power indicator. Writes to this field 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  
11 b  
Attention Indicator Control: Reads to this field return the current state of the  
attention indicator. Writes to this field set the attention indicator and cause the  
port to send the appropriate ATTENTION_INDICATOR_* messages.  
00 = Reserved  
01 = On  
10 = Blink  
11 = Off  
5
4
R/W  
0b  
Hot plug Interrupt Enable:  
0 =Disable.  
1 = Enables generation of hot plug interrupt on enabled hot plug events.  
Command Completed Interrupt Enable:  
0 = Disable.  
R/W  
0b  
1 = Enables the generation of a 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 a hot-plug interrupt or wake message on a  
presence detect changed event.  
2:1  
0
Reserved  
R/W  
0b  
Attention Button Pressed Enable:  
0 = Disable.  
1 = Enables the generation of hot-plug interrupt or wake message on an  
attention button pressed event.  
142  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.41  
SLOTSTS—Slot Status (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
BA–BBh  
0000h  
RO, R/WC  
16 bits  
Size:  
PCI Express slot-related registers allow for the support of hot-plug.  
Bit  
Access &  
Default  
Description  
15:7  
6
Reserved  
RO  
Strap  
Presence Detect State: This bit indicates the presence of a card in the slot.  
0 = Slot Empty  
1 = Card Present in slot.  
5
4
Reserved  
R/WC  
0b  
Command Completed:  
0 = Command Not completed.  
1 = Hot-plug controller completes an issued command.  
Presence Detect Changed:  
3
R/WC  
0b  
0 =No Presence Detect change.  
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).  
2:1  
0
Reserved  
R/WC  
0b  
Attention Button Pressed:  
0 = Attention button Not pressed.  
1 = Attention button is pressed.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
143  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.42  
RCTL—Root Control (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
BCh  
0000h  
R/W  
16 bits  
Size:  
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 the 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  
Description  
15:4  
3
Reserved  
R/W  
0b  
PME Interrupt Enable:  
0 = Disable. 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
1
0
R/W  
0b  
System Error on Fatal Error Enable: This bit controls the root complex’s  
response to fatal errors.  
0 = Disable. No SERR generated on receipt of fatal error.  
1 = SERR is 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.  
R/W  
0b  
System Error on Non-Fatal Uncorrectable Error Enable: This bit controls the  
Root Complex’s response to non-fatal errors.  
0 = Disable. No SERR generated on receipt of non-fatal error.  
1 = SERR is 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.  
R/W  
0b  
System Error on Correctable Error Enable: This bit controls the Root  
Complex’s response to correctable errors.  
0 = Disable. No SERR generated on receipt of correctable error.  
1 = SERR is 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.  
144  
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5.1.43  
RSTS—Root Status (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
C0–C3h  
00000000h  
RO, R/WC  
32 bits  
Size:  
This register provides information about PCI Express Root Complex specific parameters.  
Bit  
Access &  
Default  
Description  
31:18  
17  
Reserved  
RO  
0b  
PME Pending:  
0 = PME Not pending.  
1 = 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.  
16  
R/WC  
0b  
PME Status:  
0 = Requestor ID did Not assert PME.  
1 = 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.  
15:0  
RO  
PME Requestor ID: This field indicates the PCI requestor ID of the last PME  
0000h  
requestor.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
145  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.44  
PEG_LC—PCI Express* Legacy Control (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
EC–EFh  
00000000h  
R/W  
Size:  
32 bits  
This register controls functionality that is needed by legacy (non-PCI Express aware) operating  
systems during run time.  
Bit  
Access &  
Default  
Description  
31:3  
2
Reserved  
R/W  
0b  
PME GPE Enable (PMEGPE):  
0 = Disable. 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* port under legacy  
operating systems.  
1
R/W  
0b  
Hot-Plug GPE Enable (HPGPE):  
0 = Disable. Do Not generate GPE hot-plug message when a hot-plug event is  
received.  
1 = Enable. Generate a GPE hot-plug message when a 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 port under legacy operating  
systems.  
0
R/W  
0b  
General Message GPE Enable (GENGPE):  
0 = Disable. Do Not forward received GPE assert/de-assert messages.  
1 = Enable. Forward received GPE assert/de-assert messages. These general  
GPE message can be received via the PCI Express port from an external  
Intel device and will be subsequently forwarded to the Intel® ICH7 (via  
Assert_GPE and Deassert_GPE messages on DMI).  
146  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.45  
VCECH—Virtual Channel Enhanced Capability Header  
(D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
100–103h  
14010002h  
RO  
Size:  
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  
Description  
31:20  
19:16  
15:0  
RO  
140h  
Pointer to Next Capability: The Link Declaration Capability is the next in the PCI  
Express* extended capabilities list.  
RO  
1h  
PCI Express Virtual Channel Capability Version: Hardwired to 1 to indicate  
compliances with the PCI Express specification, Revsion 1.0a.  
RO  
Extended Capability ID: A value of 0002h identifies this linked list item  
0002h  
(capability structure) as being for PCI Express Virtual Channel registers.  
5.1.46  
PVCCAP1—Port VC Capability Register 1 (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
104h  
00000001h  
RO, R/WO  
32 bits  
Size:  
This register describes the configuration of PCI Express Virtual Channels associated with this  
port.  
Bit  
Access &  
Default  
Description  
31:7  
6:4  
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.  
Reserved  
3
2:0  
R/WO  
001b  
Extended VC Count: This field indicates the number of (extended) Virtual  
Channels in addition to the default VC supported by the device.  
BIOS Requirement: Set this field to 000b for all configurations.  
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5.1.47  
PVCCAP2—Port VC Capability Register 2 (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
108–10Bh  
00000001h  
RO  
Size:  
32 bits  
This register describes the configuration of PCI Express Virtual Channels associated with this  
port.  
Bit  
Access &  
Default  
Description  
31:24  
RO  
00h  
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).  
23:8  
7:0  
Reserved  
RO  
VC Arbitration Capability: This field indicates that the only possible VC  
01h  
arbitration scheme is hardware fixed (in the root complex).  
VC1 is the highest priority, VC0 is the lowest priority.  
5.1.48  
PVCCTL—Port VC Control (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
10C–10Dh  
0000h  
R/W  
Size:  
16 bits  
Bit  
Access &  
Default  
Description  
15:4  
3:1  
Reserved  
R/W  
000b  
VC Arbitration Select: This field is programmed by software to the only possible  
value as indicated in the VC Arbitration Capability field. The value 001b, when  
written to this field, indicates 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  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.49  
VC0RCAP—VC0 Resource Capability (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
110–113h  
00000000h  
RO  
Size:  
32 bits  
Bit  
Access &  
Default  
Description  
31:16  
15  
Reserved  
Reject Snoop Transactions  
RO  
0b  
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  
5.1.50  
VC0RCTL—VC0 Resource Control (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
114–117h  
800000FFh  
RO, R/W  
32 bits  
Size:  
This register controls the resources associated with PCI Express Virtual Channel 0.  
Bit  
Access &  
Default  
Description  
31  
RO  
1b  
VC0 Enable: For VC0, this bit is hardwired to 1 and read only as VC0 can never  
be disabled.  
30:27  
26:24  
Reserved  
RO  
VC0 ID: This field assigns a VC ID to the VC resource. For VC0, this is hardwired  
000b  
to 0 and read only.  
23:8  
7:1  
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. 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.  
0
RO  
1b  
TC0/VC0 Map: Traffic Class 0 is always routed to VC0.  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.51  
VC0RSTS—VC0 Resource Status (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
11A–11Bh  
0002h  
RO  
Size:  
16 bits  
This register reports the Virtual Channel specific status.  
Bit  
Access &  
Default  
Description  
15:2  
1
Reserved  
RO  
1b  
VC0 Negotiation Pending: 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.  
0 = The VC negotiation is complete.  
1 = The VC resource is still in the process of negotiation (initialization or  
disabling).  
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  
5.1.52  
VC1RCAP—VC1 Resource Capability (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
11C–11Fh  
00008000h  
RO  
Size:  
32 bits  
Bit  
Access &  
Default  
Description  
31:16  
15  
Reserved  
Reject Snoop Transactions:  
RO  
1b  
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  
150  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.53  
VC1RCTL—VC1 Resource Control (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
120–123h  
01000000h  
RO, R/W  
32 bits  
Size:  
This register controls the resources associated with PCI Express Virtual Channel 1.  
Bit  
Access &  
Default  
Description  
31  
R/W  
0b  
VC1 Enable: 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.  
0 = Virtual Channel is disabled.  
1 = Virtual Channel is enabled. See exceptions in following notes.  
NOTES:  
1.  
2.  
3.  
4.  
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.  
BIOS Requirement: This field must not be set to 1b.  
30:27  
26:24  
Reserved  
R/W  
VC1 ID: This field assigns a VC ID to the VC resource. The assigned value must  
001b  
be non-zero. This field cannot be modified when the VC is already enabled.  
23:8  
7:1  
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. 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.  
0
RO  
0b  
TC0/VC1 Map: Traffic Class 0 is always routed to VC0.  
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151  
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5.1.54  
VC1RSTS—VC1 Resource Status (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
126–127h  
0002h  
RO  
Size:  
16 bits  
This register reports the Virtual Channel specific status.  
Bit  
Access &  
Default  
Description  
15:2  
1
Reserved  
RO  
1 b  
VC1 Negotiation Pending: 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.  
0 = The VC negotiation is complete.  
1 = The VC resource is still in the process of negotiation (initialization or  
disabling).  
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  
5.1.55  
RCLDECH—Root Complex Link Declaration Enhanced  
Capability Header (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
140–143h  
00010005h  
RO  
Size:  
32 bits  
This capability declares links from this element (PCI Express) to other elements of the root  
complex component to which it belongs. See the PCI Express specification for link/topology  
declaration requirements.  
Bit  
Access &  
Default  
Description  
31:20  
19:16  
15:0  
RO  
000h  
Pointer to Next Capability: This is the last capability in the PCI Express*  
extended capabilities list.  
RO  
1h  
Link Declaration Capability Version: Hardwired to 1 to indicate compliances  
with PCI Express Specification, Revision 1.0a.  
RO  
Extended Capability ID: The value of 0005h identifies this linked list item  
0005h  
(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.  
152  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.56  
ESD—Element Self Description (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
144–147h  
02000100h  
RO, R/WO  
32 bits  
Size:  
This register provides information about the root complex element containing this Link  
Declaration Capability.  
Bit  
Access &  
Default  
Description  
31:24  
RO  
02h  
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.  
23:16  
15:8  
R/WO  
00h  
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.  
RO  
01h  
Number of Link Entries: This field identifies the number of link entries following  
the Element Self Description. This field reports 1 (to Egress port only as no peer-  
to-peer capabilities are reported in this topology).  
7:4  
3:0  
Reserved  
RO  
0h  
Element Type: This field identifies the type of the Root Complex Element.  
Value of 0h represents a root port.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
153  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.57  
LE1D—Link Entry 1 Description (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
150–153h  
00000000h  
RO, R/WO  
32 bits  
Size:  
This register contains the first part of a Link Entry, which declares an internal link to another  
Root Complex Element.  
Bit  
Access &  
Default  
Description  
31:24  
RO  
00h  
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.  
23:16  
R/WO  
00h  
Target Component ID: This field identifies the physical or logical component that  
is targeted by this link entry.  
15:2  
1
Reserved  
RO  
0b  
Link Type: This bit identifies that the link points to memory-mapped space (for  
RCRB). The link address specifies the 64-bit base address of the target RCRB.  
0
R/WO  
0b  
Link Valid:  
0 = Link Entry is not valid and will be ignored.  
1 = Link Entry specifies a valid link.  
5.1.58  
LE1A—Link Entry 1 Address (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
158158–15Fh  
0000000000000000h  
R/WO  
Size:  
64 bits  
This register contains the second part of a Link Entry that declares an internal link to another Root  
Complex element.  
Bit  
Access &  
Default  
Description  
63:32  
31:12  
Reserved  
R/WO  
Link Address: This field contains the memory-mapped base address of the  
0 0000h  
RCRB that is the target element (Egress Port) for this link entry.  
11:0  
Reserved  
154  
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Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.59  
UESTS—Uncorrectable Error Status (D1:F0)  
Bus/Dev/Func/Type:  
Address Offset:  
Default Value:  
Access:  
0/1/0/MMR  
1C4–1C7h  
00000000h  
RO, R/WC/S  
32 bits  
Size:  
This register reports error status of individual error sources on a PCI Express device. An  
individual error status bit that is set indicates that a particular error occurred.  
Note: Software clears an error status by writing a 1 to the respective bit.  
Bit  
Access  
& Default  
Description  
31:2  
1
Reserved  
20  
R/WC/S  
0b  
Unsupported Request Error Status:  
0 = Error did Not occur  
1 = Error occurred  
19  
18  
Reserved  
R/WC/S  
0b  
Malformed TLP Status:  
0 = Error did Not occur  
1 = Error occurred  
17  
16  
R/WC/S  
0b  
Receiver Overflow Status:  
0 = Error did Not occur  
1 = Error occurred  
R/WC/S  
0b  
Unexpected Completion Status:  
0 = Error did Not occur  
1 = Error occurred  
15  
14  
Reserved  
R/WC/S  
0b  
Completion Timeout Status:  
0 = Error did Not occur  
1 = Error occurred  
13:5  
4
Reserved  
R/WC/S  
0b  
Data Link Protocol Error Status (DLPES): The Data Link Layer Protocol Error that  
causes this bit to be set will also cause the Fatal Error Detected bit (bit 2) in the  
DSTS (Device Status, D1:F0) to be set if not already set.  
0 = Error did Not occur  
1 = Error occurred  
3:0  
Reserved  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
155  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.60  
UEMSK—Uncorrectable Error Mask (D1:F0)  
Bus/Dev/Func/Type:  
Address Offset:  
Default Value:  
Access:  
0/1/0/MMR  
1C8–1CBh  
00000000h  
RO, R/W/S  
32 bits  
Size:  
This register controls reporting of individual errors by the device (or logic associated with this  
port) to the PCI Express Root Complex. As these errors are not originating on the other side of a  
PCI Express link, no PCI Express error message is sent, but the unmasked error is reported  
directly to the root control logic. A masked error (respective bit set to 1 in the mask register) has  
no action taken. There is a mask bit per error bit of the Uncorrectable Error Status register.  
Bit  
Access  
& Default  
Description  
31:21  
20  
Reserved  
R/W/S  
0b  
Unsupported Request Error Mask:  
0 = Not masked  
1 = Masked  
19  
18  
Reserved  
R/W/S  
0b  
Malformed TLP Mask:  
0 = Not masked  
1 = Masked  
17  
16  
R/W/S  
0b  
Receiver Overflow Mask:  
0 = Not masked  
1 = Masked  
R/W/S  
0b  
Unexpected Completion Mask:  
0 = Not masked  
1 = Masked  
15  
14  
Reserved  
R/W/S  
0b  
Completion Timeout Mask:  
0 = Not masked  
1 = Masked  
13:5  
4
Reserved  
R/W/S  
0b  
Data Link Protocol Error Mask  
0 = Not masked  
1 = Masked  
3:0  
Reserved  
156  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.61  
CESTS—Correctable Error Status (D1:F0)  
Bus/Dev/Func/Type:  
Address Offset:  
Default Value:  
Access:  
0/1/0/MMR  
1D0–1D3h  
00000000h  
RO,R/WC/S  
32 bits  
Size:  
This register reports error status of individual error sources on a PCI Express device. An  
individual error status bit that is set indicates that a particular error occurred.  
Note: Software clears an error status by writing a 1 to the respective bit.  
Bit  
Access  
& Default  
Description  
31:1  
3
Reserved  
12  
R/WC/S  
0b  
Replay Timer Timeout Status:  
0 = Error did Not occur  
1 = Error occurred  
11:9  
8
Reserved  
R/WC/S  
0b  
Replay Number Rollover Status:  
0 = Error did Not occur  
1 = Error occurred  
7
6
R/WC/S  
0b  
Bad DLLP Status:  
0 = Error did Not occur  
1 = Error occurred  
R/WC/S  
0b  
Bad TLP Status:  
0 = Error did Not occur  
1 = Error occurred  
5:1  
0
Reserved  
R/WC/S  
0b  
Receiver Error Status (RES): Receiver errors will be indicated due to all of the  
following: 8b/10b Decode Errors, Framing Errors, Lane Deskew Errors, and Elasticity  
Buffer Overflow/Underflow.  
0 = Error did Not occur  
1 = Error occurred  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
157  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.62  
CEMSK—Correctable Error Mask (D1:F0)  
Bus/Dev/Func/Type:  
Address Offset:  
Default Value:  
Access:  
0/1/0/MMR  
1D4–1D7h  
00000000h  
RO, R/W/S  
32 bits  
Size:  
This register controls reporting of individual correctable errors by the device (or logic associated  
with this port) to the PCI Express Root Complex. As these errors are not originating on the other  
side of a PCI Express link, no PCI Express error message is sent; however, the unmasked error is  
reported directly to the root control logic. A masked error (respective bit set to 1 in the mask  
register) has no action taken. There is a mask bit per error bit of the Correctable Error Status  
register.  
Bit  
Access &  
Default  
Description  
31:13  
12  
Reserved  
R/W/S  
0b  
Replay Timer Timeout Mask:  
0 = Not masked  
1 = Masked  
11:9  
8
Reserved  
R/W/S  
0b  
Replay Number Rollover Mask:  
0 = Not masked  
1 = Masked  
7
6
R/W/S  
0b  
Bad DLLP Mask:  
0 = Not masked  
1 = Masked  
R/W/S  
0b  
Bad TLP Mask:  
0 = Not masked  
1 = Masked  
5:1  
0
Reserved  
R/W/S  
0b  
Receiver Error Mask:  
0 = Not masked  
1 = Masked  
158  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
5.1.63  
PEG_SSTS—PCI Express* Sequence Status (D1:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
1
218–21Fh  
0000000000000FFFh  
RO  
Size:  
64 bits  
This register provides PCI Express status reporting that is required by the PCI Express  
specification.  
Bit  
Access &  
Default  
Description  
63:60  
59:48  
Reserved  
RO  
000h  
Next Transmit Sequence Number: This field contains the 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.  
47:44  
43:32  
Reserved  
RO  
000h  
Next Packet Sequence Number: This field contains the packet sequence  
number to be applied to the next TLP to be transmitted or re-transmitted onto the  
Link.  
31:28  
27:16  
Reserved  
RO  
Next Receive Sequence Number: This field contains the sequence number  
000h  
associated with the TLP that is expected to be received next.  
15:12  
11:0  
Reserved  
RO  
Last Acknowledged Sequence Number: This field contains the sequence  
FFFh  
number associated with the last acknowledged TLP.  
§
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
159  
Host-PCI Express* Bridge Registers (D1:F0) (Intel® 82945G/82945GC/82945P/82945PL Only)  
160  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Direct Media Interface (DMI) RCRB  
6 Direct Media Interface (DMI) RCRB  
This Root Complex Register Block (RCRB) controls the (G)MCH-ICH7 serial interconnect. The  
base address of this space is programmed in DMIBAR in D0:F0 configuration space. Table 6-1  
provides an address map of the DMI registers listed by address offset in ascending order.  
Section 6.1 provides a detailed bit description of the registers.  
Note: All RCRB register spaces need to remain organized as they are here.  
Table 6-1. DMI Register Address Map  
Offset  
Address  
Register  
Symbol  
Register Name  
PCI Dev #  
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  
DMIVCECH  
DMIPVCCAP1  
DMIPVCCAP2  
DMIPVCCTL  
DMI Virtual Channel Enhanced Capability Header  
DMI Port VC Capability Register 1  
DMI Port VC Capability Register 2  
DMI Port VC Control  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
Reserved  
DMIVC0RCAP  
DMIVC0RCTL  
DMI VC0 Resource Capability  
DMI VC0 Resource Control  
Reserved  
DMIVC0RSTS  
DMIVC1RCAP  
DMIVC1RCTL  
DMI VC0 Resource Status  
DMI VC1 Resource Capability  
DMI VC1 Resource Control  
Reserved  
DMIVC1RSTS  
DMI VC1 Resource Status  
Reserved  
084–087h  
088–089h  
08A–08Bh  
1C4–1C7h  
DMILCAP  
DMILCTL  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMIBAR  
DMI Link Capabilities  
DMI Link Control  
DMILSTS  
DMI Link Status  
DMIUESTS  
DMIUEMSK  
DMI Uncorrectable Error Status  
DMI Uncorrectable Error Mask  
1C8–  
1CBh  
1D0–1D3h  
08C–1FFh  
DMICESTS  
DMIBAR  
DMIBAR  
DMI Correctable Error Status  
Reserved  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
161  
Direct Media Interface (DMI) RCRB  
6.1  
DMI RCRB Configuration Register Details  
6.1.1  
DMIVCECH—DMI Virtual Channel Enhanced Capability  
Header  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
000–003h  
04010002h  
RO  
Size:  
32 bits  
This register indicates DMI Virtual Channel capabilities.  
Bit  
Access &  
Default  
Description  
31:20  
19:16  
15:0  
RO  
040h  
Pointer to Next Capability: This field indicates the next item in the list.  
RO  
1h  
Capability Version: This field indicates support as a version 1 capability  
structure.  
RO  
Capability ID: This field indicates this is the Virtual Channel capability item.  
0002h  
6.1.2  
DMIPVCCAP1—DMI Port VC Capability Register 1  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
004–007h  
00000001h  
RO, R/WO  
32 bits  
Size:  
This register describes the configuration of Virtual Channels associated with this port.  
Bit  
Access &  
Default  
Description  
31:12  
11:10  
Reserved  
RO  
Port Arbitration Table Entry Size (PATS): This field indicates the size of the  
00b  
port arbitration table is 4 bits (to allow up to 8 ports).  
9:8  
RO  
Reference Clock (RC): This field is hardwired for a clock of 10 ns.  
00b  
7
Reserved  
6:4  
RO  
Low Priority Extended VC Count (LPEVC): This field indicates that there are  
000b  
no additional VCs of low priority with extended capabilities.  
3
Reserved  
2:0  
R/WO  
001b  
Extended VC Count: This field indicates that there is one additional VC (VC1)  
that exists with extended capabilities.  
162  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Direct Media Interface (DMI) RCRB  
6.1.3  
DMIPVCCAP2—DMI Port VC Capability Register 2  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
008–00Bh  
00000001h  
RO  
Size:  
32 bits  
This register describes the configuration of Virtual Channels associated with this port.  
Bit  
Access &  
Default  
Description  
31:24  
RO  
VC Arbitration Table Offset (ATO): This field indicates that no table is present  
00h  
for VC arbitration since it is fixed.  
23:8  
7:0  
Reserved  
RO  
VC Arbitration Capability: This field indicates that the VC arbitration is fixed in  
01h  
the root complex. VC1 is highest priority and VC0 is lowest priority.  
6.1.4  
DMIPVCCTL—DMI Port VC Control  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
00C–00Dh  
0000h  
RO, R/W  
16 bits  
Size:  
Bit  
Access &  
Default  
Description  
15:4  
3:1  
Reserved  
R/W  
000b  
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.  
0
Reserved  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
163  
Direct Media Interface (DMI) RCRB  
6.1.5  
DMIVC0RCAP—DMI VC0 Resource Capability  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
010–013h  
00000001h  
RO  
Size:  
32 bits  
Bit  
Access &  
Default  
Description  
31:23  
22:16  
Reserved  
RO  
Maximum Time Slots (MTS): This VC implements fixed arbitration; therefore, this  
00h  
field is not used.  
15  
RO  
0b  
Reject Snoop Transactions (RTS): This VC must be able to take snoopable  
transactions.  
14:8  
7:0  
Reserved  
RO  
Port Arbitration Capability (PAC): This field indicates that this VC uses fixed  
01h  
port arbitration.  
164  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Direct Media Interface (DMI) RCRB  
6.1.6  
DMIVC0RCTL—DMI VC0 Resource Control  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
014–017h  
800000FEh  
RO, R/W  
32 bits  
Size:  
This register controls the resources associated with PCI Express Virtual Channel 0.  
Bit  
Access &  
Default  
Description  
31  
RO  
1b  
Virtual Channel Enable (EN):  
0 = Disable  
1 = Enable.  
30:27  
26:24  
Reserved  
RO  
Virtual Channel Identifier (ID): This field indicates the ID to use for this virtual  
000b  
channel.  
23:20  
19:17  
Reserved  
R/W  
0h  
Port Arbitration Select (PAS): This field 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.  
16:8  
7:1  
Reserved  
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. For example when bit 7 is set  
in this field, Transaction Class 7 is mapped to this Virtual channel resource. When  
more than one bit in this field is set, it indicates that multiple Transaction Classes  
from the Transcation Class/Virtual Channel map of an enabled Virtual Channel,  
software must ensure that no new or outstanding transactions with the  
Transaction Class labels are targeted at the given Link.  
0
Reserved  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
165  
Direct Media Interface (DMI) RCRB  
6.1.7  
DMIVC0RSTS—DMI VC0 Resource Status  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
01A–01Bh  
0002h  
RO  
Size:  
16 bits  
This register reports the Virtual Channel specific status.  
Bit  
Access &  
Default  
Description  
15:2  
1
Reserved  
VC Negotiation Pending (NP):  
RO  
1 b  
0 = The Virtual Channel negotiation is complete.  
1 =The Virtual Channel resource is still in the process of negotiation (initialization  
or disabling).  
NOTE: 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  
6.1.8  
DMIVC1RCAP—DMI VC1 Resource Capability  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
01C–01Fh  
00008001h  
RO  
Size:  
32 bits  
Bit  
Access &  
Default  
Description  
31:16  
15  
Reserved  
Reject Snoop Transactions (RTS):  
RO  
1b  
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.  
14:8  
7:0  
Reserved  
RO  
Port Arbitration Capability (PAC): This field indicates the port arbitration  
01h  
capability is time-based WRR of 128 phases.  
166  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Direct Media Interface (DMI) RCRB  
6.1.9  
DMIVC1RCTL—DMI VC1 Resource Control  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
020–023h  
01000000h  
R/W  
Size:  
32 bits  
This register controls the resources associated with Virtual Channel 1.  
Bit  
Access &  
Default  
Description  
31  
R/W  
0b  
Virtual Channel 1 Enable (VC1E):  
0 = Disable  
1 = Enable  
30:27  
26:24  
Reserved  
R/W  
001b  
Virtual Channel 1 Identifier (VC1ID): This field indicates the ID to use for this  
virtual channel. Assigned value must be non-zero. This field can not be modified  
when the VC is already enabled.  
23:20  
19:17  
Reserved  
R/W  
0h  
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.  
16:8  
7:1  
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.  
0
Reserved  
6.1.10  
DMIVC1RSTS—DMI VC1 Resource Status  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
026–027h  
0002h  
RO  
Size:  
16 bits  
This register reports the Virtual Channel specific status.  
Bit  
Access &  
Default  
Description  
15:2  
1
Reserved  
RO  
0b  
VC Negotiation Pending (NP):  
0 = VC negotiation Not pending  
1 = Virtual channel is still being negotiated with ingress ports.  
0
Reserved  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
167  
Direct Media Interface (DMI) RCRB  
6.1.11  
DMILCAP—DMI Link Capabilities  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
084–087h  
00012C41h  
RO, R/WO  
32 bits  
Size:  
This register indicates DMI specific capabilities.  
Bit  
Access &  
Default  
Description  
31:18  
17:15  
Reserved  
R/WO  
010b  
L1 Exit Latency (EL1): L1 is not supported on DMI.  
14:12  
11:10  
9:4  
R/WO  
010b  
L0s Exit Latency (EL0): This field indicates that exit latency is 128 ns to less than  
256 ns.  
RO  
11b  
Active State Link PM Support (APMS): This field indicates that L0s is supported  
on DMI.  
RO  
4h  
Maximum Link Width (MLW): This field indicates the maximum link width is  
4 ports.  
3:0  
RO  
1h  
Maximum Link Speed (MLS): This field indicates the link speed is 2.5 Gb/s.  
6.1.12  
DMILCTL—DMI Link Control  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
088–089h  
0000h  
R/W  
Size:  
16 bits  
This register allows control of DMI.  
Bit  
Access &  
Default  
Description  
15:8  
7
Reserved  
Extended Synch (ES):  
R/W  
0 h  
1 = Forces extended transmission of FTS ordered sets when exiting L0s prior to  
entering L0.  
6:2  
1:0  
Reserved  
R/W  
00 b  
Active State Link PM Control (APMC): This field indicates whether DMI should  
enter L0s.  
00 = Disabled  
01 = L0s entry enabled  
10 = Reserved  
11 = Reserved  
168  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Direct Media Interface (DMI) RCRB  
6.1.13  
DMILSTS—DMI Link Status  
MMIO Range:  
Address Offset:  
Default Value:  
Access:  
DMIBAR  
08A–08Bh  
0001h  
RO  
Size:  
16 bits  
This register indicates DMI status.  
Bit  
Access &  
Default  
Description  
15:10  
9:4  
Reserved  
RO  
Negotiated Link Width (NLW): The negotiated link width is x4 (000100b).  
00h  
3:0  
RO  
1h  
Link Speed (LS): Link is 2.5 Gb/s.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
169  
Direct Media Interface (DMI) RCRB  
6.1.14  
DMIUESTS—DMI Uncorrectable Error Status  
Bus/Dev/Func/Type:  
Address Offset:  
Default Value:  
Access:  
0/0/0/DMIBAR  
1C4–1C7h  
00000000h  
R/WC/S  
Size:  
32 bits  
This register reports error status of individual uncorrectable error sources on DMI. An individual  
error status bit that is set indicates that a particular error occurred.  
Note: Software clears an error status by writing a 1 to the respective bit.  
Bit  
Access  
& Default  
Description  
31:21  
20  
Reserved  
R/WC/S  
0b  
Unsupported Request Error Status:  
0 = Error did Not occur  
1 = Error occurred  
19  
18  
Reserved  
R/WC/S  
0b  
Malformed TLP Status:  
0 = Error did Not occur  
1 = Error occurred  
17  
16  
R/WC/S  
0b  
Receiver Overflow Status:  
0 = Error did Not occur  
1 = Error occurred  
R/WC/S  
0b  
Unexpected Completion Status:  
0 = Error did Not occur  
1 = Error occurred  
15  
14  
Reserved  
R/WC/S  
0b  
Completion Timeout Status:  
0 = Error did Not occur  
1 = Error occurred  
13:5  
4
Reserved  
R/WC/S  
0b  
Data Link Protocol Error Status:  
0 = Error did Not occur  
1 = Error occurred  
3:0  
Reserved  
170  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Direct Media Interface (DMI) RCRB  
6.1.15  
DMIUEMSK—DMI Uncorrectable Error Mask  
Bus/Dev/Func/Type:  
Address Offset:  
Default Value:  
Access:  
0/0/0/DMIBAR  
1C8–1CBh  
00000000h  
R/W/S  
Size:  
32 bits  
This register controls reporting of individual uncorrectable errors over DMI. A masked error  
(respective bit set to 1 in the mask register) has no action taken. There is a mask bit per error bit  
of the DMIUESTS register.  
Bit  
Access  
& Default  
Description  
31:21  
20  
Reserved  
R/W/S  
0b  
Unsupported Request Error Mask:  
0 = Not masked  
1 = Masked  
19  
18  
Reserved  
R/W/S  
0b  
Malformed TLP Mask:  
0 = Not masked  
1 = Masked  
17  
16  
R/W/S  
0b  
Receiver Overflow Mask:  
0 = Not masked  
1 = Masked  
R/W/S  
0b  
Unexpected Completion Mask:  
0 = Not masked  
1 = Masked  
15  
14  
Reserved  
R/W/S  
0b  
Completion Timeout Mask:  
0 = Not masked  
1 = Masked  
13:5  
4
Reserved  
R/W/S  
0b  
Data Link Protocol Error Mask:  
0 = Not masked  
1 = Masked  
3:0  
Reserved  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
171  
Direct Media Interface (DMI) RCRB  
6.1.16  
DMICESTS—DMI Correctable Error Status  
Bus/Dev/Func/Type:  
Address Offset:  
Default Value:  
Access:  
0/0/0/DMIBAR  
1D0–1D3h  
00000000h  
R/WC/S  
Size:  
32 bits  
This register reports error status of individual correctable error sources on DMI. An individual  
error status bit that is set indicates that a particular error occurred.  
Note: Software clears an error status by writing a 1 to the respective bit.  
Bit  
Access  
& Default  
Description  
31:13  
12  
Reserved  
R/WC/S  
0b  
Replay Timer Timeout Status:  
0 = Error did Not occur  
1 = Error occurred  
11:9  
8
Reserved  
R/WC/S  
0b  
REPLAY_NUM Rollover Status:  
0 = Error did Not occur  
1 = Error occurred  
7
6
R/WC/S  
0b  
Bad DLLP Status:  
0 = Error did Not occur  
1 = Error occurred  
R/WC/S  
0b  
Bad TLP Status:  
0 = Error did Not occur  
1 = Error occurred  
5:1  
0
Reserved  
R/WC/S  
0b  
Receiver Error Status (RES): Receiver errors will be indicated due to all of the  
following: 8b/10b Decode Errors, Framing Errors, Lane Deskew Errors, and  
Elasticity Buffer Overflow/Underflow.  
0 = Error did Not occur  
1 = Error occurred  
§
172  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7 Integrated Graphics Device  
(D2:F0) (Intel® 82945G/82945GC/  
82945GZ GMCH Only)  
The Integrated Graphics Device registers are located in Device 2 (D2), Function 0 (F0) and  
Function 1 (F1). This chapter provides the descriptions for the D2:F0 registers. Table 7-1  
provides an address map of the D2:F0 registers listed in ascending order by address offset.  
Section 7.1 provides a detailed bit description of the registers.  
Function 0 can be VGA compatible or not; this is selected through bit 1 of the GGC register  
(D0:F0, offset 52h).  
Note: The following sections describe Device 2 PCI configuration registers only.  
Table 7-1. Integrated Graphics Device Register Address Map (D2:F0)  
Address  
Offset  
Symbol  
Register Name  
Default  
Value  
Access  
00–01h  
02–03h  
04–05h  
06–07h  
08h  
VID2  
DID2  
Vendor Identification  
8086h  
2772h  
0000h  
0090h  
RO  
RO  
Device Identification  
PCI Command  
PCICMD2  
PCISTS2  
RID2  
RO, R/W  
RO  
PCI Status  
Revision Identification  
See register  
description  
RO  
09–0Bh  
0Ch  
CC  
CLS  
Class Code  
030000h  
00h  
RO  
RO  
Cache Line Size  
0Dh  
MLT2  
HDR2  
Master Latency Timer  
Header Type  
00h  
RO  
0Eh  
80h  
RO  
0Fh  
Reserved  
10–13h  
14–17h  
18–1Bh  
MMADR  
IOBAR  
GMADR  
Memory Mapped Range Address  
I/O Base Address  
00000000h  
00000001h  
00000008h  
RO, R/W  
RO, R/W  
Graphics Memory Range Address  
RO,  
R/W/L  
1C–1Fh  
GTTADR  
Graphics Translation Table Range  
Address  
00000000h  
RO, R/W  
20–2Bh  
2C–2Dh  
2E–2Fh  
Reserved  
SVID2  
SID2  
Subsystem Vendor Identification  
Subsystem Identification  
0000h  
0000h  
R/WO  
R/WO  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
173  
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
Address  
Offset  
Symbol  
Register Name  
Default  
Value  
Access  
30–33h  
34h  
ROMADR  
CAPPOINT  
Video BIOS ROM Base Address  
Capabilities Pointer  
Reserved  
00000000h  
90h  
RO  
RO  
35–3Bh  
3Ch  
INTRLINE  
INTRPIN  
MINGNT  
MAXLAT  
Interrupt Line  
01h  
01h  
00h  
00h  
R/W  
RO  
RO  
RO  
3Dh  
Interrupt Pin  
3Eh  
Minimum Grant  
3Fh  
Maximum Latency  
Reserved  
40–43h  
44h  
MCAPPTR  
Mirror of Device 0 Capability Pointer  
Reserved  
E0h  
RO  
45–47h  
48–50h  
MCAPID  
Mirror of Device 0 Capability  
Identification  
0000000000  
01090009h  
RO  
51h  
Reserved  
52–53h  
MGGC  
Mirror of Device 0 GMCH Graphics  
Control  
0030h  
RO  
54–57h  
MDEVEN  
Mirror of Device 0 Device Enable  
See register  
description  
RO  
58–5Bh  
5C–5Fh  
60–61h  
63–CFh  
D0–D1h  
D2–D3h  
D4–D5h  
D6–D7h  
E0–E1h  
E2–E3h  
E4–E7h  
E8h–FBh  
FC–FFh  
BSM  
Reserved  
07800000h  
0000h  
RO  
Base of Stolen Memory  
Reserved  
R/W  
Reserved  
PMCAPID  
PMCAP  
PMCS  
Power Management Capabilities ID  
Power Management Capabilities  
Power Management Control/Status  
Reserved  
0001h  
0022h  
0000h  
RO  
RO  
RO, R/W  
SWSMI  
Software SMI  
0000h  
R/W  
Reserved  
ASLE  
System Display Event  
Reserved  
00000000h  
R/W  
ASLS  
ASL Storage  
00000000h  
R/W  
174  
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Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1  
Configuration Register Details (D2:F0)  
7.1.1  
VID2—Vendor Identification (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
00h  
8086h  
RO  
Size:  
16 bits  
This register, combined with the Device Identification register, uniquely identifies any PCI  
device.  
Bit  
Access &  
Default  
Description  
15:0  
RO  
Vendor Identification Number (VID): This field provides the PCI standard  
8086h  
identification for Intel.  
7.1.2  
DID2—Device Identification (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
02h  
2772h  
RO  
Size:  
16 bits  
This register, combined with the Vendor Identification register, uniquely identifies any PCI  
device.  
Bit  
Access &  
Default  
Description  
15:0  
RO  
Device Identification Number (DID): This is a 16 bit value assigned to the GMCH  
2772h  
Graphic device  
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175  
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.3  
PCICMD2—PCI Command (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
04h  
0000h  
RO, R/W  
16 bits  
Size:  
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  
Description  
15:11  
10  
Reserved  
R/W  
0b  
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  
Fast Back-to-Back (FB2B): Hardwired to 0. Not Implemented.  
RO  
0b  
SERR Enable (SERRE): Hardwired to 0. Not Implemented.  
RO  
0b  
Address/Data Stepping Enable (ADSTEP): Hardwired to 0. Not Implemented.  
RO  
0b  
Parity Error Enable (PERRE): Hardwired to 0. Not Implemented. 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.  
5
4
3
2
RO  
0b  
Video Palette Snooping (VPS): This bit is hardwired to 0 to disable snooping.  
RO  
0b  
Memory Write and Invalidate Enable (MWIE): Hardwired to 0. The IGD does  
not support memory write and invalidate commands.  
RO  
0b  
Special Cycle Enable (SCE): Hardwired to 0. The IGD ignores special cycles.  
R/W  
0b  
Bus Master Enable (BME):  
0 = Disable IGD bus mastering.  
1 = Enable the IGD to function as a PCI compliant master.  
1
0
R/W  
0b  
Memory Access Enable (MAE): This bit controls the IGD’s response to memory  
space accesses.  
0 = Disable.  
1 = Enable.  
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  
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Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.4  
PCISTS2—PCI Status (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
06h  
0090h  
RO  
Size:  
16 bits  
PCISTS2 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  
15  
14  
13  
12  
11  
10:9  
8
Access &  
Default  
Description  
RO  
0b  
Detected Parity Error (DPE): Hardwired to 0. The IGD does not detect parity.  
Signaled System Error (SSE): Hardwired to 0. The IGD never asserts SERR#.  
RO  
0b  
RO  
0b  
Received Master Abort Status (RMAS): Hardwired to 0. The IGD never gets a  
Master Abort.  
RO  
0b  
Received Target Abort Status (RTAS): Hardwired to 0. The IGD never gets a  
Target Abort.  
RO  
0b  
Signaled Target Abort Status (STAS): Hardwired to 0. The IGD does not use  
target abort semantics.  
RO  
00b  
DEVSEL Timing (DEVT): N/A. Hardwired to 00b.  
RO  
0b  
Master Data Parity Error Detected (DPD): Hardwired to 0. Parity Error  
Response is hardwired to disabled (and the IGD does not do any parity  
detection).  
7
6
5
4
RO  
1b  
Fast Back-to-Back (FB2B): Hardwired to 1. The IGD accepts fast back-to-back  
when the transactions are not to the same agent.  
RO  
0b  
User Defined Format (UDF): Hardwired to 0.  
RO  
0b  
66 MHz PCI Capable (66C): N/A. Hardwired to 0.  
RO  
1b  
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.  
3
RO  
0b  
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.  
2:0  
Reserved  
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Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.5  
RID2—Revision Identification (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
08h  
See bit description  
RO  
Size:  
8 bits  
This register contains the revision number for Device 2, Functions 0 and 1.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Revision Identification Number (RID): This is an 8-bit value that indicates the  
revision identification number for the GMCH. Refer to the Intel®  
945G/945GC/945GZ/945P/945PL Express Chipset Specification Update for the  
value of the Revision ID register.  
7.1.6  
CC—Class Code (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
09h  
030000h  
RO  
Size:  
24 bits  
This register contains the device programming interface information related to the Sub-Class  
Code and Base Class Code definition for the IGD. This register also contains the Base Class Code  
and the function sub-class in relation to the Base Class Code.  
Bit  
Access &  
Default  
Description  
23:16  
RO  
Base Class Code (BCC): This is an 8-bit value that indicates the base class  
03h  
code for the GMCH.  
03h = Display Controller.  
15:8  
7:0  
RO  
00h  
Sub-Class Code (SUBCC): The value in this field is determined based on  
Device 0 GGC register, bit 1.  
00h = VGA compatible  
80h = Non VGA  
RO  
00h  
Programming Interface (PI):  
00h = Display controller.  
178  
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Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.7  
7.1.8  
7.1.9  
CLS—Cache Line Size (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
0Ch  
00h  
RO  
8 bits  
Size:  
The IGD does not support this register as a PCI slave.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
00h  
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.  
MLT2—Master Latency Timer (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
0Dh  
00h  
RO  
8 bits  
Size:  
The IGD does not support the programmability of the master latency timer because it does not  
perform bursts.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Master Latency Timer Count Value: Hardwired to 0s.  
00h  
HDR2—Header Type (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
0Eh  
80h  
RO  
8 bits  
Size:  
This register contains the Header Type of the IGD.  
Bit  
Access &  
Default  
Description  
7
RO  
1b  
Multi Function Status (MFunc): This bit indicates if the device is a multi-  
function 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.  
6:0  
RO  
00h  
Header Code (H): This field 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.  
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Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.10  
MMADR—Memory Mapped Range Address (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
10h  
00000000h  
RO, R/W  
32 bits  
Size:  
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  
31:19  
18:4  
3
Access &  
Default  
Description  
R/W  
0000h  
Memory Base Address: Set by the operating system, these bits correspond to  
address signals 31:19.  
RO  
0000h  
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.  
RO  
0b  
2:1  
0
RO  
00b  
RO  
0b  
180  
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Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.11  
IOBAR—I/O Base Address (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
14h  
00000001h  
RO, R/W  
32 bits  
Size:  
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 zero; bit 0 is hardwired to a one indicating that 8 bytes of I/O space are  
decoded.  
Access to the 8 Bytes of I/O space is allowed in PM state D0 when the I/O Enable bit  
(PCICMD[0]) is set to 1. Access is disallowed in PM states D1–D3 or if the I/O 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 is 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 fall within the 8 Bytes claimed.  
Bit  
Access &  
Default  
Description  
31:16  
15:3  
Reserved  
R/W  
IO Base Address: Set by the operating system, these bits correspond to  
0000h  
address signals 15:3.  
2:1  
0
RO  
00b  
Memory Type: Hardwired to 0s to indicate 32-bit address.  
RO  
1b  
Memory / IO Space: Hardwired to 1 to indicate I/O space.  
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Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.12  
GMADR—Graphics Memory Range Address (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
18h  
00000008h  
RO, R/W/L  
32 bits  
Size:  
The IGD graphics memory base address is specified in this register.  
Bit  
31:28  
27:4  
3
Access &  
Default  
Description  
R/W  
0h  
Memory Base Address: Set by the OS, these bits correspond to address signals  
31:28.  
RO  
000000h  
Address Mask: Hardwired to 0s to indicate a 256-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.  
RO  
1b  
2:1  
0
RO  
00b  
RO  
0b  
7.1.13  
GTTADR—Graphics Translation Table Range Address  
(D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
1Ch  
00000000h  
RO, R/W/L  
32 bits  
Size:  
This register requests allocation for the Graphics Translation Table Range. The allocation is for  
256 KB and the base address is defined by bits 31:18.  
Bit  
31:18  
17:4  
3
Access &  
Default  
Description  
R/W  
0000h  
Memory Base Address (MBA): Set by the operating system, these bits  
correspond to address signals 31:18.  
RO  
0000h  
Address Mask (ADMSK): Hardwired to 0s to indicate a 256 KB address range.  
Prefetchable Memory (PREFMEM): Hardwired to 0 to prevent prefetching.  
Memory Type (MEMTYP): Hardwired to 0s to indicate 32-bit address.  
Memory/IO Space (MIOS): Hardwired to 0 to indicate memory space.  
RO  
0b  
2:1  
0
RO  
00b  
RO  
0b  
182  
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Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.14  
SVID2—Subsystem Vendor Identification (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
2Ch  
0000h  
R/WO  
16 bits  
Size:  
Bit  
Access &  
Default  
Description  
15:0  
R/WO  
0000h  
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.  
7.1.15  
SID2—Subsystem Identification (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
2Eh  
0000h  
R/WO  
16 bits  
Size:  
Bit  
Access &  
Default  
Description  
15:0  
R/WO  
0000h  
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.  
7.1.16  
ROMADR—Video BIOS ROM Base Address (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
30h  
00000000h  
RO  
Size:  
32 bits  
The IGD does not use a separate BIOS ROM; therefore, this register is hardwired to 0s.  
Bit  
Access &  
Default  
Description  
31:18  
17:11  
RO  
0000h  
ROM Base Address: Hardwired to 0s.  
RO  
Address Mask: Hardwired to 0s to indicate 256-KB address range.  
00h  
10:1  
0
Reserved  
RO  
0b  
ROM BIOS Enable: Hardwired to 0 to indicate ROM is not accessible.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
183  
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.17  
CAPPOINT—Capabilities Pointer (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
34h  
90h  
RO  
8 bits  
Size:  
Bit  
Access &  
Default  
Description  
7:0  
RO  
90h  
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 MSI  
Capabilities ID registers at address 90h, or the Power Management Capabilities  
ID registers at address D0h.  
7.1.18  
INTRLINE—Interrupt Line (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
3Ch  
01h  
R/W  
8 bits  
Size:  
Bit  
Access &  
Default  
Description  
7:0  
R/W  
01h  
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 is connected to the device’s interrupt  
pin.  
7.1.19  
INTRPIN—Interrupt Pin (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
3Dh  
01h  
RO  
8 bits  
Size:  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Interrupt Pin: As a device that only has interrupts associated with a single  
01h  
function, the IGD specifies INTA# as its interrupt pin.  
01h = INTA#.  
184  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.20  
MINGNT—Minimum Grant (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
3Eh  
00h  
RO  
8 bits  
Size:  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Minimum Grant Value: The IGD does not burst as a PCI compliant master.  
00h  
7.1.21  
MAXLAT—Maximum Latency (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
3Fh  
00h  
RO  
8 bits  
Size:  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Maximum Latency Value: The IGD has no specific requirements for how often it  
00h  
needs to access the PCI bus.  
7.1.22  
7.1.23  
MCAPPTR—Mirror of Device 0 Capability Pointer (D2:F0)  
(Mirrored_D0_34)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
44h  
E0h  
RO  
8 bits  
Size:  
This register is a read only copy of Device 0, offset 34h register.  
MCAPID—Mirror of Device 0 Capability Identification  
(D2:F0) (Mirrored_D0_E0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
48h  
000000000001090009h  
RO  
Size:  
72 bits  
This register is a read only copy of Device 0, offset E0h register.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
185  
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.24  
7.1.25  
MGGC—Mirror of Device 0 GMCH Graphics Control (D2:F0)  
(Mirrored_D0_52)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
52h  
0030h  
RO  
Size:  
16 bits  
This register is a read only copy of Device 0, offset 52h register.  
MDEVEN—Mirror of Device 0 Device Enable (D2:F0)  
(Mirrored_D0_54)  
PCI Device:  
2
Address Offset:  
Default Value:  
54h  
82945G/82945GC/82945GZ GMCH: 0000001Bh  
82945P/82945PL MCH: 00000003h  
Access:  
Size:  
RO  
32 bits  
This register is a read only copy of Device 0, Function 0, offset 54h register.  
7.1.26  
BSM—Base of “Stolen” Memory (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
5Ch  
07800000h  
RO  
Size:  
32 bits  
Graphics Stolen Memory and TSEG are within DRAM space defined under TOLUD. From the  
top of low used DRAM, the GMCH claims 1 to 64 MBs of DRAM for internal graphics if  
enabled.  
Bit  
Access &  
Default  
Description  
31:20  
RO  
078h  
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.  
19:0  
Reserved  
186  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.27  
PMCAPID—Power Management Capabilities ID (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
D0h  
0001h  
RO  
Size:  
16 bits  
Bit  
15:8  
7:0  
Access &  
Description  
Default  
RO  
00h  
NEXT_PTR: This field contains a pointer to the next item in the capabilities list.  
This is the final capability in the list and must be set to 00h.  
RO  
CAP_ID: SIG defines this ID is 01h for power management.  
01h  
7.1.28  
PMCAP—Power Management Capabilities (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
D2h  
0022h  
RO  
Size:  
16 bits  
Bit  
Access &  
Default  
Description  
15:11  
RO  
00h  
PME Support: This field indicates the power states in which the IGD may assert  
PME#. The field is hardwired to 0s to indicate that the IGD does not assert the  
PME# signal.  
10  
9
RO  
0b  
D2: Hardwired to 0 to indicate that the D2 power management state is not  
supported.  
RO  
0b  
D1: Hardwired to 0 to indicate that the D1 power management state is not  
supported.  
8:6  
5
Reserved  
RO  
1b  
Device Specific Initialization (DSI): Hardwired to 1 to indicate that special  
initialization of the IGD is required before generic class device driver is to use it.  
4
3
RO  
0b  
Auxiliary Power Source: Hardwired to 0.  
RO  
0b  
PME Clock: Hardwired to 0 to indicate IGD does not support PME# generation.  
2:0  
RO  
010b  
Version: Hardwired to 010b to indicate that there are 4 bytes of power  
management registers implemented and that this device complies with the PCI  
Power Management Interface Specification, Revision 1.1.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
187  
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.29  
PMCS—Power Management Control/Status (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
D4h  
0000h  
RO, R/W  
16 bits  
Size:  
Bit  
Access &  
Default  
Description  
15  
RO  
0b  
PME_Status: This bit is 0 to indicate that the IGD does not support PME#  
generation from D3 (cold).  
14:9  
8
Reserved  
RO  
0b  
PME_En: This bit is 0 to indicate that PME# assertion from D3 (cold) is disabled.  
7:2  
1:0  
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  
7.1.30  
SWSMI—Software SMI (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
E0h  
0000h  
R/W  
16 bits  
Size:  
As long as there is the potential that DVO port legacy drivers exist that expect this register at this  
address, D2, F0, address E0h–E1h must be reserved for this register.  
Bit  
Access &  
Default  
Description  
15:8  
7:1  
0
R/W  
00h  
SW scratch bits  
R/W  
00h  
Software Flag: This field indicates the caller and SMI function desired, as well  
as return result.  
R/W  
0b  
GMCH Software SMI Event: Software must write a 0 to clear this bit.  
0 = SMI Not triggered.  
1 = When set, this bit will trigger an SMI.  
188  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
7.1.31  
ASLE—System Display Event Register (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
E4h  
00000000h  
R/W  
Size:  
32 bits  
Byte, Word, or Double Word PCI configuration cycles can access this register.  
Bit  
Access &  
Default  
Description  
31:24  
R/W  
00h  
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 16-  
bit or 32-bit write, only one interrupt is generated in common.  
23:16  
15:8  
7:0  
R/W  
00h  
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 16-  
bit or 32-bit write, only one interrupt is generated in common.  
R/W  
00h  
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 16-  
bit or 32-bit write, only one interrupt is generated in common.  
R/W  
00h  
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 16-  
bit or 32-bit write, only one interrupt is generated in common.  
7.1.32  
ASLS—ASL Storage (D2:F0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
FCh  
00000000h  
R/W  
Size:  
32 bits  
This software scratch register is 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  
Description  
31:0  
R/W  
RW according to a software controlled usage to support device switching.  
00000000h  
§
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
189  
Integrated Graphics Device (D2:F0) (Intel® 82945G/82945GC/ 82945GZ GMCH Only)  
190  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
8 Integrated Graphics Device  
(D2:F1) Registers (Intel®  
82945G/82945GC/82945GZ GMCH  
Only)  
The Integrated Graphics Device registers are located in Device 0 (D0), Function 0 (F0) and  
Function 1 (F1). This chapter provides the descriptions for the D2:F1 registers. Table 8-1  
provides an address map of the D2:F1registers listed in ascending order by address offset.  
Detailed bit descriptions follow this table.  
Table 8-1. Device 2 Function 1 Register Address Map (D2:F1)  
Address  
Offset  
Symbol  
Register Name  
Default  
Value  
Access  
00–01h  
02–03h  
04–05h  
06–07h  
08h  
VID2  
DID2  
Vendor Identification  
8086h  
2776h  
0000h  
0090h  
RO  
RO  
Device Identification  
PCI Command  
PCICMD2  
PCISTS2  
RID2  
RO, R/W  
RO  
PCI Status  
Revision Identification  
See register  
description  
RO  
09–0Bh  
0Ch  
CC  
CLS  
Class Code Register  
Cache Line Size  
03800h  
00h  
RO  
RO  
0Dh  
MLT2  
HDR2  
Master Latency Timer  
Header Type Register  
Reserved  
00h  
RO  
0Eh  
80h  
RO  
0Fh  
10–13h  
14–2Bh  
2C–2Dh  
2E–2Fh  
30–33h  
34h  
MMADR  
Memory Mapped Range Address  
Reserved  
00000000h  
RO, R/W  
SVID2  
SID2  
Subsystem Vendor Identification  
Subsystem Identification  
Video BIOS ROM Base Address  
Capabilities Pointer  
Reserved  
0000h  
0000h  
00000000h  
D0h  
R/WO  
R/WO  
RO  
ROMADR  
CAPPOINT  
RO  
35–3Dh  
3Eh  
MINGNT  
MAXLAT  
Minimum Grant Register  
Maximum Latency  
00h  
RO  
3Fh  
00h  
RO  
40–43h  
Reserved  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
191  
Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
Address  
Offset  
Symbol  
Register Name  
Default  
Value  
Access  
44h  
MCAPPTR  
Mirror of Device 0 Capability Pointer  
Reserved  
E0h  
RO  
45–47h  
48–50h  
MCAPID  
Mirror of Device 0 Capability Identification  
0000000000  
01090009h  
RO  
51h  
Reserved  
52–53h  
MGGC  
Mirror of Device 0 GMCH Graphics  
Control  
0030h  
RO  
54–57h  
58–5Bh  
5C–5Fh  
60–CFh  
D0–D1h  
D2–D3h  
D4–D5h  
D6–DFh  
E0–E1h  
E2–FBh  
FC–FFh  
MDEVEN  
Mirror of Device 0 Device Enable  
Reserved  
0000001Bh  
RO  
BSM  
Base of Stolen Memory Register  
Reserved  
07800000h  
0000h  
0001h  
0022h  
0000h  
RO  
PMCAPID  
PMCAP  
PMCS  
Power Management Capabilities ID  
Power Management Capabilities  
Power Management Control/Status  
Reserved  
RO  
RO  
RO, R/W  
SWSMI  
Software SMI  
0000h  
R/W  
Reserved  
ASLS  
ASL Storage  
00000000h  
R/W  
8.1.1  
8.1.2  
VID2—Vendor Identification (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
00h  
8086h  
RO  
Size:  
16 bits  
This register is a copy of Device2, Function 0. It has the same read, write attributes as Function 0.  
It is implemented as common hardware with two access addresses.  
DID2—Device Identification (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
02h  
2776h  
RO  
Size:  
16 bits  
This register is unique in Function 1 (the 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.  
192  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
8.1.3  
PCICMD2—PCI Command (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
04h  
0000h  
RO, R/W  
16 bits  
Size:  
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  
Description  
15:10  
9
Reserved  
RO  
0b  
Fast Back-to-Back (FB2B): Hardwired to 0. Not Implemented.  
8
7
6
RO  
0b  
SERR Enable (SERRE): Hardwired to 0. Not Implemented.  
RO  
0b  
Address/Data Stepping Enable (ADSTEP): Hardwired to 0. Not Implemented.  
RO  
0b  
Parity Error Enable (PERRE): Hardwired to 0. Not Implemented. 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.  
5
4
3
2
RO  
0b  
VGA Palette Snoop Enable (VGASNOOP): Hardwired to 0 to disable snooping.  
RO  
0b  
Memory Write and Invalidate Enable (MWIE): Hardwired to 0. The IGD does  
not support memory write and invalidate commands.  
RO  
0b  
Special Cycle Enable (SCE): Hardwired to 0. The IGD ignores special cycles.  
R/W  
0b  
Bus Master Enable (BME):  
0 = Disable.  
1 = Enable. Enable the IGD to function as a PCI compliant master.  
1
0
R/W  
0b  
Memory Access Enable (MAE): This bit controls the IGD’s response to memory  
space accesses.  
0 = Disable.  
1 = Enable.  
R/W  
0b  
I/O Access Enable (IOAE): This bit controls the IGD’s response to I/O space  
accesses.  
0 = Disable.  
1 = Enable.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
193  
Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
8.1.4  
PCISTS2—PCI Status (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
06h  
0090h  
RO  
Size:  
16 bits  
PCISTS2 reports the occurrence of a PCI compliant master abort and PCI compliant target abort.  
PCISTS2 also indicates the DEVSEL# timing that has been set by the IGD.  
Bit  
15  
14  
13  
12  
11  
10:9  
8
Access &  
Default  
Description  
RO  
0b  
Detected Parity Error (DPE): Hardwired to 0. The IGD does not detect parity.  
Signaled System Error (SSE): Hardwired to 0. The IGD never asserts SERR#.  
RO  
0b  
RO  
0b  
Received Master Abort Status (RMAS): Hardwired to 0. The IGD never gets a  
master abort.  
RO  
0b  
Received Target Abort Status (RTAS): Hardwired to 0. The IGD never gets a  
target abort.  
RO  
0b  
Signaled Target Abort Status (STAS): Hardwired to 0. The IGD does not use  
target abort semantics.  
RO  
00b  
DEVSEL Timing (DEVT): N/A. Hardwired to 00.  
RO  
0b  
Master Data Parity Error Detected (DPD): Hardwired to 0. Since Parity Error  
Response is hardwired to disabled (and the IGD does not do any parity  
detection), this bit is hardwired to 0.  
7
6
5
4
RO  
1b  
Fast Back-to-Back (FB2B): Hardwired to 1. The IGD accepts fast back-to-back  
when the transactions are not to the same agent.  
RO  
0b  
User Defined Format (UDF): Hardwired to 0.  
66 MHz PCI Capable (66C): Hardwired to 0.  
RO  
0b  
RO  
1b  
Capability List (CLIST): This bit is hardwired to 1 to indicate that the register at  
34h provides an offset into the function’s PCI configuration space containing a  
pointer to the location of the first item in the list.  
3
RO  
0b  
Interrupt Status: Hardwired to 0.  
2:0  
Reserved  
194  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
8.1.5  
RID2—Revision Identification (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
08h  
See bit description  
RO  
Size:  
8 bits  
This register is a copy of Device 2, Function 0. It has the same read, write attributes as Function  
0. It is implemented as common hardware with two access addresses.  
Bit  
Access &  
Default  
Description  
7:0  
RO  
Revision Identification Number (RID): This is an 8-bit value that indicates the  
revision identification number for the GMCH. Refer to the Intel®  
945G/945GC/945GZ/945P/945PL Express Chipset Specification Update for the  
value of the Revision ID register.  
8.1.6  
CC—Class Code Register (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
09h  
038000h  
RO  
Size:  
24 bits  
This register contains the device programming interface information related to the Sub-Class  
Code and Base Class Code definition for the IGD. This register also contains the Base Class Code  
and the function sub-class in relation to the Base Class Code.  
Bit  
Access &  
Default  
Description  
23:16  
RO  
Base Class Code (BCC): This is an 8-bit value that indicates the base class  
03h  
code for the GMCH.  
03h = Display controller.  
Sub-Class Code (SUBCC):  
80h = Non VGA  
15:8  
7:0  
RO  
80h  
RO  
00h  
Programming Interface (PI):  
00h = Display controller.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
195  
Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
8.1.7  
8.1.8  
8.1.9  
CLS—Cache Line Size (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
0Ch  
00h  
RO  
8 bits  
Size:  
This register is a copy of Device2, Function 0. It has the same read, write attributes as Function 0.  
It is implemented as common hardware with two access addresses.  
MLT2—Master Latency Timer (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
0Dh  
00h  
RO  
8 bits  
Size:  
This register is a copy of Device2, Function 0. It has the same read, write attributes as Function 0.  
It is implemented as common hardware with two access addresses.  
HDR2—Header Type Register (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
0Eh  
80h  
RO  
8 bits  
Size:  
This register is a copy of Device2, Function 0. It has the same read, write attributes as Function 0.  
It is implemented as common hardware with two access addresses.  
196  
Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
8.1.10  
MMADR—Memory Mapped Range Address (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
10h  
00000000h  
RO, R/W  
32 bits  
Size:  
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  
31:19  
18:4  
3
Access &  
Default  
Description  
R/W  
0000h  
Memory Base Address: Set by the operating system, these bits correspond to  
address signals 31:19.  
RO  
0000h  
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.  
RO  
0b  
2:1  
0
RO  
00b  
RO  
0b  
8.1.11  
8.1.12  
SVID2—Subsystem Vendor Identification (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
2Ch  
0000h  
RO  
Size:  
16 bits  
This register is a copy of Device 2, Function 0. It has the same read, write attributes as Function  
0. It is implemented as common hardware with two access addresses.  
SID2—Subsystem Identification (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
2Eh  
0000h  
RO  
Size:  
16 bits  
This register is a read only copy of Device 2, Function 0.  
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Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
8.1.13  
8.1.14  
8.1.15  
8.1.16  
ROMADR—Video BIOS ROM Base Address (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
30h  
00000000h  
RO  
Size:  
32 bits  
This register is a copy of Device 2, Function 0. It has the same read, write attributes as Function  
0. It is implemented as common hardware with two access addresses.  
CAPPOINT—Capabilities Pointer (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
34h  
D0h  
RO  
8 bits  
Size:  
This register is a copy of Device 2, Function 0. It has the same read, write attributes as Function  
0. It is implemented as common hardware with two access addresses.  
MINGNT—Minimum Grant Register (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
3Eh  
00h  
RO  
8 bits  
Size:  
This register is a copy of Device 2, Function 0. It has the same read, write attributes as Function  
0. It is implemented as common hardware with two access addresses.  
MAXLAT—Maximum Latency (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
3Fh  
00h  
RO  
8 bits  
Size:  
This register is a copy of Device 2, Function 0. It has the same read, write attributes as Function  
0. It is implemented as common hardware with two access addresses.  
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Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
8.1.17  
8.1.18  
8.1.19  
8.1.20  
MCAPPTR—Mirror of Device 0 Capability Pointer (D2:F1)  
(Mirrored_D0_34)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
44h  
D0h  
RO  
8 bits  
Size:  
This register is a read only copy of Device 0, Offset 34h register.  
MCAPID—Mirror of Device 0 Capability Identification  
(D2:F1) (Mirrored_D0_E0)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
48h  
000000000001090009h  
RO  
Size:  
72 bits  
This register is a read only copy of Device 0, Offset E0h register.  
MGGC—Mirror of Device 0 GMCH Graphics Control  
(D2:F1) (Mirrored_D0_52)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
52h  
0030h  
RO  
Size:  
16 bits  
This register is a read only copy of Device 0, Offset 52h register.  
MDEVEN—Mirror of Device 0 Device Enable (D2:F1)  
(Mirrored_D0_54)  
PCI Device:  
2
Address Offset:  
Default Value:  
54h  
82945G/82945GC/82945GZ GMCH: 0000001Bh  
82945P/82945PL MCH: 00000003h  
Access:  
Size:  
RO  
32 bits  
This register is a read only copy of Device 0, Function 0, Offset 54h register.  
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8.1.21  
8.1.22  
8.1.23  
BSM—Base of Stolen Memory Register (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
5Ch  
07800000h  
RO  
Size:  
32 bits  
This register is a copy of Device 2, Function 0. It has the same read, write attributes as Function  
0. It is implemented as common hardware with two access addresses.  
PMCAPID—Power Management Capabilities ID (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
D0h  
0001h  
RO  
Size:  
16 bits  
This register is a copy of Device 2, Function 0. It has the same read, write attributes as Function  
0. It is implemented as common hardware with two access addresses.  
PMCAP—Power Management Capabilities (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
D2h  
0022h  
RO  
Size:  
16 bits  
This register is a copy of Device 2, Function 0. It has the same read, write attributes as Function  
0. It is implemented as common hardware with two access addresses.  
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Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
8.1.24  
PMCS—Power Management Control/Status (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
D4h  
0000h  
RO, R/W  
16 bits  
Size:  
Bit  
Access &  
Default  
Description  
15  
RO  
0b  
PME_Status: This bit is 0 to indicate that IGD does not support PME#  
generation from D3 (cold).  
14:9  
8
Reserved  
RO  
0b  
PME_En: This bit is 0 to indicate that PME# assertion from D3 (cold) is disabled.  
7:2  
1:0  
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  
8.1.25  
SWSMI—Software SMI (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
E0h  
0000h  
R/W  
16 bits  
Size:  
This register is a copy of Device 2, Function 0. It has the same read, write attributes as Function  
0. It is implemented as common hardware with two access addresses.  
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8.1.26  
ASLS—ASL Storage (D2:F1)  
PCI Device:  
Address Offset:  
Default Value:  
Access:  
2
FCh  
00000000h  
R/W  
Size:  
32 bits  
This software scratch register is 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/NonVGA), one bit  
for _DGS (enable/disable requested), and two bits for _DCS (enabled now/disabled now,  
connected or not).  
Bit  
Access &  
Default  
Description  
31:0  
R/W  
R/W according to a software controlled usage to support device switching.  
00000000h  
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Integrated Graphics Device (D2:F1) Registers (Intel® 82945G/82945GC/82945GZ GMCH Only)  
8.2  
Device 2 – PCI I/O Registers  
The following are not PCI configuration registers; they are I/O registers.  
8.2.1  
MMIO Index—MMIO Address Register  
I/O Address:  
Default:  
Access:  
Size:  
IOBAR + 0h  
00000000h  
R/W  
32 bits  
A 32 bit I/O write to this port loads the offset of the 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 is used to access  
internal graphics MMIO registers; however, it 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  
31:2  
1:0  
Access &  
Default  
Description  
R/W  
00000000h  
Register Offset: This field selects any one of the DWord registers within the  
MMIO register space of Device 2.  
Reserved  
8.2.2  
MMIO Data—MMIO Data Register  
I/O Address:  
Default:  
Access:  
Size:  
IOBAR + 4h  
00000000h  
R/W  
32 bits  
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, must not be used to access the data port. 8 or 16 bit I/O reads are  
completed normally.  
Bit  
Access &  
Default  
Description  
31:0  
R/W  
MMIO Data Window  
00000000h  
§
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System Address Map  
9 System Address Map  
The 82945G/82945P (G)MCH supports 4 GB of addressable memory space (see Figure 9-1) and  
64 KB+3 bytes of addressable I/O space. The 82945GC/82945GZ/82945PL (G)MCH supports 2  
GB of addressable memory space 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 memory region usage. The 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  
82945G/82945GC/82945GZ GMCH only. The 82945P/82945PL MCH does not have an IGD.  
Note: References to PCI Express applies to the 82945G/82945GC/82945P/82945PL (G)MCH only. The  
82945GZ GMCH does not support PCI Express.  
Note: References to 4 GB addressable memory space applies to the 82945G/82945P only. The  
82945GC/82945GZ/82945PL support 2 GB addressable memory space.  
Addressing of memory ranges larger than 4 GB (2 GB for 82945GC/82945GZ/82945PL) is not  
supported. The HREQ[4:3] FSB pins are decoded to determine whether the access is above or  
below 4 GB (2 GB for 82945GC/82945GZ/82945PL).  
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 (2 GB for 82945GC/82945GZ/82945PL) 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 prevent 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 (82945G/82945GC/82945P/82945PL Only) – Flat memory-mapped address  
space to access device configuration registers. This mechanism can be used to access  
PCI configuration space (0–FFh) and Extended configuration space (100h–FFFh) for  
PCI Express devices. This enhanced configuration access mechanism is defined in the  
PCI Express specification. (64 MB, 128 MB, or 256-MB window)  
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System Address Map  
DMIBAR – This window is used to access registers associated with the (G)MCH/ICH7  
(DMI) register memory range. (4-KB window)  
IFPBAR – Any write to this window will trigger a flush of the (G)MCH’s Global Write  
Buffer to let software include coherency between writes from an isochronous agent and  
writes from the processor (4-KB window).  
GGC – GMCH graphics control register (82945G/82945GC/82945GZ GMCH only).  
This register 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 (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 (82945G/82945GC/82945GZ GMCH only)  
MMADR – IGD registers and internal graphics instruction port (512-KB window)  
IOBAR – I/O access window for 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 that 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 or 512-MB window)  
GTTADR – Internal graphics translation table location (256-KB or 512-KB window).  
Device 2, Function 1 (82945G/82945GC/82945GZ 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 (TOLUD register) are DMI to  
PCI Express VGA range writes. Note that peer-to-peer cycles to the internal graphics VGA  
range are not supported.  
Figure 9-1 shows a simplified form of the the system memory address map.  
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System Address Map  
Figure 9-1. System Address Ranges  
4 GB1  
Device 0  
Bars  
(EPBAR,  
MCHBAR,  
PCIEXBAR,  
DMIBAR)  
Device 1  
Bars  
(MBASE1/  
MLIMIT1,  
PMBASE1/  
PMLIMIT1)  
Device 2  
Bars  
(MMADR,  
GMADR,  
GTTADR)  
PCI Memory  
Address Range  
(Subtractively  
decoded to DMI)  
TOLUD  
Device 0  
GGC  
(Graphics  
Stolen  
Main Memory  
Address Range  
Independently Programmable  
Non-Overlapping Windows  
Memory)  
1 MB  
Legacy Address  
Range  
0
Notes:  
1. The 4 GB maximum is for the 82945G/82945P only. The maximum addressable  
space for the 82945GZ/82945PL is 2 GB.  
MemMap_SysAdr_Ranges  
9.1  
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  
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System Address Map  
Figure 9-2. Microsoft MS-DOS* Legacy Address Range  
000F_FFFFh  
1 MB  
System BIOS (Upper)  
64 KB  
000F_0000h  
000E_FFFFh  
960 KB  
896 KB  
Extended System BIOS  
(Lower)  
000E_0000h  
000D_FFFFh  
64 KB (16 KB x 4)  
Expansion Area  
128 KB (16 KB x 8)  
000C_0000h  
000B_FFFFh  
768 KB  
640 KB  
Legacy Video Area  
(SMM Memory)  
128 KB  
000A_0000h  
0009_FFFFh  
DOS Area  
0000_0000h  
MemMap_Legacy  
9.1.1  
9.1.2  
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.  
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 (Device 2), to PCI Express (Device 1), and/or to the DMI. The appropriate  
mapping depends on which devices are enabled and the programming of the VGA steering bits.  
Based on the VGA steering bits, priority for VGA mapping is constant. 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. Subsequent decoding of regions mapped to PCI Express or the DMI  
depends on the Legacy VGA configuration bits (VGA Enable and MDAP); see the LAC register  
(Device 0, offset 97h). This region is also the default for SMM space.  
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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 previously described. 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 (82945G/82945GC/82945GZ GMCH on ly) 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 configuration bits). 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. This capability is controlled by a VGA  
steering bits and the legacy configuration bit (MDAP bit). 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.  
9.1.3  
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 (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 9-1. Expansion Area Memory Segments  
Memory Segments  
Attributes  
Comments  
0C0000h–0C3FFFh  
0C4000h–0C7FFFh  
0C8000h–0CBFFFh  
0CC000h–0CFFFFh  
0D0000h–0D3FFFh  
0D4000h–0D7FFFh  
0D8000h–0DBFFFh  
0DC000h–0DFFFFh  
W/R  
W/R  
W/R  
W/R  
W/R  
W/R  
W/R  
W/R  
Add-on BIOS  
Add-on BIOS  
Add-on BIOS  
Add-on BIOS  
Add-on BIOS  
Add-on BIOS  
Add-on BIOS  
Add-on BIOS  
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System Address Map  
9.1.4  
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  
memory 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 DRAM.  
Table 9-2. Extended System BIOS Area Memory Segments  
Memory Segments  
Attributes  
Comments  
0E0000h–0E3FFFh  
0E4000h–0E7FFFh  
0E8000h–0EBFFFh  
0EC000h–0EFFFFh  
W/R  
W/R  
W/R  
W/R  
BIOS Extension  
BIOS Extension  
BIOS Extension  
BIOS Extension  
9.1.5  
System BIOS Area (F_0000h–F_FFFFh)  
This area is a single, 64-K 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 manipulating 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 9-3. System BIOS Area Memory Segments  
Memory Segments  
Attributes  
WE RE  
Comments  
0F0000h–0FFFFFh  
BIOS Area  
9.1.6  
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 (writeback)  
or RC (reference clock), it is possible to get IWB cycles targeting DMI. This may occur for DMI  
originated cycles to disabled PAM regions.  
For example, say 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.  
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System Address Map  
9.2  
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 in the TOLUD register). All accesses to addresses  
within this range are forwarded by the (G)MCH to 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 (2 GB for the  
82945GC/82945GZ /82945PL). 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  
(2 GB for the 82945GC/82945GZ/82945PL), there will be physical memory that exists yet is non-  
addressable and therefore unusable by the system.  
The (G)MCH does not limit main memory address space in hardware.  
Figure 9-3. Main Memory Address Range  
4 GB Maximum1  
FFFF_FFFFh  
Flash  
APIC  
Contains Dev 0, 1,  
2 (GMCH Only),  
BARS, and ICH7/  
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  
16 MB  
15 MB  
ISA Hole (optional)  
Main Memory  
0010_000h  
1 MB  
0 MB  
DOS Compatibility  
Memory  
0h  
Notes:  
1. The 4 GB maximum is for the 82945G/82945P Only. The  
maximum memory for the 82945GZ/82945PL is 2 GB .  
MemMap_MainMemory  
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9.2.1  
ISA Hole (15 MB–16 MB)  
A hole can be created at 15 MB–16 MB as controlled by the fixed hole enable bit in the LAC  
register (Device 0, offset 97h). 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.  
Video accelerators originally used this hole. It is also used by validation and customer SV teams  
for test cards. That is why it is being supported. There is no inherent BIOS request for the  
15–16-MB window.  
9.2.2  
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 DRAM for cache  
coherency. When SMM is enabled, the maximum amount of memory available to the system is  
equal to the amount of physical DRAM minus the value in the TSEG register that is fixed at 1  
MB, 2 MB, or 8 MB.  
9.2.3  
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 9-4  
details the location and attributes of the regions. How to enable and disable these ranges are  
described in the (G)MCH Control Register Device 0 (GCC).  
Table 9-4. Pre-Allocated Memory Example for 64-MB DRAM, 1-MB VGA and 1-MB TSEG  
Memory Segments  
Attributes  
Comments  
0000_0000h – 03DF_FFFFh  
03E0_0000h – 03EF_FFFFh  
R/W  
Available system memory 62 MB  
SMM mode only -  
processor reads  
TSEG address range and pre-allocated  
memory  
03F0_0000h – 03FF_FFFFh  
R/W  
Pre-allocated graphics VGA memory.  
1 MB (or 4/8/16/32/64 MB) when IGD is  
enabled.  
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9.3  
PCI Memory Address Range (TOLUD – 4 GB)  
This address range (see Figure 9-4), from the top of physical memory to 4 GB (2 GB for the  
82945GC/82945GZ/82945PL) is normally mapped via the DMI to PCI. Exceptions to this  
mapping include the 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  
(82945G/82945GC/82945GZ GMCH only)  
Addresses decoded to the graphics memory range. (GMADR range)  
Addresses decoded to the Graphics Translation Table range (GTTADR range).  
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 9-4. PCI Memory Address Range  
Intel®  
82945GZ,  
82945PL  
Intel® 82945G,  
82945P  
FFFF_FFFFh  
FFE0_0000h  
4 GB  
2 GB  
High BIOS  
4 GB – 2 MB  
2 GB – 2 MB  
DMI Interface  
(subtractive decode)  
FEF0_0000h  
FEE0_0000h  
4 GB – 17 MB  
4 GB – 18 MB  
2 GB – 17 MB  
2 GB – 18 MB  
FSB Interrupts  
Optional HSEG  
FEDA_0000h to  
FEDB_FFFFh  
DMI Interface  
(subtractive decode)  
FED0_0000h  
4 GB – 19 MB  
2 GB – 19 MB  
Local (processor)  
APIC  
FEC8_0000h  
FEC0_0000h  
I/O APIC  
4 GB – 20 MB  
2 GB – 20 MB  
DMI Interface  
(subtractive decode)  
F000_0000h  
E000_0000h  
4 GB – 256 MB  
2 GB – 256 MB  
PCI Express*  
Configuration Space  
Possible address range  
(Not ensured)  
4 GB – 512 MB  
2 GB – 512 MB  
Programmable windows, graphics  
ranges, PCI Express* Port could be  
here  
DMI Interface  
(subtractive decode)  
TOLUD  
TOLUD  
MemMap_PCI  
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9.3.1  
9.3.2  
APIC Configuration Space (FEC0_0000h–FECF_FFFFh)  
This range is reserved for APIC configuration space. The I/O APIC(s) usually reside in the ICH7  
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.  
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. Non-  
SMM-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 writeback 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 DRAM 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 main memory like an SMM cycle.  
9.3.3  
9.3.4  
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 main memory.  
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 so that full 2 MB must be considered.  
9.3.5  
PCI Express* Configuration Address Space  
The device 0 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. 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.  
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9.3.6  
PCI Express* Graphics Attach (Intel®  
82945G/82945GC/82945P/82945PL GMCH Only)  
The (G)MCH can be programmed to direct memory accesses to the PCI Express interface when  
addresses are within either of two ranges specified via registers in the (G)MCH’s Device 1  
configuration space.  
The first range is controlled via the Memory Base (MBASE) register and Memory Limit  
(MLIMIT) register.  
The second range is controlled via the Prefetchable Memory Base (PMBASE) register and  
Prefetchable Memory Limit (PMLIMIT) register.  
The (G)MCH positively decodes memory accesses to PCI Express memory address space as  
defined by the following inequalities:  
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 the USWC attribute (from the  
processor point of view) to that range. The USWC attribute is used by the processor for write  
combining.  
Note: The (G)MCH Device 1 memory range registers described above are used to allocate memory  
address space for any PCI Express devices 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.  
9.3.7  
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.  
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9.3.8  
Graphics Memory Address Ranges (Intel®  
82945G/82945GC/82945GZ GMCH Only)  
The GMCH can be programmed to direct memory accesses to IGD when addresses are within any  
of three ranges specified via registers in the GMCH’s Device 2 configuration space.  
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 they do not  
steal any physical DRAM memory space.  
GMADR 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.  
9.4  
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. The (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. The TSEG area lies below IGD stolen  
memory.  
The above 1-MB solutions require changes to compatible SMRAM handlers’ code to properly  
execute above 1 MB.  
Note: DMI and PCI Express masters are not allowed to access the SMM space.  
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9.4.1  
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  
Transaction Address Space  
DRAM Space (DRAM)  
Compatible (C)  
High (H)  
000A_0000h to 000B_FFFFh  
FEDA_0000h to FEDB_FFFFh  
000A_0000h to 000B_FFFFh  
000A_0000h to 000B_FFFFh  
TSEG (T)  
(TOLUD-STOLEN-TSEG) to  
TOLUD-STOLEN  
(TOLUD-STOLEN-TSEG) to  
TOLUD-STOLEN  
9.4.2  
SMM Space Restrictions  
If any of the following conditions are not met, 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 DRAM, or to any PCI devices (including DMI, PCI Express, and graphics devices).  
This is a BIOS responsibility.  
Both D_OPEN and D_CLOSE must not be set to 1 at the same time.  
When TSEG SMM space is enabled, the TSEG space must not be reported to the operating  
system as available DRAM. This is a BIOS responsibility.  
Any address translated through the GMADR TLB must not target DRAM from A_0000–  
F_FFFFh.  
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9.4.3  
SMM Space Combinations  
When High SMM is enabled (G_SMRAME=1 and H_SMRAM_EN=1), the compatible SMM  
space is effectively disabled. Processor originated accesses to the compatible SMM space are  
forwarded to PCI Express if VGAEN=1 (also depends on MDAP); otherwise, they are forwarded  
to the DMI. PCI Express and DMI originated accesses are never allowed to access SMM space.  
Table 9-5. SMM Space  
Global Enable  
G_SMRAME  
High Enable  
H_SMRAM_EN  
TSEG Enable  
TSEG_EN  
Compatible  
(C) Range  
High (H)  
Range  
TSEG (T)  
Range  
0
1
1
1
1
X
0
0
1
1
X
0
1
0
1
Disable  
Enable  
Disable  
Disable  
Disable  
Enable  
Enable  
Disable  
Disable  
Enable  
Disable  
Enable  
Enable  
Disabled  
Disabled  
9.4.4  
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 main memory.  
Table 9-6. SMM Control  
G_SMRAME  
D_LCK  
D_CLS  
D_OPEN  
Processor  
in SMM  
Mode  
SMM Code  
Access  
SMM Data  
Access  
0
1
1
1
1
1
1
1
1
X
0
0
0
0
0
1
1
1
X
X
0
0
1
1
X
0
1
X
0
0
1
0
1
X
X
X
X
0
1
X
1
X
0
1
1
Disable  
Disable  
Enable  
Enable  
Enable  
Invalid  
Disable  
Enable  
Enable  
Disable  
Disable  
Enable  
Enable  
Disable  
Invalid  
Disable  
Enable  
Disable  
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9.4.5  
9.4.6  
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 access SMM space.  
Processor WB Transaction to an Enabled SMM Address  
Space  
Processor writeback transactions (HREQ1# = 0) to enabled SMM address space must be written  
to the associated SMM DRAM even though D_OPEN=0 and the transaction is not performed in  
SMM mode. This ensures SMM space cache coherency when cacheable extended SMM space is  
used.  
9.4.7  
SMM Access through GTT TLB (Intel®  
82945G/82945GC/82945GZ 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.  
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, the Invalid Translation Table Entry Flag (ITTEF) in the ERRSTS register is set.  
PCI Express and DMI write accesses through GMADR range 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 GMADR range are not supported; therefore,  
users/systems will have no address translation concerns. PCI Express and DMI reads to GMADR  
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 processor or internal graphics engines. Also,  
since the GMADR snoop would not be directly to the 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 go  
to address 0h.  
9.4.8  
Memory Shadowing  
Any block of memory that can be designated as read only or write only can be “shadowed” into  
(G)MCH DRAM 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.  
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9.4.9  
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: Configuration Address (CONFIG_ADDRESS) register and  
the Configuration Data (CONFIG_DATA) register. These locations are used to implement a  
configuration space access mechanism.  
The processor allows 64 K+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 and,  
therefore, provides addressability for 64 K+3 byte locations. Note that the upper 3 locations can  
be accessed only during I/O address wrap-around when the processor bus HA16# address signal  
is asserted. HA16# is asserted on the processor bus whenever 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.  
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 ICH7 or PCI Express  
are posted. The PCICMD1 register can disable the routing of I/O cycles to PCI Express.  
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.  
For Pentium 4 processors, I/O reads that lie within 8-byte boundaries but cross 4-byte boundaries  
are issued from the processor as 1 transaction. The (G)MCH splits this into 2 separate  
transactions. I/O writes that lie within 8-byte boundaries but cross 4-byte boundaries are assumed  
to be split into 2 transactions by the processor.  
9.4.10  
9.4.11  
PCI Express* I/O Address Mapping  
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. This range is controlled via the I/O Base Address (IOBASE) and I/O Limit Address  
(IOLIMIT) registers in (G)MCH Device 1 configuration space.  
(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_0000 – 000A_FFFF  
MDA = 000B_0000 – 000B_7FFF  
VGAB = 000B_8000 – 000B_FFFF  
MAINMEM = 0100_0000 to TOLUD  
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9.4.12  
Legacy VGA and I/O Range Decode Rules  
The legacy 128-KB VGA memory range 000A_0000h–000B_FFFFh can be mapped to IGD  
(Device 2), to PCI Express (Device 1), and/or to the DMI depending on the programming of the  
VGA steering bits. 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 the  
IGD. The (G)MCH always positively decodes internally mapped devices, namely the IGD and  
PCI Express. Subsequent decoding of regions mapped to PCI Express or the DMI depends on the  
Legacy VGA configurations bits (VGA Enable and MDAP) in the LAC register (Device 0).  
§
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Functional Description  
10 Functional Description  
This chapter describes the (G)MCH interfaces and major functional units.  
10.1  
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 200/267 MHz bus clock, the address signals run at 400/533MT/s. The data is quad  
pumped and an entire 64 B cache line can be transferred in two bus clocks. At 200/267 MHz bus  
clock, the data signals run at 800/1066MT/s for a maximum bandwidth of 10.7 GB/s.  
10.1.1  
10.1.2  
10.1.3  
FSB IOQ Depth  
The Scalable bus supports up to 12 simultaneous outstanding transactions.  
FSB OOQ Depth  
The (G)MCH supports only one outstanding deferred transaction on the FSB.  
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.  
10.1.4  
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]#  
Data Bits  
HDINV0#  
HDINV1#  
HDINV2#  
HDINV3#  
HD15:0#  
HD31:16#  
HD47:32#  
HD63:48#  
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Functional Description  
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.  
10.1.4.1  
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  
10.2  
System Memory Controller  
The system memory controller supports two styles of memory organization (Interleaved and  
Asymmetric). Rules for populating DIMM slots are included in this section. Sample memory  
organizations are provided in Table 10-1 and Table 10-2.  
Note: The 82945G/82945P (G)MCH maximum memory size is 4 GB.  
Note: The 82945GC/82945GZ/82945PL (G)MCH maximum memory size is 2 GB.  
Table 10-1. Sample System Memory Organization with Interleaved Channels  
Rank  
Channel A  
Population  
Cumulative Top  
Address in  
Channel B  
Population  
Cumulative Top  
Address in  
Channel A  
Channel B  
Rank 3  
Rank 2  
Rank 1  
Rank 0  
0 MB  
2560 MB  
2560 MB  
2048 MB  
1024 MB  
0 MB  
2560 MB  
2560 MB  
2048 MB  
1024 MB  
256 MB  
512 MB  
512 MB  
256 MB  
512 MB  
512 MB  
Table 10-2. Sample System Memory Organization with Asymmetric Channels  
Rank  
Channel A  
Population  
Cumulative Top  
address in  
Channel B  
Population  
Cumulative Top  
Address in  
Channel A  
Channel B  
Rank 3  
Rank 2  
Rank 1  
Rank 0  
0 MB  
1280 MB  
1280 MB  
1024 MB  
512 MB  
0 MB  
2560 MB  
2560 MB  
2304 MB  
1792 MB  
256 MB  
512 MB  
512 MB  
256 MB  
512 MB  
512 MB  
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Intel® 82945G/82945GZ/82945GC GMCH and 82945P/82945PL MCH Datasheet  
Functional Description  
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  
ensured 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 10-1 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 10-1 for further clarification.  
Figure 10-1. System Memory Styles  
Dual Channel Interleaved  
(channels must match  
total size)  
Dual Channel Asymmetric  
(channels do not have to  
match)  
Single Channel  
CL  
CL  
CL  
CH B  
TOM  
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  
CH A  
CH A0  
MemSys_Styles  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
225  
Functional Description  
10.2.1  
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 or B. 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 or B. 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 (G)MCH is configured in a dual-channel 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): CLKCFG specifies DRAM frequency. The same clock  
frequency will be driven to all DIMMs.  
DRAM Timing (CxDRT1): The x represents a channel, A or B represented by 0 and 1  
respectively. The DRT Register defines the timing parameters for all devices in a channel.  
BIOS programs this register with “least common denominator” values after reading the SPD  
registers of each DIMM in the channel.  
DRAM Control (CxDRC0): The x represents a channel, A or B represented by 0 and 1  
respectively. DRAM refresh mode, rate, and other controls are selected here.  
10.2.2  
DRAM Technologies and Organization  
"Single sided" below is a logical term referring to the number of chip selects attached to the  
DIMM. A real DIMM may put the components on both sides of the substrate, but be logically  
indistinguishable from single-sided DIMM if all components on the DIMM are attached to the  
same chip select signal.  
x8 means that each component has 8 data lines.  
x16 means that each component has 16 data lines  
All standard 256-Mb, 512-Mb, and 1-Gb technologies and addressing are supported for x16 and  
x8 devices.  
For DDR2:  
400 MHz (PC2 3200)  
Non-ECC  
Version A = Single sided x8  
Version B = Double sided x8  
Version C = Single sided x16  
533 MHz (PC 4300)  
Non-ECC  
Version A = Single sided x8  
Version B = Double sided x8  
Version C = Single sided x16  
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Functional Description  
667 MHz (PC 5300) (82945G/82945GC/82945P (G)MCH Only)  
Non-ECC  
Version C = Single sided x16  
Version D = Single sided x8  
Version E = Double sided x8  
There is No support for DIMMs with different technologies or capacities on opposite sides of the  
same DIMM. If one side of a DIMM is populated, the other side is either identical or empty.  
Supported components include:  
For DDR2 at 533 MHz (PC4300) and 667 MHz (PC5300) (667 MHz on  
82945G/82945GC/82945P (G)MCH Only)  
256-Mb technology  
32-M cells x8 data bits/cell  
1-K columns  
4 banks  
8-K rows  
Each component has a 1-KB page.  
One DIMM has 8 components resulting in an 8-KB page.  
The capacity of one rank is 256 MB.  
16-M cells x16 data bits/cell  
512 columns  
4 banks  
8-K rows  
Each component has a 1-KB page.  
One DIMM has 4 components resulting in a 4-KB page.  
The capacity of one rank is 128 MB.  
512-Mb technology  
64-M cells x8 data bits/cell  
1K columns  
4 banks  
16K rows  
Each component has a 1-KB page.  
One DIMM has 8 components resulting in an 8-KB page.  
The capacity of one rank is 512 MB.  
32-M cells x16 data bits/cell  
1-K columns  
4 banks  
8-K rows  
Each component has a 2-KB page.  
One DIMM has 4 components resulting in an 8-KB page.  
The capacity of one rank is 256 MB.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
227  
Functional Description  
1-Gb technology  
128-M cells x8 data bits/cell  
1-K columns  
8 banks  
16-K rows  
Each component has a 1-KB page.  
One DIMM has 8 components resulting in an 8-KB page.  
The capacity of one rank is 1 GB.  
64-M cells x16 data bits/cell  
1-K columns  
8 banks  
8-K rows  
Each component has a 2-KB page.  
One DIMM has 4 components resulting in an 8-KB page.  
The capacity of one rank is 512MB.  
The DRAM sub-system supports single or dual channels, 64b wide per channel. There can be a  
maximum of 4 ranks populated (2 Double Sided DIMMs) per channel. Mixed mode DDR DS-  
DIMMs (x8 and x16 on the same DIMM) are not supported (not validated)  
By using 1Gb technology, the largest memory capacity is 8 GB (16K rows * 1K columns *  
1 cell/(row * column) * 8 b/cell * 8 banks/device * 8 devices/rank * 4 ranks/channel *  
2 channel *1M/(K*K) * 1G/1024M * 1B/8b = 8 GB). Using 8 GB of memory is only possible in  
Interleaved mode with all ranks populated at maximum capacity. The Intel 82945G GMCH and  
82894P MCH are limited to 4 GB of address space. Any memory in the system beyond 4 GB  
cannot be addressed and should not be populated due to the additional loading it places on the  
memory subsystem.  
By using 256Mb technology, the smallest memory capacity is 128 MB (8K rows * 512 columns *  
1 cell/(row * column) * 16b/cell * 4 banks/device * 4 devices/rank * 1 rank * 1M/1024K * 1B/8b  
= 128 MB)  
10.2.2.1  
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.  
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Functional Description  
10.2.2.2  
System Memory Supported Configurations  
The (G)MCH supports the 256 Mbit, 512 Mbit and 1 Gbit technology based DIMMs from  
Table 10-3.  
Table 10-3. DDR2 DIMM Supported Configurations  
Technology  
Configuration  
# of Row  
Address  
Bits  
# of  
Column  
Address  
Bits  
# of Bank  
Address  
Bits  
Page  
Size  
Rank  
Size  
256Mbit  
256Mbit  
512Mbit  
512Mbit  
1Gbit  
16M X 16  
32M X 8  
32M X 16  
64M X 8  
64M X 16  
128M X 8  
13  
13  
13  
14  
13  
14  
9
2
2
2
2
3
3
4K  
8K  
8K  
8K  
8K  
8K  
128 MB  
256 MB  
256 MB  
512 MB  
512 MB  
1 GB  
10  
10  
10  
10  
10  
1Gbit  
10.2.2.3  
Main Memory DRAM Address Translation and Decoding  
Table 10-4 and Table 10-5 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 10-3. The address lines specified in the column header refer to the host (processor) address  
lines.  
Intel® 82945G/82945G/82945GC GMCH and 82945P/82945PL MCH Datasheet  
229  
S k i z e R a n  
z e  
P a g e S i  
B a n k s  
T e c h  
S k i z e R a n  
z e  
P a g e S i  
B a n k s  
T e c h  
Functional Description  
10.2.3  
10.2.4  
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.  
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.  
10.2.5  
DDR2 On Die Termination  
On die termination (ODT) is a feature that allows a DRAM to turn on/off internal termination  
resistance for each SDQ_x, SDM_x, SDQS_x, and SDQS_x# signal for x8 and x16  
configurations via the SODT_x control signals. The SODT_x feature is designed to improve  
signal integrity of the memory channel by allowing the termination resistance for the SDQ_x,  
SDM_x, SDQS_x, and SDQS_x# signals to be located inside the DRAM devices themselves  
instead of on the motherboard. The (G)MCH drives out the required SODT_x 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.  
232  
Functional Description  
10.3  
PCI Express* (Intel® 82945G/82945GC/  
82945P/82945PL (G)MCH Only)  
Refer to Section 1.3.4 for list of PCI Express features, and the PCI Express specification for  
further details. Refer to Section 10.4 for additional information on the features/capabilities of the  
multiplexed PCI Express interface and SDVO ports.  
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 control registers for this  
functionality are located in device 1 configuration space and two Root Complex Register Blocks  
(RCRBs). The DMI RCRB contains registers for control of the ICH7 attach ports.  
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) that is close to twice the data rate of classic PCI per  
lane.  
10.3.1  
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.  
10.3.2  
10.3.3  
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.  
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.  
233  
Functional Description  
10.4  
Intel® Serial Digital Video Output (SDVO) (Intel®  
82945G/82945GC/82945GZ GMCH Only)  
The 82945G/82945GC GMCH SDVO ports are multiplexed with the PCI Express x16 interface.  
The 82945GZ GMCH SDVO ports are not multiplexed. The Intel® SDVO port is the second  
generation of digital video output from compliant Intel GMCHs. The electrical interface is based  
on the PCI Express interface, though the protocol and timings are completely unique. Whereas  
PCI Express runs at a fixed frequency, the frequency of the SDVO interface is dependant on the  
active display resolution and timing. The port can be dynamically configured in several modes to  
support display configurations.  
Essentially, a SDVO port will transmit display data in a high speed, serial format across  
differential AC coupled signals. A SDVO port consists of a sideband differential clock pair and a  
number of differential data pairs.  
10.4.1  
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 controller 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/ADD2+ card is designed to fit in a x16 PCI Express connector. The ADD2/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 or Dual Simultaneous Standard modes. The ADD2+  
card adds Video in capabilities.  
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.  
234  
Functional Description  
Figure 10-2. SDVO Conceptual Block Diagram  
Analog RGB  
Monitor  
Control Clock  
Control Data  
TV Clock In  
Stall  
Interrupt  
3rd Party  
SDVO  
External  
Device(s)  
Digital  
Display  
Device(s)  
or TV  
ClockC  
Internal  
Graphics  
RedC / AlphaB  
BlueC  
PCI  
Express*  
Logic  
ClockB  
RedB  
GreenB  
BlueB  
GMCH  
SDVO_BlkDia  
Note: PCI Express ports are only on the 82945G/82945GC GMCH. On the 82945GZ,  
these pins are dedicated SDVO pins.  
10.4.2  
Intel® SDVO Modes  
The port can be dynamically configured in several modes:  
Standard. This mode provides baseline SDVO functionality. It supports pixel rates between  
25 MP/s and 200 MP/s. It uses three data pairs to transfer RGB data.  
Extended. This mode adds Alpha support to data stream. It supports pixel rates between  
25 MP/s and 200 MP/s. This 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 MP/s and 200 MP/s.  
Dual Independent Standard. 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.  
235  
Functional Description  
10.4.3  
PCI Express* and Internal Graphics Simultaneous  
Operation (Intel® 82945G/82945GC GMCH Only)  
10.4.3.1  
Standard PCI Express* Cards and Internal Graphics  
BIOS control of simultaneous operation is needed to ensure the PCI Express is configured  
appropriately.  
10.4.3.2  
ADD2+ Cards (Concurrent SDVO and PCI Express*)  
SDVO lane reversal is supported. This functionality allows current SDVO ADD2 cards to work  
in current ATX and BTX systems instead of requiring a separate card. The 82945G GMCH  
allows SDVO and PCI Express to operate concurrently on the PCI Express port. The card that  
plugs into the x16 connector in this case is called an ADD2+ card. It uses 4 or 8 lanes for SDVO  
and up to 8 lanes of standard PCI Express.  
Note: The only supported PCI Express width when SDVO is present is x1.  
Note: The 82945GC supports only ADD2 cards and not ADD2+. The 945GC does not support  
concurrent SDVO and PCI Express*)  
This concurrency is supported in reversed and non-reversed configurations. Mirroring / Reversing  
is always about the axis between PCI Express lanes 7 and 8.  
Table 10-6. Concurrent SDVO / PCI Express* Configuration Strap Controls  
Slot  
Reversed  
Strap  
SDVO  
Present  
Strap  
SDVO/PCI  
Express*  
Concurrent Strap  
Config #  
Description  
1
2
3
4
5
PCI Express not reversed  
PCI Express Reversed  
Yes  
SDVO (ADD2) not reversed  
SDVO (ADD2) Reversed  
Yes  
Yes  
Yes  
Yes  
SDVO and PCI Express (ADD2+)  
not reversed  
Yes  
6
SDVO and PCI Express (ADD2+)  
Reversed  
Yes  
Yes  
Yes  
NOTES:  
1.  
The Configuration #s refer to the following figures (no intentional relation to validation  
configurations).  
2.  
Configurations 4, 5, and 6 are new for the 82945G GMCH (required addition of SDVO/PCI Express  
Concurrent Strap).  
236  
Functional Description  
Figure 10-3. Concurrent SDVO / PCI Express* Non-Reversed Configurations  
GMCH GMCH  
PEG PEG  
Signals Pins  
1
3
5
0
0
0
0
0
0
PCIe Lane 0  
x1  
PCIe  
Card  
x4  
sDVO  
(ADD2)  
PCIe  
Video In  
Card  
PCIe Lane N  
x8  
ADD2+ Card  
x16  
PCIe  
Card  
sDVO  
(ADD2)  
Card  
sDVO Lane  
7
Video Out  
sDVO  
sDVO Lane  
0
15  
15  
15  
15  
15  
SDVO-Conc-PCIe_Non-Reversed_Con  
Figure 10-4. Concurrent SDVO / PCI Express* Reversed Configurations  
GMCH GMCH  
2
4
6
PEG  
PEG  
Signals Pins  
15  
0
15  
15  
15  
sDVO Lane 0  
sDVO  
Video Out  
sDVO Lane 7  
x8  
x16  
PCIe  
Card  
sDVO  
(ADD2)  
Card  
ADD2+ Card  
PCIe Lane N  
PCIe  
x4  
sDVO  
(ADD2)  
Card  
Video In  
x1  
PCIe  
Card  
0
PCIe Lane 0  
0
15  
0
0
0
SDVO-Conc-PCIe_Reversed_Con  
237  
Functional Description  
Figure 10-5. Concurrent SDVO / PCI Express* Signal Multiplexing  
PCIe[15:8]  
PCIe[0:7]  
0
1
0
1
nothing  
0
1
sDVO[0:7]  
0
1
Upper 8 lanes  
nothing  
0
1
sDVO[0:7]  
PCIe[0:7]  
0
1
LaneReversal  
ToPEG  
port pins  
PCIe[7:0]  
0
1
PCIe[8:15]  
0
1
sDVO[7:0]  
0
1
nothing  
Lower 8 lanes  
0
1
nothing  
0
1
PCIe[7:0]  
0
1
sDVO[7:0]  
Gray logic is optional. The sDVO/PCIe  
Concurrent strap is sufficient toindicate  
concurrentconfigurations. It canimply  
that sDVOis present.  
Straps  
Slot Reversed  
sDVO Present  
sDVO/PCIeConcurrent  
SD VO-Conc -PCIe_SignalMux in  
238  
Functional Description  
10.5  
Integrated Graphics Device (Intel®  
82945G/82945GC/82945GZ GMCH Only)  
The major components in the Integrated Graphics Device (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 output of the  
engines are surfaces sent to memory that 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)  
and two digital (SDVO ports B and C). The ports will be explained in more detail later in this  
section .  
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 DDR2 533), the rest of the IGD will also  
be affected.  
The rest of this section will focus on explaining the IGD components, their limitations, and  
dependencies.  
10.5.1  
3D Graphics Pipeline  
The GMCH graphics is the next step in the evolution of integrated graphics. In addition to  
running the graphics engine at 400 MHz, the GMCH graphics has four pixel pipelines that  
provide a 1.3 GB/s fill rate that enables an excellent consumer gaming experience.  
The 3D graphics pipeline for the GMCH has a deep pipelined architecture in which each stage  
can simultaneously operate on different primitives or on different portions of the same primitive.  
The 3D graphics pipeline is divided into four major stages: geometry processing, setup (vertex  
processing), texture application, and rasterization.  
The GMCH graphics is optimized for use with current and future Intel® processors for advance  
software based transform and lighting techniques (geometry processing) as defined by the  
Microsoft Direct X* API. The other three stages of 3D processing are handled on the integrated  
graphics device. The setup stage is responsible for vertex processing; converting vertices to  
pixels. The texture application stage applies textures to pixels. The rasterization engine takes  
textured pixels and applies lighting and other environmental affects to produce the final pixel  
value. From the rasterization stage, the final pixel value is written to the frame buffer in memory  
so it can be displayed.  
239  
Functional Description  
Figure 10-6. Integrated 3D Graphics Pipeline  
Processor  
Geometry:  
Transform and Lighting, Vertex Shader  
GMCH  
Setup Engine:  
Vertices in, Pixels out  
Texture Engine:  
Pixels in, Textured Pixels out  
Raster Engine:  
Textured Pixels in, Final Pixels out  
3D-Gfx_Pipeline  
10.5.2  
3D Engine  
The 3D engine on the 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. The 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 engines’ performance is dependent on the memory bandwidth available. Systems that have  
more bandwidth available will outperform systems with less bandwidth. The engines’  
performance is also dependent on the core clock frequency. The higher the frequency, the more  
data is processed.  
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Functional Description  
10.5.3  
4X Faster 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. For the 82945G/82945GC/82945GZ GMCH, it was  
redesigned to run at 1 cycle/attribute.  
10.5.3.1  
3D Primitives and Data Formats Support  
The 3D primitives rendered by the GMCH are points, lines, discrete triangles, line strips, triangle  
strips, triangle fans, and polygons. In addition to this, the GMCH supports the Microsoft DirectX  
Flexible Vertex Format (FVF) that enables the application to specify a variable length parameter  
list. This obviates 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.  
10.5.3.2  
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, the 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 supports 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”.  
10.5.3.3  
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 assurance of 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.  
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Functional Description  
10.5.3.4  
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 “Backface 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.  
10.5.3.5  
10.5.3.6  
Scan Converter  
Working on a per-polygon basis, the scan converter uses the vertex and edge information to  
identify all pixels affected by features being rendered.  
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.  
10.5.3.7  
Pixel Pipeline  
The pixel pipeline function combines, for each pixel, the interpolated vertex components from the  
scan conversion function, texel values from the texture samplers, and the pixel’s current values  
from the color and/or depth buffers. This combination is performed by a programmable pixel  
shader engine, followed by a pipeline for optional pixel operations performed in a specific order.  
The result of these operations can be written to the color and depth buffers.  
10.5.3.8  
10.5.3.9  
Texture Samplers  
A texture sampler takes a texture coordinate and its partial derivatives, access (samples) texture  
maps, applies filtering and other operations to the texel samples, and feeds the resultant per-pixel  
texel outputs to pixel shader registers. Sixteen texture samplers are supported.  
2D Functionality  
The stretch Block Level Transfer (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.  
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Functional Description  
10.5.4  
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.  
10.5.4.1  
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.  
10.5.4.2  
10.5.4.3  
Texture Formats and Storage  
The GMCH supports up to 32 bits of color for textures.  
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.  
10.5.4.4  
10.5.4.5  
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).  
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.  
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Functional Description  
10.5.4.6  
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.  
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 that  
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 to 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 OGL (Revision 1.1) allow support for all these filtering modes.  
10.5.4.7  
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.  
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Functional Description  
10.5.4.8  
10.5.4.9  
Pixel Shader  
DX9 PS 2.0-compliant pixel shader. This includes perspective-correct diffuse and specular color  
interpolation via internal use of texcoords. In addition, there is support for non-perspective-  
correct texture coordinates as well as support for fog parameter separate from specular alpha.  
Cube Map Textures  
Multiple texture map surfaces arranged into a cubic environment map are supported. There is also  
support for CLAMP and CUBE texture address mode for Cubemaps.  
10.5.4.10 4x4 Texture Filtering Includes Cube Maps  
Compressed Cube Map Mip-amps  
New format support for compressed cube maps that allows each mip/face to exist in its own  
compression block.  
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.  
10.5.5  
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 that determine whether the frame and depth buffers will be updated  
with the new pixel values.  
10.5.5.1  
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.  
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Functional Description  
10.5.5.2  
10.5.5.3  
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 that 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, and BS on a component by component basis.  
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  
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.  
10.5.5.4  
10.5.5.5  
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 components by dithering.  
Dithering is performed on blended textured pixels. In 32-bit mode, dithering is not performed on  
the components.  
Vertex and Per Pixel Fogging  
Fogging is used to create atmospheric effects (such as low visibility conditions in flight simulator-  
type games). It adds another level of realism to computer-generated scenes. Fog can be used for  
depth cueing or hiding distant objects. With fog, distant objects can be rendered with fewer  
details (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. The higher the  
density the lower the 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  
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Functional Description  
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.  
10.5.5.6  
Alpha Blending (Frame Buffer)  
Alpha blending adds the material property of transparency or opacity to an object. Alpha blending  
combines a source pixel color (RS, GS, BS) and alpha (AS) component with a destination pixel  
color (RD, GD, BD) and alpha (AD) component. For example, alpha blending could be used  
where there is glass surface on top (source) of a red surface (destination) allowing 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.  
10.5.5.7  
10.5.5.8  
Microsoft Direct X* API and SGI OpenGL* Logic Ops  
Both APIs provide a mode to use bitwise ops in place of alpha blending. This is used for rubber-  
banding (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.  
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 is 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.).  
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Functional Description  
10.5.5.9  
Depth Buffer  
The raster engine will be able to 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.  
10.5.5.10 Stencil Buffer  
The raster engine will provide 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).  
10.5.5.11 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.  
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Functional Description  
10.5.6  
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.  
10.5.6.1  
10.5.6.2  
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.  
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  
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.  
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Functional Description  
10.5.7  
Video Engine  
10.5.7.1  
Hardware Motion Compensation  
The Motion Compensation (MC) process consists of reconstructing a new picture by predicting  
(either forward, backward, or bidirectionally) 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 supports the following input format:  
YUV420 planar  
4-Channel MPEG YUV  
Improvements allow hardware MC output rate to be quadrupled.  
10.5.7.2  
Sub-Picture Support  
Sub-picture is used for two purposes; one is Subtitles for movie captions, etc. (which are  
superimposed on a main picture), and the other is Menus used to provide some visual operation  
environments for 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. This flexibility enables the GMCH to work with all sub- picture  
formats.  
10.5.8  
Planes  
A plane consists of a 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.  
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Functional Description  
10.5.8.1  
10.5.8.2  
Cursor Plane  
The cursor planes are one of the simplest display planes. With a few exceptions, the cursor plan  
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.  
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.  
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.  
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Functional Description  
10.5.8.3  
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 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 jaggies. In 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 1600X1200 with 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.  
10.5.9  
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.  
10.5.9.1  
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 (DREFCLKN/P) or  
the TV clock input (SDVO_TVCLKIN+/-).  
10.6  
Display Interfaces (Intel® 82945G/82945GC/82945GZ  
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 GMCH has one dedicated display port; the analog port. SDVO ports B and C are multiplexed  
with the PCI Express graphics interface and are not available if an external PCI Express graphics  
252  
Functional Description  
device is in use. When a system uses a PCI Express graphics connector, SDVO ports B and C can  
be used via an ADD2/ADD2+ (Advanced Digital Display 2) card. Ports B and C can also operate  
in dual-channel 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 75 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 @ 60 Hz. When in dual-channel mode,  
the GMCH can drive a flat panel up to 2048x1536 @ 75 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).  
Table 10-7. Display Port Characteristics  
Analog  
Digital Port B  
DVO 1.0  
Digital Port C  
DVO 1.0  
Interface Protocol  
RGB DAC  
HSYNC  
VSYNC  
Yes Enable/Polarity  
Yes Enable/Polarity  
BLANK  
No  
No  
No  
No  
Yes(1)  
Yes  
Yes  
Yes(1)  
Yes  
Yes  
No  
STALL  
Field  
Display_Enable  
Image Aspect Ratio  
Pixel Aspect Ratio  
Voltage  
Programmable and typically 1.33:1 or 1.78:1  
Square(1)  
RGB 0.7 V p-p  
NA  
PCI Express*  
PCI Express  
Clock  
Differential  
Max Rate  
400 Mpixel  
Analog RGB  
DDC1/DDC2B  
No  
200/400 Mpixel  
RGB 8:8:8 YUV 4:4:4  
Format  
Control Bus  
External Device  
Connector  
DDC2B  
TMDS/LVDS Transmitter /TV Encoder  
DVI/CVBS/S-Video/Component/SCART  
VGA/DVI-I  
NOTES:  
1.  
Single signal software selectable between display enable and Blank#.  
10.6.1  
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 satisfactorily but no  
functionality has been added to the signals to enhance that capability.  
253  
Functional Description  
Table 10-8. Analog Port Characteristics  
Signal  
Port Characteristic  
Support  
Voltage Range  
Monitor Sense  
Analog Copy Protection  
Sync on Green  
Voltage  
0.7 V p-p only  
Analog Compare  
RGB  
No  
No  
2.5 V  
Enable/Disable  
Polarity adjust  
Composite Sync Support  
Special Flat Panel Sync  
Stereo Sync  
Port control  
VGA or port control  
HSYNC  
VSYNC  
No  
No  
No  
Voltage  
Externally buffered to 5 V  
Through GPIO interface  
DDC  
Control  
10.6.1.1  
10.6.1.2  
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 @  
75 Hz. Three 8-bit DACs provide the R, G, and B signals to the monitor.  
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 should power up disabled in the high state. No composite sync or special flat  
panel sync support will be included.  
10.6.1.3  
10.6.1.4  
VESA/VGA Mode  
VESA/VGA mode provides compatibility for pre-existing software that sets 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.  
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 plug-  
and-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.  
254  
Functional Description  
10.6.2  
Digital Display Interface  
The GMCH has several options for driving digital displays. The GMCH contains two SDVO  
ports. On the 82945G/82945GC GMCH these ports are multiplexed on the PCI Express interface.  
When an external PCI Express 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 into a PCI Express  
connector.  
10.6.2.1  
Multiplexed Digital Display Channels – Intel® SDVOB and Intel®  
SDVOC  
The 82945G/82945GC/82945GZ GMCH has the capability to support digital display devices  
through two SDVO ports. For the 82945G/82945GC GMCH, when an external graphics  
accelerator is used via the multiplexed PCI Express 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, the GMCH is capable of driving the pixel clock up to  
400 MHz.  
SDVO_CTRLDATA is an open-drain signal that acts 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.  
10.6.2.1.1 ADD2/ADD2+ Card  
When a 945G/945GC Express chipset platform uses a PCI Express connector, the multiplexed  
SDVO ports may be used via an ADD2 card for 945GC and ADD2/ADD2+ card for 945G. The  
ADD2/ADD2+ card will be designed to fit a standard PCI Express (x16) connector.  
10.6.2.1.2 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  
device, but has no native panel fitting capabilities. The GMCH will, however, provide unscaled  
mode where the display is centered on the panel.  
10.6.2.1.3 LVDS Capabilities  
The GMCH may use the SDVO ports to drive an 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.  
255  
Functional Description  
10.6.2.1.4 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. The GMCH supports NTSC/PAL/SECAM 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, the TV-Out port can be configured to be the boot device. It is  
necessary to ensure that appropriate BIOS support is provided.  
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 accomplished using the external encoders PLL combined with the  
display phase detector mechanism. The availability of this feature will be determined by which  
external encoder is in use.  
Analog Content Protection  
Analog content protection will be 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.  
256  
Functional Description  
10.6.2.1.5 Control Bus  
Communication to SDVO registers and if used, 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 GMCH port can be dynamically configured in the Standard, Extended, and Dual Standard  
modes. Refer to Section 10.4.2 for details.  
10.6.3  
Multiple Display Configurations  
Microsoft Windows* 2000 and Windows* XP operating systems have enabled support for multi-  
monitor 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 (see note) supports Intel® Dual Display Clone, Intel  
Dual Display Twin, Intel Dual Display Zoom, and Extended Desktop.  
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.  
Intel Dual Display Zoom uses both display pipes to drive different content, at potentially different  
resolutions, refresh rates, and color depths to two different displays. This configuration results in  
a portion of the primary display to be zoomed in on and displayed on the secondary display.  
Extended desktop 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 82945G/82945GC GMCH IGD is Not capable of operating in parallel with an external PCI  
Express graphics device. The GMCH can, however, work in conjunction with a PCI graphics  
adapter. Intel® Extended Desktop and Dual Display Zoom feature is supported with the 82945G  
GMCH only. Intel® Dual Display Clone and Dual Display Twin are supported with the 82945G,  
82945GC, and the 82945GZ  
257  
Functional Description  
10.7  
Power Management  
Power management feature List:  
ACPI 1.0b support  
ACPI S0, S1D, S3 (both Cold and Chipset Hot), S4, S5, C0, and C1. C2, C3, C4 states and  
corresponding Enhanced states- S3hot, C2, C3, and C4 are not used in the (G)MCH.  
Enhanced power management state transitions for increasing time processor spends in low  
power states  
Internal Graphics Display Device Control D0, D1, D2, D3  
Graphics Adapter States: D0, D3  
PCI Express Link States: L0, L0s (82945G/82945GC/82945P/82945PL Only)  
10.8  
Clocking  
The (G)MCH has a total of 5 PLLs providing many times that many internal clocks. The PLLs  
are:  
Host PLL – This PLL generates the main core clocks in the host clock domain. The Host PLL  
can also be used to generate memory and internal graphics core clocks. It uses the Host clock  
(HCLKIN) as a reference.  
Memory PLL – This PLL can be used to generate memory and internal graphics core clocks,  
when not generated by the Host PLL. The memory PLL is not needed in all configurations,  
but exists to provide more flexible frequency combinations without an unreasonable VCO  
frequency. It uses the Host clock (HCLKIN) as a reference.  
PCI Express PLL – This PLL generates all PCI Express related clocks, including the Direct  
Media Interface that connects to the ICH7. The PCI Express PLL uses the 100 MHz  
(GCLKIN) as a reference.  
Display PLL A (82945G/82945GC/82945GZ GMCH Only) – This PLL generates the  
internal clocks for Display A. It uses DREFCLK as a reference.  
Display PLL B (82945G/82945GC/82945GZ GMCH Only) – This PLL generates the  
internal clocks for Display B. It uses DREFCLK as a reference.  
258  
Functional Description  
Figure 10-7 illustrates the various clocks in the 945G Express chipset platform.  
Figure 10-7. System Clocking Example  
Processor Diff Pair  
CPU_1 /  
CPU_1#  
Processor  
CK410  
56-Pin SSOP  
Processor Diff Pair  
Processor Diff Pair  
CPU_0 /  
CPU_0#  
Memory  
ITP_SRC7 /  
ITP_SRC7 #  
ITP  
FSB  
x16 PCI Express*  
PCI Express  
DIff Pair  
SRC_1 / SRC_1#  
SRC_2 / SRC_2#  
PCI Express GFX  
PCI Express  
DIff Pair  
PCI Express Slot  
(G)MCH  
DMI  
PCI Express DIff Pair  
SRC_3 / SRC_3#  
PCI Express DIff Pair  
SATA Diff Pair  
SRC_5 / SRC_5#  
SRC_4 / SRC_4#  
PCI Express  
LAN  
SRC_6 / SRC_6#  
DOT 96 MHz Diff Pair  
USB 48 MHz  
DOT_96 / DOT_96#  
USB_48 / USB_48#  
REF 14 MHz  
REF 0  
REF 14 MHz  
REF 33 MHz  
SIO LPC  
AC 97  
Intel® ICH7  
REF 14 MHz  
AC 97 Bit Clock  
PCIF_1  
PCI 33 MHz  
LCI Bit Clock  
LAN  
25 MHz Xtal  
PCI 33 MHz  
PCI 33 MHz  
TPM LPC  
OSC  
PCIF_2  
PCI 33 MHz  
FWH LPC  
24 MHz  
Intel® High  
Definition Audio  
PCI 33 MHz  
PCI 33 MHz  
PCI 33 MHz  
32.768 kHz  
PCI_5  
PCI_4  
PCI_3  
PCI_2  
PCI Slot  
PCI Slot  
PCI 33 MHz  
PCI 33 MHz  
PCI 33 MHz  
PCI_1  
PCI_0  
Sys_Clocking  
§
259  
Functional Description  
260  
Electrical Characteristics  
11 Electrical Characteristics  
This chapter contains the (G)MCH absolute maximum electrical ratings, power dissipation values,  
and DC characteristics.  
Note: References to SDVO apply to the 82945G/82945GC/82945GZ GMCH only.  
Note: References to 1066 MHz FSB apply to the 82945G/82945P only.  
Note: References to DDR2-667 apply to the 82945G/82945GC/82945P only.  
Note: References to the PCI Express Interface applies to the 82945G/82945GC/82945P/82945PL only.  
11.1  
Absolute Minimum and Maximum Ratings  
Table 11-1 specifies the (G)MCH’s absolute maximum and minimum ratings. Within functional  
operation limits, functionality and long-term reliability can be expected.  
At conditions outside functional operation condition limits, but within absolute maximum and  
minimum ratings, neither functionality nor long-term reliability can be expected. If a device is  
returned to conditions within functional operation limits after having been subjected to conditions  
outside these limits, but within the absolute maximum and minimum ratings, the device may be  
functional, but with its lifetime degraded depending on exposure to conditions exceeding the  
functional operation condition limits.  
At conditions exceeding absolute maximum and minimum ratings, neither functionality nor long-  
term reliability can be expected. Moreover, if a device is subjected to these conditions for any  
length of time, then, when returned to conditions within the functional operating condition limits,  
it will either not function, or its reliability will be severely degraded.  
Although the (G)MCH contains protective circuitry to resist damage from static electric  
discharge, precautions should always be taken to avoid high static voltages or electric fields.  
261  
Electrical Characteristics  
Table 11-1. Absolute Minimum and Maximum Ratings  
Symbol  
Tstorage  
Parameter  
Storage Temperature  
Min  
Max  
Unit  
Notes  
-55  
150  
C  
1
(G)MCH Core  
VCC  
1.5 V Core Supply Voltage with respect to VSS  
-0.3  
1.65  
V
Host Interface (533 MHz/800 MHz/1066 MHz) (1066 MHz on 82945G/82945P (G)MCH Only)  
VTT  
System Bus Input Voltage with respect to VSS  
-0.3  
-0.3  
1.65  
1.65  
V
V
VCCA_HPLL  
1.5 V Host PLL Analog Supply Voltage with  
respect to VSS  
DDR2 Interface (533 MHz/667 MHz) (667 MHz on 82945G/82945GC/82945P (G)MCH Only)  
VCCSM  
1.8 V DDR2 System Memory Supply Voltage  
with respect to VSS  
-0.3  
-0.3  
4.0  
V
V
VCCA_SMPLL  
1.5 V System Memory PLL Analog Supply  
Voltage with respect to VSS  
1.65  
PCI Express*/SDVO/DMI Interface  
VCC_EXP  
1.5 V PCI Express* and DMI Supply Voltage  
with respect to VSS  
-0.3  
-0.3  
1.65  
1.65  
V
V
VCCA_EXPPLL  
1.5 V PCI Express PLL Analog Supply Voltage  
with respect to VSS  
RGB/CRT DAC Display Interface (8 bit) (82945G/82945GC/82945GZ GMCH Only)  
VCCA_DAC  
2.5 V Display DAC Analog Supply Voltage with  
respect to VSS  
-0.3  
-0.3  
-0.3  
2.65  
1.65  
1.65  
V
V
V
VCCA_DPLLA  
VCCA_DPLLB  
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  
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  
warrant functionality for parts that have exceeded temperatures above 150 °C since this exceeds Intel’s  
specification.  
262  
Electrical Characteristics  
11.1.1  
Power Characteristics  
Table 11-2. Non Memory Power Characteristics  
Symbol  
IVTT  
Parameter  
Signal Names  
Min  
Max  
Unit  
Notes  
System Bus Supply Current  
VTT  
0.9  
13.8  
8.9  
1.5  
70  
A
A
1, 4,5  
IVCC  
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  
VCC  
2,3,4,5  
IVCC  
VCC  
A
2,3,4,5  
IVCC_EXP  
IVCCA_DAC  
IVCC2  
VCC_EXP  
VCCA_DAC  
VCC2  
A
5
5
5
5
mA  
mA  
mA  
2.0  
45  
IVCCA_EXPPLL  
1.5 V PCI Express and DMI PLL Analog  
Supply Current  
VCCA_EXPPLL  
IVCCA_HPLL  
IVCCA_DPLLA  
IVCCA_DPLLB  
1.5 V Host PLL Supply Current  
VCCA_HPLL  
VCCA_DPLLA  
VCCA_DPLLB  
45  
55  
mA  
mA  
5
5
1.5 V Display PLL A and PLL B Supply  
Current (82945G/82945GC/82945GZ  
GMCH Only)  
NOTES:  
1. Estimate is only for maximum current coming through (G)MCH supply balls.  
2. Rail includes DLLs and FSB sense amps.  
3. Includes worst case leakage.  
4. Calculated for highest frequencies.  
5. Icc_max values are determined on a per-interface basis. Maximum currents cannot occur simultaneously on  
all interfaces.  
Table 11-3. DDR2 Power Characteristics  
Symbol  
Parameter  
Min  
Max  
Uni  
t
Notes  
IVCCSM  
ISUS_VCCSM  
ISMVREF  
DDR2 System Memory Interface (1.8 V) Supply Current  
4.0  
25  
2
A
1,2,3  
DDR2 System Memory Interface (1.8 V) Standby Supply Current  
mA  
mA  
1
1
DDR2 System Memory Interface Reference Voltage (0.90 V)  
Supply Current  
ISUS_SMVREF  
DDR2 System Memory Interface Reference Voltage (0.90 V)  
Standby Supply Current  
10  
36  
10  
66  
µA  
mA  
µA  
1
1
1
1
ITTRC  
DDR2 System Memory Interface Resister Compensation  
Voltage (1.8 V) Supply Current  
ISUS_TTRC  
DDR2 System Memory Interface Resister Compensation  
Voltage (1.8 V) Standby Supply Current  
IVCCA_SMPLL  
System Memory PLL Analog (1.5 V) Supply Current  
mA  
NOTES:  
1. Estimate is only for max current coming through (G)MCH supply balls  
2. Calculated for highest frequencies  
3. Icc_max values are determined on a per-interface basis. Maximum currents cannot occur simultaneously on  
all interfaces.  
263  
Electrical Characteristics  
11.2  
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.  
DDR2  
DDR2 System memory (1.8 V CMOS buffers)  
PCI Express/SDVO  
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  
Ref  
Analog signal interface  
Voltage reference signal  
HVCMOS  
SSTL-1.8  
2.5 V Tolerant High Voltage CMOS buffers  
1.8 V Tolerant Stub Series Termination Logic  
Table 11-4. Signal Groups  
Signal  
Group  
Signal Type  
Signals  
Notes  
Host Interface Signal Groups  
(a)  
(b)  
GTL+  
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#  
Input/Outputs  
GTL+  
HBPRI#, HCPURST#, HDEFER#, HTRDY#, HRS[2:0]#,  
HEDRDY#  
Common Clock  
Outputs  
(c)  
(d)  
Asynchronous GTL+  
Input  
HPCREQ#  
Analog Host Interface  
Reference and  
Compensation  
Signals  
HDVREF, HACCVREF, HSWING HRCOMP, HSCOMP  
(c1)  
Miscellaneous CMOS  
Inputs  
BSEL[2:0]  
264  
Electrical Characteristics  
Signal  
Group  
Signal Type  
Signals  
Notes  
PCI-Express* Graphics and Intel® SDVO Interface Signal Groups  
(e)  
PCI Express*/  
PCI Express Interface  
Intel SDVO Input  
(82945G/82945GC/82945P/82945PL Only):  
EXP_RXN[15:0], EXP_RXP[15:0]  
SDVO Interface (82945G/82945GC/82945GZ GMCH Only):  
SDVO_TVCLKIN+, SDVO_TVCLKIN-, SDVOB_INT+,  
SDVOB_INT-, SDVO_STALL+, SDVO_STALL-,  
SDVOC_INT+, SDVOC_INT-  
(f)  
PCI Express/  
SDVO Output  
PCI Express Interface  
(82945G/82945GC/82945P/82945PL Only):  
EXP_TXN[15:0], EXP_TXP[15:0]  
SDVO Interface (82945G/82945GC/82945GZ 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-  
(g)  
Analog  
EXP_COMPO  
EXP_COMPI  
PCI Express/SDVO  
Interface  
Compensation  
Signals  
DDR2 Interface Signal Groups  
(h)  
SSTL – 1.8  
DDR2 CMOS I/O  
SSTL – 1.8  
SDQ_A[63:0], SDQ_B[63:0], SDQS_A[7:0], SDQS_A[7:0]#,  
SDQS_B[7:0], SDQS_B[7:0]#  
(i)  
SDM_A[7:0], SDM_B[7:0], SMA_A[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]#  
DDR2 CMOS Output  
(j)  
DDR2 Reference  
Voltage  
SMVREF[1:0]  
RGB/CRT DAC Display Signal Groups (82945G/82945GC/82945GZ GMCH Only)  
Analog Current  
Outputs  
RED, RED#, GREEN, GREEN#, BLUE, BLUE#  
Analog/Ref DAC  
Miscellaneous  
REFSET  
1
HVCMOS Type  
HSYNC, VSYNC  
Clocks, Reset, and Miscellaneous Signal Groups  
(k) HVCMOS Input EXTTS#  
265  
Electrical Characteristics  
Signal  
Group  
Signal Type  
Signals  
Notes  
(l)  
Miscellaneous Inputs  
RSTIN#, PWROK  
ICH_SYNC#  
Miscellaneous  
HVCMOS Output  
(m)  
(n)  
Low Voltage Diff.  
Clock Input  
HCLKN, HCLKP, DREFCLKP, DREFCLKN, GCLKP,  
GCLKN  
HVCMOS I/O  
(82945G/82945GC  
SDVO_CRTLCLK, SDVO_CTRLDATA, DDC_CLK,  
DDC_DATA  
/8  
2945GZ GMCH Only)  
I/O Buffer Supply Voltages  
(o)  
(p)  
System Bus Input  
Supply Voltage  
VTT  
1.5 V SDVO, PCI  
Express Supply  
Voltages  
VCC_EXP  
(q)  
(r)  
1.8 V DDR2 Supply  
Voltage  
VCCSM  
1.5 V DDR2 PLL  
Analog Supply  
Voltage  
VCC_SMPLL  
(s)  
(t)  
1.5 V (G)MCH Core  
Supply Voltage  
VCC  
2.5 V CMOS Supply  
Voltage  
VCC2  
(u)  
2.5 V RGB/CRT DAC  
Display Analog  
VCCA_DAC  
Supply Voltage  
(v)  
PLL Analog Supply  
Voltages  
VCCA_HPLL, VCCA_EXPPLL, VCCA_DPLLA,  
VCCA_DPLLB  
NOTE:  
1.  
Current Mode Reference pin. DC Specification not required  
266  
Electrical Characteristics  
11.3  
DC Characteristics  
Table 11-5. DC Characteristics  
Symbol  
Signal  
Group  
Parameter  
Min  
Nom  
Max  
Unit  
Notes  
I/O Buffer Supply Voltage (AC Noise not included unless noted)  
VCCSM  
(q)  
(r)  
DDR2 I/O Supply Voltage  
1.7  
1.8  
1.5  
1.9  
V
V
4
VCCA_SMPLL  
DDR2 I/O PLL Analog Supply  
Voltage  
1.425  
1.575  
VCC_EXP  
VTT  
(p)  
(o)  
SDVO, PCI-Express Supply  
Voltage  
1.425  
1.14  
1.5  
1.2  
1.575  
1.26  
V
V
System Bus Input Supply  
Voltage  
VCC  
(s)  
(t)  
GMCH Core Supply Voltage  
CMOS Supply Voltage  
1.425  
2.375  
2.375  
1.5  
2.5  
2.5  
1.575  
2.625  
2.625  
V
V
V
11  
VCC2  
VCCA_DAC  
(u)  
CRT Display DAC Supply  
Voltage  
VCCA_HPLL,  
VCCA_EXPPLL  
,
(v)  
Various PLLs’ Analog Supply  
Voltages  
1.425  
1.5  
1.575  
V
VCCA_DPLLA,  
VCCA_DPLLB  
Reference Voltages  
HVREF  
(d)  
Host Address, Data, and  
Common Clock Signal  
Reference Voltage  
0.63 x VTT –2% 0.63 x VTT  
0.63 x VTT +2%  
V
HSWING  
(d)  
(j)  
Host Compensation Reference 0.22 x VTT –2% 0.22 x VTT  
Voltage  
0.22 x VTT+2%  
0.51 x VCCSM  
V
V
SMVREF  
DDR2 Reference Voltage  
0.49 x VCCSM 0.50 x VCCSM  
Host Interface  
VIL_H  
VIH_H  
(a, c, c1) Host GTL+ Input Low Voltage  
(a, c, c1) Host GTL+ Input High Voltage  
-0.10  
0
(0.63 x VTT) – 0.1  
VTT +0.1  
V
V
(0.63 x  
VTT  
V
TT)+0.1  
VOL_H  
VOH_H  
IOL_H  
(a, b) Host GTL+ Output Low  
Voltage  
(0.22 x VTT)+0.1  
VTT  
V
V
(a, b) Host GTL+ Output High  
Voltage  
VTT – 0.1  
(a, b) Host GTL+ Output Low  
Current  
VTTmax *(1–0.22) / mA Rttmin = 54  
Rttmin  
ILEAK_H  
(a, c, c1) Host GTL+ Input Leakage  
Current  
20  
A  
VOL<Vpad<  
VTT  
267  
Electrical Characteristics  
Symbol  
Signal  
Group  
Parameter  
Min  
Nom  
Max  
Unit  
Notes  
CPAD  
(a, c, c1) Host GTL+ Input Capacitance  
2
2.5  
2.5  
pF  
pF  
CPCKG  
(a, c, c1) Host GTL+ Input Capacitance  
(common clock)  
0.90  
DDR2 Interface  
VIL(DC)  
VIH(DC)  
(h)  
(h)  
DDR2 Input Low Voltage  
DDR2 Input High Voltage  
SMVREF – 0.125  
V
V
SMVREF +  
0.125  
VIL(AC)  
VIH(AC)  
(h)  
(h)  
DDR2 Input Low Voltage  
DDR2 Input High Voltage  
SMVREF – 0.250  
V
V
SMVREF +  
0.250  
VOL  
VOH  
ILeak  
ILeak  
CI/O  
(h, i)  
(h, i)  
(h)  
DDR2 Output Low Voltage  
DDR2 Output High Voltage  
Input Leakage Current  
Input Leakage Current  
1.5  
0.3  
V
1
1
5
6
V
±20  
±550  
6.0  
µA  
µA  
pF  
(h)  
(h, i)  
DDR2 Input/Output Pin  
Capacitance  
3.0  
1.5V PCI Express* Interface 1.0a (includes PCI Express and SDVO)  
VTX-DIFF P-P  
VTX_CM-ACp  
ZTX-DIFF-DC  
VRX-DIFF p-p  
VRX_CM-ACp  
(f)  
(f)  
Differential Peak to Peak  
Output Voltage  
0.800  
1.2  
20  
V
2
AC Peak Common Mode  
Output Voltage  
mV  
(f)  
DC Differential TX Impedance  
80  
100  
120  
1.2  
150  
Ohm  
s
(e)  
(e)  
Differential Peak to Peak Input  
Voltage  
0.175  
V
3
AC Peak Common Mode Input  
Voltage  
mV  
Clocks, Reset, and Miscellaneous Signals  
VIL  
(k)  
(k)  
Input Low Voltage  
0.8  
V
V
VIH  
Input High Voltage  
Input Leakage Current  
Input Capacitance  
2.0  
ILEAK  
(k)  
20  
A  
CIN  
(k)  
3.0  
6.0  
pF  
V
VIL  
(m)  
(m)  
(m)  
(m)  
Input Low Voltage  
- 0.150  
0.660  
0.250  
0
VIH  
Input High Voltage  
Absolute Crossing Point  
Relative Crossing Point  
0.700  
0.850  
0.550  
V
VCROSS(abs)  
VCROSS(rel)  
V
7, 9  
8, 9  
0.250 + 0.5 *  
0.550 + 0.5 *  
V
(VHavg – 0.700)  
(VHavg – 0.770)  
VCROSS  
(m)  
Range of Crossing Points  
0.140  
V
10  
268  
Electrical Characteristics  
Symbol  
Signal  
Group  
Parameter  
Min  
Nom  
Max  
Unit  
Notes  
CIN  
(m)  
(n)  
Input Capacitance  
1
3
pF  
V
VOL  
Output Low Voltage (CMOS  
Outputs)  
0.4  
VOH  
(n)  
(n)  
(n)  
Output High Voltage (CMOS  
Outputs)  
2.1  
-1  
1
V
IOL  
Output Low Current (CMOS  
Outputs)  
mA  
@VOL_HI  
max  
IOH  
Output High Current (CMOS  
Outputs)  
mA @VOH_HI min  
VIL  
(n)  
(n)  
(n)  
(n)  
(l)  
Input Low Voltage  
Input High Voltage  
Input Leakage Current  
Input Capacitance  
Input Low Voltage  
Input High Voltage  
Input Leakage Current  
1.4  
1.1  
V
V
VIH  
ILEAK  
CIN  
VIL  
± 20  
6.0  
A  
3.0  
pF  
V
0.8  
VIH  
(l)  
2.0  
V
ILEAK  
(l)  
±100  
A  
0<Vin<VCC  
3_3  
CIN  
(l)  
Input Capacitance  
4.690  
5.370  
pF  
NOTES:  
1. Determined with 2x GMCH DDR2 Buffer Strength Settings into a 50  
to 0.5xVCCSM test load.  
2. Specified at the measurement point into a timing and voltage compliance test load as shown in Transmitter  
compliance eye diagram of PCI Express specification and measured over any 250 consecutive TX Uls.  
3. Specified at the measurement point and measured over any 250 consecutive Uls. The test load shown in  
Receiver compliance eye diagram of PCI Express specification should be used as the RX device when  
taking measurements.  
4. This is the DC voltage supplied at the (G)MCH and is inclusive of all noise up to 20 MHz. Any noise above  
20 MHz at the (G)MCH generated from any source other than the (G)MCH itself may not exceed the DC  
voltage range of 1.8 V ±100 mV.  
5. Applies to the pin to VCC or VSS leakage current for the SDQ_A[63:0]# and SDQ_B[63:0]# signals.  
6. Applies to the pin-to-pin leakage current between the SDQS_A[7:0], SDQS_A[7:0]#, SDQS_B[7:0]#, and  
SDQS_B[7:0]# signals.  
7. Crossing Voltage is defined as the instantaneous voltage value when the rising edge is equal to the falling  
edge.  
8. VHavg is the statistical average of the VH measured by the oscilloscope.  
9. The crossing point must meet the absolute and relative crossing point specifications simultaneously.  
10. VCROSS is defined as the total variation of all crossing voltages as defined in note 7.  
11. For all noise components 20 MHz, the sum of the DC voltage and AC noise component must be within  
the specified DC min/max operating range.  
269  
Electrical Characteristics  
11.3.1  
RGB/CRT DAC Display DC Characteristics (Intel®  
82945G/82945GC/82945GZ GMCH Only)  
Table 11-6. RGB/CRT DAC Display DC Characteristics: Functional Operating Range  
(VCCA_DAC = 2.5 V 5%)  
Typica  
Parameter  
DAC Resolution  
Min  
Max  
Units  
Notes  
l
8
Bits  
V
1
1, 2, 4 (white video  
level voltage)  
Max Luminance (full-scale)  
Min Luminance  
0.665  
0.700  
0.000  
0.770  
1, 3, 4 (black video  
level voltage)  
V
LSB Current  
73.2  
A
4, 5  
1, 6  
1, 6  
Integral Linearity (INL)  
Differential Linearity (DNL)  
-1.0  
-1.0  
+1.0  
+1.0  
LSB  
LSB  
Video channel-channel voltage amplitude  
mismatch  
6
%
7
Monotonicity  
Ensured  
NOTES:  
1. Measured at each R, G, B termination according to the VESA Test Procedure – Evaluation of Analog  
Display Graphics Subsystems Proposal (Version 1, Draft 4, December 1, 2000).  
2. Maximum steady-state amplitude  
3. Minimum steady-state amplitude  
4. Defined for a double 75-  
5. Set by external reference resistor value.  
termination.  
6. INL and DNL measured and calculated according to VESA Video Signal Standards.  
7.  
Max full-scale voltage difference among R, G, B outputs (percentage of steady-state full-scale voltage).  
§
270  
Ballout and Package Information  
12 Ballout and Package Information  
This chapter provides the ballout and package information.  
12.1  
Ballout  
Figure 12-1 through Figure 12-3 show the GMCH ballout for platforms using DDR2 system  
memory, as viewed from the top side of the package.  
Note: Balls that are listed as RSV are reserved. Board traces should Not be routed to these balls.  
Note: Some balls marked as reserved (RSV) are used in XOR testing. See Chapter 0 for details.  
Note: Some balls marked as reserved (RSV) can be used as test points. These are marked as RSV_TPx.  
Note: Balls that are listed as NC are No Connects.  
271  
Ballout and Package Information  
Figure 12-1. Intel® 82945G GMCH Ballout Diagram (Top View – Columns 43–30)  
43  
NC  
NC  
42  
41  
40  
39  
38  
37  
36  
35  
34  
33  
32  
31  
30  
BC  
BB  
BA  
AY  
AW  
AV  
AU  
AT  
AR  
AP  
AN  
AM  
AL  
AK  
AJ  
AH  
AG  
AF  
AE  
AD  
AC  
AB  
AA  
Y
NC  
VCCSM  
SODT_A3  
SCS_B0#  
SMA_A13  
VCCSM  
VCCSM  
SWE_A#  
SCS_A2#  
SBS_A0  
VCCSM  
VCCSM  
BC  
BB  
BA  
AY  
AW  
AV  
AU  
AT  
AR  
AP  
AN  
AM  
AL  
AK  
AJ  
AH  
AG  
AF  
AE  
AD  
AC  
AB  
AA  
Y
VCCSM  
VSS  
VSS  
VSS  
SCS_A0#  
SCAS_A#  
SODT_A2  
SODT_A0  
VSS  
VSS  
SCLK_A0 SCLK_A3#  
SMA_A2  
SMA_A3  
SMA_A4  
SCS_B2#  
VCCSM  
SCS_B1#  
SCS_A1#  
SODT_A1  
SRAS_A#  
SBS_A1  
VCCSM  
SMA_A0  
SCLK_A3  
VCCSM  
SODT_B0  
SMA_B13  
VCCSM  
SDQ_A45  
SCS_A3#  
SMA_A10 SCLK_A0#  
SMA_A1  
SDQ_A36  
VSS  
SCS_B3#  
SODT_B1  
SODT_B3  
VCCSM  
VCCSM  
VCCSM  
SDQ_B39  
VSS  
SODT_B2  
SDQ_A34  
SDQ_B45  
SDQS_A4# SDQ_A33  
SDQ_A44  
SDQ_A40  
SDQ_A35  
SDQ_A39  
SDQS_A4  
VSS  
SDM_A4  
SDQ_A38  
VSS  
SDQ_A37  
VSS  
VSS  
SDQ_A42  
VSS  
SDQ_A41  
SDQS_A5  
VSS  
VSS  
SDM_B5  
VSS  
VSS  
SDQ_B44  
SDQ_B40  
SDQ_B34  
SDQ_B38  
VSS  
SDQ_A46 SDQS_A5#  
SDQ_A47  
SDM_A5  
SDQ_B41  
SDQS_B5  
VSS  
SDQ_A32  
SDQ_B42  
VSS  
SDQ_A53  
SDQ_A49  
SDQ_A52  
SDQ_A48  
SDQ_A43  
VSS  
RSV  
SDQ_B46  
SCLK_B2  
VSS  
VSS  
SDQS_B5# SDQ_B47  
SDQ_B35  
SDQ_B52  
SCLK_B2# SDQ_B43  
SDQ_B48  
VSS  
VSS  
SCLK_A2 SCLK_A2#  
RSV  
VSS  
VSS  
SDM_B6  
SCLK_B5  
VSS  
SCLK_B5#  
VSS  
SDQ_B49  
VSS  
SDQ_B53  
VSS  
SCLK_A5#  
VSS  
VSS  
SCLK_A5  
SDM_A6  
SDQS_A6 SDQS_A6#  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
SDQ_B54  
SDQ_B60  
SDQS_B6  
SDQ_B51  
VSS  
VSS  
SDQS_B6#  
SDQ_B50  
VSS  
RSV  
VSS  
VCC  
SDQ_A55  
SDQ_A60  
VSS  
SDQ_A54  
SDQ_A61  
SDQ_A50  
SDQ_B61  
SDQ_A51  
SDQ_A56  
SDM_A7  
SDQ_A57  
VSS  
SDM_B7  
VSS  
SDQS_B7#  
VSS  
VSS  
VSS  
SDQS_B7  
VSS  
VSS  
SDQ_B57  
RSV  
VSS  
SDQ_B55  
SDQ_B56  
RSV  
VSS  
RSV  
RSV  
SDQS_A7 SDQS_A7#  
SDQ_B63  
SDQ_B62  
SDQ_A63  
RSV  
SDQ_A62  
HBREQ0#  
SDQ_A59  
HEDRDY#  
HTRDY#  
SDQ_A58  
VSS  
RSV  
HA29#  
VSS  
VSS  
RSV  
VSS  
RSV  
VSS  
RSV  
SDQ_B59  
SDQ_B58  
VSS  
VSS  
RSV  
RSV  
HRS1#  
VSS  
VSS  
HA28#  
HA27#  
HA31#  
W
HADS#  
HA25#  
HDBSY#  
VSS  
HHITM#  
HDRDY#  
HHIT#  
W
V
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
HADSTB1#  
HA26#  
VSS  
HA22#  
VSS  
HA30#  
HA24#  
RSV  
VSS  
RSV  
RSV  
V
U
HLOCK#  
HRS0#  
HBNR#  
HA19#  
HA23#  
U
T
HRS2#  
T
R
VSS  
HA21#  
VSS  
HA18#  
HA20#  
VSS  
HA10#  
HA17#  
HA11#  
VSS  
VSS  
VSS  
R
P
HD2  
HA14#  
HD3  
HD0  
HD4  
HD7  
HDEFER#  
P
N
VSS  
HDSTBN0#  
VSS  
VSS  
HD1  
HA16#  
HA13#  
HA15#  
VSS  
VSS  
HA9#  
VSS  
HA12#  
HA8#  
VSS  
VSS  
HCLKP  
VSS  
N
M
HD5  
HD6  
HADSTB0#  
HD33  
M
L
VSS  
HD30  
VSS  
L
K
HD8  
HDSTBP0# HDINV0#  
HD10  
VSS  
HA4#  
VSS  
VSS  
HREQ2#  
HA6#  
HD18  
VSS  
HD27  
HD34  
HD31  
HD32  
VSS  
K
J
HA5#  
HA3#  
HA7#  
HD25  
VSS  
J
H
HD23  
H
G
HD11  
VSS  
HD13  
HD12  
HD14  
HD50  
HD9  
VSS  
HREQ3#  
HD16  
VSS  
HDSTBP1#  
NC  
HDSTBN1#  
VSS  
VSS  
G
F
HD15  
VSS  
HPCREQ#  
HD29  
VSS  
HD37  
HD48  
F
E
HREQ4#  
HBPRI#  
NC  
HREQ0#  
HREQ1#  
HD20  
HD17  
HDSTBP3#  
HD56  
E
D
HD19  
HD52  
HD21  
HD53  
HD51  
HD54  
HD61  
HD60  
HDINV3#  
HD63  
HCPURST#  
HD62  
D
C
VSS  
HD22  
VSS  
40  
HD24  
HD55  
HD26  
VSS  
35  
HD57  
HD59  
HD58  
VSS  
31  
C
B
NC  
RSV  
43  
NC  
NC  
VSS  
HDINV1#  
38  
HDSTBN3#  
HD28  
VSS  
HD49  
33  
B
A
NC  
A
42  
41  
39  
37  
36  
34  
32  
30  
272  
Ballout and Package Information  
Figure 12-2. Intel® 82945G GMCH Ballout Diagram (Top View – Columns 29–16)  
29  
28  
27  
26  
25  
24  
23  
22  
21  
20  
19  
18  
17  
16  
BC  
BB  
BA  
AY  
AW  
AV  
AU  
AT  
AR  
AP  
AN  
AM  
AL  
AK  
AJ  
AH  
AG  
AF  
AE  
AD  
AC  
AB  
AA  
Y
SMA_A6  
VCCSM  
VCCSM  
SMA_A12  
SBS_A2  
SCKE_A2  
VCCSM  
VCCSM  
SMA_B0  
SMA_B4  
VCCSM  
VCCSM  
SMA_B9  
SMA_B7  
RSV  
BC  
BB  
BA  
AY  
AW  
AV  
AU  
AT  
AR  
AP  
AN  
AM  
AL  
AK  
AJ  
AH  
AG  
AF  
AE  
AD  
AC  
AB  
AA  
Y
SMA_A9  
SMA_A5  
SMA_A7  
SMA_A11  
NC  
SCKE_A0  
SCKE_A3  
SCKE_A1  
SWE_B#  
SMA_B1  
SMA_B2  
SMA_B3  
VCCSM  
VCCSM  
VSS  
VSS  
SMA_B11  
SMA_B12  
SBS_B2  
RSV  
VCCSM  
SRAS_B# SMA_B10  
SBS_B1  
SBS_B0  
VCCSM  
SMA_B8  
SMA_B5  
SMA_A8  
SCAS_B#  
VCCSM  
SDQ_B26  
VSS  
SMA_B6  
VCCSM  
SDQ_A26  
VSS  
SCKE_B1  
VCCSM  
SDQS_B4#  
VSS  
NC  
NC  
RSV  
VCCSM  
SDQS_A3  
VSS  
VSS  
SDQ_B32  
VSS  
VSS  
SDQS_B3  
VSS  
VSS  
SDQS_B4  
SDM_B4  
VSS  
VSS  
SDQ_B31  
VSS  
VSS  
SDQ_A31  
VSS  
VSS  
SDQ_B37  
SDQ_B36  
VSS  
SCLK_B3#  
SCLK_B3  
VSS  
SDQS_B3#  
SDM_B3  
VSS  
SDQ_B29  
SDQ_B28  
VSS  
SDQS_A3#  
SDM_A3  
VSS  
SDQ_A29  
SDQ_A28  
VSS  
SDQ_B30  
VSS  
SDQ_A30  
VSS  
SDQ_B33  
SCLK_B0  
RSV  
SCLK_B0#  
VSS  
SDQ_B27  
RSV  
SDQ_B24  
VSS  
SDQ_B25  
VSS  
SDQ_A27  
VSS  
SDQ_A24  
RSV  
SDQ_A25  
VSS  
SDQ_B19  
RSV_TP1  
RSV_TP0  
VCC  
VSS  
RSV  
VSS  
VSS  
RSV_TP2  
RSV  
RSV  
VCC  
RSV_TP3  
VCC  
RSV  
RSV  
RSV  
RSV  
RSV  
VCC  
RSV  
VCC  
RSV  
VCC  
VCC  
VSS  
VCC  
VCC  
VSS  
VCC  
VCC  
VCC  
RSV  
RSV  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
VCC  
RSV  
VCC  
VSS  
VCC  
VSS  
VCC  
VSS  
VCC  
VSS  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
VCC  
VSS  
VCC  
VSS  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
VCC  
VCC  
VCC  
VSS  
VCC  
VCC  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
VCC  
VSS  
VCC  
VSS  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
VCC  
VCC  
VCC  
VSS  
VCC  
VCC  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VSS  
VSS  
VSS  
VSS  
W
W
V
VSS  
VSS  
V
U
U
T
T
R
VSS  
VSS  
RSV  
VSS  
VSS  
VSS  
VCC  
VSS  
VCC  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
R
P
P
N
VSS  
VSS  
VSS  
VSS  
RSV_TP6  
VSS  
DDC_CLK1  
VSS  
DDC_DATA1  
ICH_SYNC#  
RSV_TP5  
ALLZTEST  
BLUE#1  
BLUE1  
VCC  
N
M
HCLKN  
VSS  
HD35  
HD40  
VSS  
HDSTBN2#  
VSS  
HD41  
VSS  
VCC  
M
L
RSV_TP4  
EXP_SLR  
VSS  
BSEL2  
VSS  
VSS  
L
K
HD36  
VSS  
HD43  
HD42  
VSS  
HD46  
VSS  
GREEN1  
GREEN#1  
VSS  
K
J
HDSTBP2#  
VSS  
EXTTS#  
XORTEST  
VSS  
J
H
HD38  
VSS  
HD45  
VSS  
BSEL1  
VSS  
H
G
VSS  
HD44  
VSS  
VSS  
RED#1  
RED1  
VSS  
G
F
HD39  
HDINV2#  
VTT  
HD47  
VTT  
BSEL0  
VSS  
EXP_EN  
VSS  
VSS  
F
E
VTT  
VTT  
VSS  
E
HACCVRE  
F
D
C
HDVREF  
HSCOMP  
HSWING  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VSS  
VSS  
VCC2  
HSYNC1  
VSYNC1  
VSS  
D
C
VCCA_  
HPLL  
VCCA_  
DPLLA1  
VTT  
VTT  
VSS  
VSS  
VCCA_DAC  
VCCA_DAC  
VCCA_  
SMPLL  
VCCA_  
DPLLB1  
VCCA_  
EXPPLL  
B
A
VSS  
VTT  
VSS  
GCLKN  
B
A
HRCOMP  
28  
VSS  
26  
VTT  
24  
VSS  
22  
REFSET1  
20  
VSSA_DAC  
18  
VSS  
16  
29  
27  
25  
23  
21  
19  
17  
NOTES:  
1.  
This analog display signal ball is reserved (RSV) on the 82945P/82945PL MCH component.  
273  
Ballout and Package Information  
Figure 12-3. Intel® 82945G GMCH Ballout Diagram (Top View – Columns 15–1)  
15  
14  
13  
12  
11  
10  
9
8
7
6
5
4
3
2
NC  
1
BC  
BB  
BA  
AY  
AW  
VCCSM  
SCKE_B3  
SCKE_B2  
SDQ_A22  
VSS  
VSS  
SDQ_A14  
VSS  
VSS  
NC  
NC  
BC  
BB  
BA  
AY  
AW  
VSS  
SCKE_B0  
RSV  
SDQ_A19  
SDQ_A18  
SDQ_A23  
SDQ_A16  
SDQ_B10  
VSS  
SDM_A2  
SDQ_A21  
SDQ_A11  
SDQ_A10  
SDQ_A15  
SDM_B1  
SDQS_B1  
SDQ_B8  
SCLK_A1# SDQS_A1#  
VSS  
NC  
SDQS_A2# SDQ_A20  
SDQ_A17  
SCLK_A4#  
SCLK_A1  
VSS  
SDQS_A1  
SDQ_A9  
SDQ_A8  
NC  
SDQS_A2  
SCLK_A4  
SDM_A1  
NC  
VSS  
VCCSM  
VCCSM  
SDQS_B2  
VSS  
VSS  
VSS  
SCLK_B1#  
SCLK_B1  
VSS  
SDQ_A13  
SDQ_A3  
AV SDQ_B18  
AU VSS  
AT SDQ_B23  
AR VSS  
AP SDQ_B22  
AN VSS  
AM SDQ_B16  
SDQ_B9  
VSS  
VSS  
SDQ_A12 AV  
SCLK_B4  
SCLK_B4#  
SDQ_A6  
SDQS_A0  
SDQ_A2  
SDQ_A7  
AU  
AT  
SDQS_B2#  
SDQ_B21  
SDM_B2  
VSS  
VSS  
SDQ_B14  
VSS  
SDQ_B15 SDQS_B1#  
SDQ_B13  
VSS  
VSS  
SDQ_B12  
VSS  
SDM_A0  
SDQ_A0  
SDQS_A0#  
SDQ_A1  
VSS  
VSS  
SDQ_A4  
VSS  
AR  
AP  
AN  
AM  
AL  
VSS  
SDQ_B3  
SDQ_B2  
SDQ_B7  
SDQ_A5  
VSS  
SDQ_B20  
SDQ_B17  
VSS  
SDQ_B11  
SDM_B0  
SDQ_B6  
VSS  
VSS  
SDQS_B0  
SDQ_B1  
VSS  
VSS  
SDQS_B0#  
SDQ_B0  
VSS  
SMVREF0 SOCOMP1 SMVREF1  
AL  
AK  
AJ  
VSS  
VCC  
VCC  
VSS  
SDQ_B5  
SRCOMP0  
VSS  
VCC  
VSS  
VCC  
VCC  
VCC  
VCC  
AK  
AJ  
VCC  
RSTIN#  
SDQ_B4  
VSS  
PWROK  
SOCOMP0  
VSS  
SRCOMP1  
VCC  
AH  
AG  
AF  
AE  
AD  
VCC  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
AH  
AG  
AF  
AE  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VSS  
VCC  
VSS  
VCC_EXP VCC_EXP VCC_EXP  
VCC  
VCC  
VCC  
VSS  
VSS  
VCC_EXP  
VSS  
VCC_EXP  
VSS  
VSS  
VCC_EXP  
VSS  
VSS  
VCC_EXP VCC_EXP VCC_EXP  
VCC_EXP VCC_EXP DMI_TXN3  
VCC_EXP VCC_EXP AD  
EXP_  
COMPO  
EXP_  
COMPI  
AC  
VCC_EXP  
DMI_RXP3 DMI_RXN3  
VSS  
VSS  
AC  
AB  
AA  
DMI_TXP3  
VSS  
VSS  
DMI_TXN1 AB  
AA  
VCC  
VCC  
VSS  
VSS  
VCC_EXP  
VCC_EXP  
VSS  
VSS  
VSS  
DMI_RXN1 DMI_RXP1  
VSS  
DMI_RXN2 DMI_RXP2 VCC_EXP DMI_TXN2  
DMI_TXP1  
EXP_  
RXN15  
EXP_  
VSS  
Y
DMI_RXN0 DMI_RXP0  
VSS  
VSS  
DMI_TXP2  
VSS  
DMI_TXN0  
Y
RXP15  
W
V
EXP_TXN15  
VSS  
DMI_TXP0  
VSS  
W
V
VCC  
VCC  
VSS  
VSS  
VCC_EXP  
VCC_EXP  
VSS  
VSS  
VSS  
VCC_EXP VCC_EXP  
VSS  
VCC_EXP VCC_EXP VCC_EXP  
EXP_TXP15  
EXP_TXN14  
EXP_  
RXP12  
EXP_  
VSS  
U
T
VCC_EXP VCC_EXP VCC_EXP  
VSS  
EXP_TXN13  
EXP_TXP13  
VSS  
EXP_TXP14  
VSS  
U
T
RXN12  
EXP_TXN12  
EXP_TXN11  
EXP_  
RXP13  
EXP_  
RXN13  
R
VCC  
VSS  
VSS  
RSV  
RSV  
VSS  
VSS  
VSS  
VCC_EXP  
VSS  
VCC_EXP VCC_EXP  
VSS  
VSS  
VSS  
VCC_EXP  
R
EXP_  
RXP14  
P
N
M
L
VSS  
EXP_TXP12  
VSS  
P
N
M
L
EXP_  
RXN14  
VSS  
VSS  
VSS  
VSS  
VCC_EXP VCC_EXP VCC_EXP VCC_EXP  
VSS  
VSS  
VCC_EXP  
VCC_EXP  
VSS  
EXP_  
RXN10  
EXP_  
RXP10  
RSV  
VSS  
VSS  
EXP_TXN10  
EXP_TXP10  
EXP_TXN9  
VSS  
EXP_TXP11  
VSS  
EXP_  
RXN11  
VSS  
VSS  
EXP_  
RXP11  
K
VSS  
EXP_RXP8 EXP_RXN8  
EXP_RXP4  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
K
J
DREFCLKP  
DREFCLKN  
VSS  
EXP_RXP2  
EXP_RXN2  
VSS  
VSS  
VSS  
VSS  
EXP_RXN4  
VSS  
EXP_RXN7  
EXP_TXP9  
VSS  
EXP_TXN8  
J
H
G
H
G
EXP_RXP0  
VSS  
VSS  
EXP_RXP7  
VSS  
VSS  
EXP_RXN9  
EXP_RXP9  
VSS  
EXP_TXP8  
VSS  
SDVO_  
F
E
VSS  
VSS  
EXP_RXN0  
VSS  
EXP_RXN3 EXP_RXN5  
EXP_RXP5  
EXP_TXN7  
VSS  
F
E
CTRLDATA1  
SDVO_  
EXP_RXP3  
VSS  
VSS  
VSS  
VSS  
VSS  
EXP_TXP7  
CTRLCLK1  
D
C
B
A
EXP_TXP0  
VSS  
EXP_RXN1 EXP_RXP1  
VSS  
EXP_TXP5 EXP_TXN5  
VSS  
VSS  
VSS  
EXP_RXN6  
VSS  
VSS  
NC  
D
C
B
A
EXP_TXN0  
VSS  
EXP_TXP3 EXP_TXN3  
EXP_RXP6  
GCLKP  
EXP_TXN1  
VSS  
EXP_TXP2  
11  
EXP_TXN2  
VSS  
EXP_TXP4  
9
EXP_TXN4  
VSS  
EXP_TXP6  
6
EXP_TXN6  
VSS  
VSS  
4
NC  
NC  
EXP_TXP1  
13  
15  
14  
12  
10  
8
7
5
3
2
1
NOTES:  
1.  
This analog display signal ball is reserved on the 82945P/82945PL MCH component.  
274  
Ballout and Package Information  
12.2  
Ballout Table  
Table 12-1 lists the Intel® 82945G/82945GC/82945GZ GMCH and Intel® 82945P/82945PL MCH  
ballout in alphabetical order by signal name.  
Table 12-1. Intel® 82945G//82945GZ/82945GC/82945P/82945PL (G)MCH Ballout Sorted by  
Signal Name  
Intel® 82945GZ  
(82945GC) GMCH Signal  
Name  
Intel® 82945P  
/82945PL MCH Signal  
Name  
Intel® 82945G GMCH  
Signal Name  
Ball #  
ALLZTEST  
BLUE  
ALLZTEST  
BLUE  
ALLZTEST  
RSV  
K18  
H18  
J18  
BLUE#  
BLUE#  
RSV  
BSEL0  
BSEL0  
BSEL0  
F21  
H21  
L20  
N20  
N18  
Y8  
BSEL1  
BSEL1  
BSEL1  
BSEL2  
BSEL2  
BSEL2  
DDC_CLK  
DDC_DATA  
DMI_RXN0  
DMI_RXN1  
DMI_RXN2  
DMI_RXN3  
DMI_RXP0  
DMI_RXP1  
DMI_RXP2  
DMI_RXP3  
DMI_TXN0  
DMI_TXN1  
DMI_TXN2  
DMI_TXN3  
DMI_TXP0  
DMI_TXP1  
DMI_TXP2  
DMI_TXP3  
DREFCLKN  
DREFCLKP  
EXP_COMPI  
EXP_COMPO  
EXP_EN  
DDC_CLK  
DDC_DATA  
DMI_RXN0  
DMI_RXN1  
DMI_RXN2  
DMI_RXN3  
DMI_RXP0  
DMI_RXP1  
DMI_RXP2  
DMI_RXP3  
DMI_TXN0  
DMI_TXN1  
DMI_TXN2  
DMI_TXN3  
DMI_TXP0  
DMI_TXP1  
DMI_TXP2  
DMI_TXP3  
DREFCLKN  
DREFCLKP  
RSV (EXP_COMPI)  
RSV (EXP_COMP0)  
EXP_EN  
RSV  
RSV  
DMI_RXN0  
DMI_RXN1  
DMI_RXN2  
DMI_RXN3  
DMI_RXP0  
DMI_RXP1  
DMI_RXP2  
DMI_RXP3  
DMI_TXN0  
DMI_TXN1  
DMI_TXN2  
DMI_TXN3  
DMI_TXP0  
DMI_TXP1  
DMI_TXP2  
DMI_TXP3  
DREFCLKN  
DREFCLKP  
EXP_COMPI  
EXP_COMPO  
EXP_EN  
AA10  
AA7  
AC8  
Y7  
AA9  
AA6  
AC9  
Y1  
AB1  
AA4  
AC4  
W2  
AA2  
Y4  
AB3  
H15  
J15  
AC11  
AC12  
F20  
F12  
D12  
EXP_RXN0  
EXP_RXN1  
RSV (EXP_RXN0)  
RSV (EXP_RXN1)  
EXP_RXN0  
EXP_RXN1  
275  
Ballout and Package Information  
EXP_RXN2  
EXP_RXN3  
EXP_RXN4  
EXP_RXN5  
EXP_RXN6  
EXP_RXN7  
EXP_RXN8  
EXP_RXN9  
RSV (EXP_RXN2)  
RSV (EXP_RXN3)  
RSV (EXP_RXN4)  
RSV (EXP_RXN5)  
RSV (EXP_RXN6)  
RSV (EXP_RXN7)  
RSV (EXP_RXN8)  
RSV (EXP_RXN9)  
EXP_RXN2  
EXP_RXN3  
EXP_RXN4  
EXP_RXN5  
EXP_RXN6  
EXP_RXN7  
EXP_RXN8  
EXP_RXN9  
H13  
F10  
H10  
F9  
D3  
J6  
K8  
G4  
SDVOC_INT-  
(EXP_RXN10/  
SDVOC_INT-)  
EXP_RXN10/  
SDVOC_INT-  
EXP_RXN10  
M7  
EXP_RXN11  
EXP_RXN12  
RSV (EXP_RXN11)  
RSV (EXP_RXN12)  
EXP_RXN11  
EXP_RXN12  
L1  
U10  
SDVO_STALL-  
(EXP_RXN13/  
SDVO_STALL-)  
EXP_RXN13/  
SDVO_STALL-  
EXP_RXN13  
EXP_RXN14  
EXP_RXN15  
R7  
SDVOB_INT-  
(EXP_RXN14/  
SDVOB_INT-)  
EXP_RXN14/  
SDVOB_INT-  
N3  
SDVO_TVCLKIN-  
(EXP_RXN15/  
SDVO_TVCLKIN-)  
EXP_RXN15/  
SDVO_TVCLKIN-  
Y11  
EXP_RXP0  
EXP_RXP1  
EXP_RXP2  
EXP_RXP3  
EXP_RXP4  
EXP_RXP5  
EXP_RXP6  
EXP_RXP7  
EXP_RXP8  
EXP_RXP9  
RSV (EXP_RXP0)  
RSV (EXP_RXP1)  
RSV (EXP_RXP2)  
RSV (EXP_RXP3)  
RSV (EXP_RXP4)  
RSV (EXP_RXP5)  
RSV (EXP_RXP6)  
RSV (EXP_RXP7)  
RSV (EXP_RXP8)  
RSV (EXP_RXP9)  
EXP_RXP0  
EXP_RXP1  
EXP_RXP2  
EXP_RXP3  
EXP_RXP4  
EXP_RXP5  
EXP_RXP6  
EXP_RXP7  
EXP_RXP8  
EXP_RXP9  
G12  
D11  
J13  
E10  
J9  
F7  
C4  
G6  
K9  
F4  
SDVOC_INT+  
(EXP_RXP10/  
SDVOC_INT+)  
EXP_RXP10/  
SDVOC_INT+  
EXP_RXP10  
M6  
EXP_RXP11  
EXP_RXP12  
RSV (EXP_RXP11)  
RSV (EXP_RXP12)  
EXP_RXP11  
EXP_RXP12  
K2  
U11  
SDVO_STALL+  
(EXP_RXP13/  
SDVO_STALL+)  
EXP_RXP13/  
SDVO_STALL+  
EXP_RXP13  
EXP_RXP14  
EXP_RXP15  
R8  
SDVOB_INT+  
(EXP_RXP14/  
SDVOB_INT+)  
EXP_RXP14/  
SDVOB_INT+  
P4  
SDVO_TVCLKIN+  
(EXP_RXP15/  
SDVO_TVCLKIN+)  
EXP_RXP15/  
SDVO_TVCLKIN+  
Y10  
276  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
EXP_SLR  
EXP_SLR  
EXP_SLR  
K21  
C13  
B12  
B10  
C9  
EXP_TXN0  
EXP_TXN1  
EXP_TXN2  
EXP_TXN3  
EXP_TXN4  
EXP_TXN5  
EXP_TXN6  
EXP_TXN7  
RSV (EXP_TXN0)  
RSV (EXP_TXN1)  
RSV (EXP_TXN2)  
RSV (EXP_TXN3)  
RSV (EXP_TXN4)  
RSV (EXP_TXN5)  
RSV (EXP_TXN6)  
RSV (EXP_TXN7)  
EXP_TXN0  
EXP_TXN1  
EXP_TXN2  
EXP_TXN3  
EXP_TXN4  
EXP_TXN5  
EXP_TXN6  
EXP_TXN7  
B7  
D6  
B5  
F1  
SDVOC_CLK-  
(EXP_TXN8/  
SDVOC_CLK-  
EXP_TXN8/  
SDVOC_CLK-  
EXP_TXN8  
EXP_TXN9  
EXP_TXN10  
J1  
SDVOC_BLUE-  
(EXP_TXN9/  
SDVOC_BLUE-)  
EXP_TXN9/  
SDVOC_BLUE-  
K4  
M4  
SDVOC_GREEN-  
(EXP_TXN10/  
SDVOC_GREEN-)  
EXP_TXN10/  
SDVOC_GREEN-  
SDVOC_RED-/  
SDVOB_ALPHA-  
(EXP_TXN11/  
EXP_TXN11/  
EXP_TXN11  
N1  
SDVOC_RED-/  
SDVOB_ALPHA-  
SDVOC_RED-/  
SDVOB_ALPHA-)  
SDVOB_CLK-  
(EXP_TXN12/  
SDVOB_CLK-)  
EXP_TXN12/  
SDVOB_CLK-  
EXP_TXN12  
EXP_TXN13  
EXP_TXN14  
EXP_TXN15  
T1  
SDVOB_BLUE-  
(EXP_TXN13/  
SDVOB_BLUE-)  
EXP_TXN13/  
SDVOB_BLUE-  
U4  
V1  
W4  
SDVOB_GREEN-  
(EXP_TXN14/  
SDVOB_GREEN-)  
EXP_TXN14/  
SDVOB_GREEN-  
SDVOB_RED-  
(EXP_TXN15/  
SDVOB_RED-)  
EXP_TXN15/  
SDVOB_RED-  
EXP_TXP0  
EXP_TXP1  
EXP_TXP2  
EXP_TXP3  
EXP_TXP4  
EXP_TXP5  
EXP_TXP6  
EXP_TXP7  
RSV (EXP_TXP0)  
RSV (EXP_TXP1)  
RSV (EXP_TXP2)  
RSV (EXP_TXP3)  
RSV (EXP_TXP4)  
RSV (EXP_TXP5)  
RSV (EXP_TXP6)  
RSV (EXP_TXP7)  
EXP_TXP0  
EXP_TXP1  
EXP_TXP2  
EXP_TXP3  
EXP_TXP4  
EXP_TXP5  
EXP_TXP6  
EXP_TXP7  
D14  
A13  
A11  
C10  
A9  
D7  
A6  
E2  
SDVOC_CLK+  
(EXP_TXP8/  
SDVOC_CLK+)  
EXP_TXP8/  
SDVOC_CLK+  
EXP_TXP8  
G2  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
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Ballout and Package Information  
SDVOC_BLUE+  
(EXP_TXP9/  
SDVOC_BLUE+)  
EXP_TXP9/  
SDVOC_BLUE+  
EXP_TXP9  
J3  
L4  
SDVOC_GREEN+  
(EXP_TXP10/  
SDVOC_GREEN+)  
EXP_TXP10/  
SDVOC_GREEN+  
EXP_TXP10  
SDVOC_RED+/  
SDVOB_ALPHA+  
(EXP_TXP11/  
EXP_TXP11/  
EXP_TXP11  
M2  
SDVOC_RED+/  
SDVOB_ALPHA+  
SDVOC_RED+/  
SDVOB_ALPHA+)  
SDVOB_CLK+  
(EXP_TXP12/  
SDVOB_CLK+)  
EXP_TXP12/  
SDVOB_CLK+  
EXP_TXP12  
EXP_TXP13  
EXP_TXP14  
EXP_TXP15  
P2  
T4  
U2  
V3  
SDVOB_BLUE+  
(EXP_TXP13/  
SDVOB_BLUE+)  
EXP_TXP13/  
SDVOB_BLUE+  
SDVOB_GREEN+  
(EXP_TXP14/  
SDVOB_GREEN+)  
EXP_TXP14/  
SDVOB_GREEN+  
SDVOB_RED+  
(EXP_TXP15/  
SDVOB_RED+)  
EXP_TXP15/  
SDVOB_RED+  
EXTTS#  
GCLKN  
GCLKP  
GREEN  
GREEN#  
HA3#  
EXTTS#  
GCLKN  
GCLKP  
GREEN  
GREEN#  
HA3#  
EXTTS#  
GCLKN  
GCLKP  
RSV  
J20  
B16  
B14  
K17  
J17  
RSV  
HA3#  
J39  
HA4#  
HA4#  
HA4#  
K38  
J42  
HA5#  
HA5#  
HA5#  
HA6#  
HA6#  
HA6#  
K35  
J37  
HA7#  
HA7#  
HA7#  
HA8#  
HA8#  
HA8#  
M34  
N35  
R33  
N32  
N34  
M38  
N42  
N37  
N38  
R32  
R36  
U37  
R35  
HA9#  
HA9#  
HA9#  
HA10#  
HA11#  
HA12#  
HA13#  
HA14#  
HA15#  
HA16#  
HA17#  
HA18#  
HA19#  
HA20#  
HA10#  
HA11#  
HA12#  
HA13#  
HA14#  
HA15#  
HA16#  
HA17#  
HA18#  
HA19#  
HA20#  
HA10#  
HA11#  
HA12#  
HA13#  
HA14#  
HA15#  
HA16#  
HA17#  
HA18#  
HA19#  
HA20#  
278  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
HA21#  
HA22#  
HA23#  
HA24#  
HA25#  
HA26#  
HA27#  
HA28#  
HA29#  
HA30#  
HA31#  
HACCVREF  
HADS#  
HADSTB0#  
HADSTB1#  
HBNR#  
HBPRI#  
HBREQ0#  
HCLKN  
HCLKP  
HCPURST#  
HD0  
HA21#  
HA22#  
HA23#  
HA24#  
HA25#  
HA26#  
HA27#  
HA28#  
HA29#  
HA30#  
HA31#  
HACCVREF  
HADS#  
HADSTB0#  
HADSTB1#  
HBNR#  
HBPRI#  
HBREQ0#  
HCLKN  
HCLKP  
HCPURST#  
HD0  
HA21#  
HA22#  
HA23#  
HA24#  
HA25#  
HA26#  
HA27#  
HA28#  
HA29#  
HA30#  
HA31#  
R38  
V33  
U34  
U32  
V42  
U35  
Y36  
Y38  
AA37  
V32  
Y34  
HACCVREF  
HADS#  
HADSTB0#  
HADSTB1#  
HBNR#  
HBPRI#  
HBREQ0#  
HCLKN  
HCLKP  
HCPURST#  
HD0  
D28  
W42  
M36  
V35  
U39  
D42  
AA41  
M29  
M31  
C30  
P41  
M39  
P42  
M42  
N41  
M40  
L40  
HD1  
HD1  
HD1  
HD2  
HD2  
HD2  
HD3  
HD3  
HD3  
HD4  
HD4  
HD4  
HD5  
HD5  
HD5  
HD6  
HD6  
HD6  
HD7  
HD7  
HD7  
M41  
K42  
G39  
J41  
HD8  
HD8  
HD8  
HD9  
HD9  
HD9  
HD10  
HD10  
HD10  
HD11  
HD11  
HD11  
G42  
G40  
G41  
F40  
F43  
F37  
E37  
J35  
HD12  
HD12  
HD12  
HD13  
HD13  
HD13  
HD14  
HD14  
HD14  
HD15  
HD15  
HD15  
HD16  
HD16  
HD16  
HD17  
HD17  
HD17  
HD18  
HD18  
HD18  
HD19  
HD19  
HD19  
D39  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
279  
Ballout and Package Information  
HD20  
HD21  
HD22  
HD23  
HD24  
HD25  
HD26  
HD27  
HD28  
HD29  
HD30  
HD31  
HD32  
HD33  
HD34  
HD35  
HD36  
HD37  
HD38  
HD39  
HD40  
HD41  
HD42  
HD43  
HD44  
HD45  
HD46  
HD47  
HD48  
HD49  
HD50  
HD51  
HD52  
HD53  
HD54  
HD55  
HD56  
HD57  
HD58  
HD59  
HD60  
HD20  
HD21  
HD22  
HD23  
HD24  
HD25  
HD26  
HD27  
HD28  
HD29  
HD30  
HD31  
HD32  
HD33  
HD34  
HD35  
HD36  
HD37  
HD38  
HD39  
HD40  
HD41  
HD42  
HD43  
HD44  
HD45  
HD46  
HD47  
HD48  
HD49  
HD50  
HD51  
HD52  
HD53  
HD54  
HD55  
HD56  
HD57  
HD58  
HD59  
HD60  
HD20  
HD21  
HD22  
HD23  
HD24  
HD25  
HD26  
HD27  
HD28  
HD29  
HD30  
HD31  
HD32  
HD33  
HD34  
HD35  
HD36  
HD37  
HD38  
HD39  
HD40  
HD41  
HD42  
HD43  
HD44  
HD45  
HD46  
HD47  
HD48  
HD49  
HD50  
HD51  
HD52  
HD53  
HD54  
HD55  
HD56  
HD57  
HD58  
HD59  
HD60  
C41  
B39  
B40  
H34  
C37  
J32  
B35  
J34  
B34  
F32  
L32  
J31  
H31  
M33  
K31  
M27  
K29  
F31  
H29  
F29  
L27  
M24  
J26  
K26  
G26  
H24  
K24  
F24  
E31  
A33  
E40  
D37  
C39  
D38  
D33  
C35  
D34  
C34  
B31  
C31  
C32  
280  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
HD61  
HD61  
HD61  
D32  
B30  
D30  
U42  
HD62  
HD62  
HD62  
HD63  
HD63  
HD63  
HDBSY#  
HDEFER#  
HDINV0#  
HDINV1#  
HDINV2#  
HDINV3#  
HDRDY#  
HDSTBN0#  
HDSTBN1#  
HDSTBN2#  
HDSTBN3#  
HDSTBP0#  
HDSTBP1#  
HDSTBP2#  
HDSTBP3#  
HDVREF  
HEDRDY#  
HHIT#  
HDBSY#  
HDEFER#  
HDINV0#  
HDINV1#  
HDINV2#  
HDINV3#  
HDRDY#  
HDSTBN0#  
HDSTBN1#  
HDSTBN2#  
HDSTBN3#  
HDSTBP0#  
HDSTBP1#  
HDSTBP2#  
HDSTBP3#  
HDVREF  
HEDRDY#  
HHIT#  
HDBSY#  
HDEFER#  
HDINV0#  
HDINV1#  
HDINV2#  
HDINV3#  
HDRDY#  
HDSTBN0#  
HDSTBN1#  
HDSTBN2#  
HDSTBN3#  
HDSTBP0#  
HDSTBP1#  
HDSTBP2#  
HDSTBP3#  
HDVREF  
HEDRDY#  
HHIT#  
P40  
K40  
A38  
E29  
B32  
V41  
L43  
G34  
M26  
B37  
K41  
F35  
J27  
E34  
D27  
Y40  
U41  
W41  
U40  
F38  
A28  
E41  
D41  
K36  
G37  
E42  
T40  
Y43  
T43  
C27  
B27  
D17  
W40  
M18  
BC43  
BC42  
BC2  
HHITM#  
HLOCK#  
HPCREQ#  
HRCOMP  
HREQ0#  
HREQ1#  
HREQ2#  
HREQ3#  
HREQ4#  
HRS0#  
HHITM#  
HLOCK#  
HPCREQ#  
HRCOMP  
HREQ0#  
HREQ1#  
HREQ2#  
HREQ3#  
HREQ4#  
HRS0#  
HHITM#  
HLOCK#  
HPCREQ#  
HRCOMP  
HREQ0#  
HREQ1#  
HREQ2#  
HREQ3#  
HREQ4#  
HRS0#  
HRS1#  
HRS1#  
HRS1#  
HRS2#  
HRS2#  
HRS2#  
HSCOMP  
HSWING  
HSYNC  
HSCOMP  
HSWING  
HSYNC  
HSCOMP  
HSWING  
RSV  
HTRDY#  
ICH_SYNC#  
NC  
HTRDY#  
ICH_SYNC#  
NC  
HTRDY#  
ICH_SYNC#  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
281  
Ballout and Package Information  
NC  
NC  
NC  
BC1  
BB43  
BB2  
BB1  
BA2  
AW26  
AW2  
AV27  
AV26  
E35  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
NC  
C42  
NC  
NC  
NC  
C2  
NC  
NC  
NC  
B43  
NC  
NC  
NC  
B42  
NC  
NC  
NC  
B41  
NC  
NC  
NC  
B3  
NC  
NC  
NC  
B2  
NC  
NC  
NC  
A42  
PWROK  
RED  
RED#  
REFSET  
RSTIN#  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
PWROK  
RED  
RED#  
REFSET  
RSTIN#  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
PWROK  
RSV  
RSV  
RSV  
RSTIN#  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
AJ9  
F17  
G17  
A20  
AJ12  
V30  
AG29  
AJ29  
AK27  
AL26  
AJ21  
AL20  
AL29  
AJ26  
AJ23  
AK21  
AC30  
AA30  
V31  
U30  
AD31  
AF31  
Y33  
282  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
Y30  
RSV  
RSV  
AC34  
AD30  
BC16  
AY14  
AW18  
AW17  
AL39  
AK40  
AJ27  
AJ24  
AG27  
AG26  
AG25  
M11  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
A43  
RSV  
RSV  
R27  
RSV  
RSV  
U27  
RSV  
RSV  
M15  
RSV  
RSV  
L15  
RSV  
RSV  
AA38  
AA34  
AA42  
AA35  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV  
RSV_TP0  
RSV_TP1  
RSV_TP2  
RSV_TP3  
RSV_TP4  
RSV_TP5  
RSV_TP6  
SBS_A0  
SBS_A1  
SBS_A2  
SBS_B0  
SBS_B1  
SBS_B2  
SCAS_A#  
SCAS_B#  
SCKE_A0  
SCKE_A1  
RSV_TP0  
RSV_TP1  
RSV_TP2  
RSV_TP3  
RSV_TP4  
RSV_TP5  
RSV_TP6  
SBS_A0  
SBS_A1  
SBS_A2  
SBS_B0  
SBS_B1  
SBS_B2  
SCAS_A#  
SCAS_B#  
SCKE_A0  
SCKE_A1  
RSV_TP0  
RSV_TP1  
RSV_TP2  
RSV_TP3  
RSV_TP4  
RSV_TP5  
RSV_TP6  
SBS_A0  
AK17  
AL17  
AK23  
AK18  
L21  
L18  
N21  
BC33  
AY34  
BA26  
AW23  
AY23  
AY17  
BA37  
AY24  
BB25  
AY25  
SBS_A1  
SBS_A2  
SBS_B0  
SBS_B1  
SBS_B2  
SCAS_A#  
SCAS_B#  
SCKE_A0  
SCKE_A1  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
283  
Ballout and Package Information  
SCKE_A2  
SCKE_A3  
SCKE_B0  
SCKE_B1  
SCKE_B2  
SCKE_B3  
SCLK_A0  
SCLK_A0#  
SCLK_A1  
SCLK_A1#  
SCLK_A2  
SCLK_A2#  
SCLK_A3  
SCLK_A3#  
SCLK_A4  
SCLK_A4#  
SCLK_A5  
SCLK_A5#  
SCLK_B0  
SCLK_B0#  
SCLK_B1  
SCLK_B1#  
SCLK_B2  
SCLK_B2#  
SCLK_B3  
SCLK_B3#  
SCLK_B4  
SCLK_B4#  
SCLK_B5  
SCLK_B5#  
SCS_A0#  
SCS_A1#  
SCS_A2#  
SCS_A3#  
SCS_B0#  
SCS_B1#  
SCS_B2#  
SCS_B3#  
SDM_A0  
SCKE_A2  
SCKE_A3  
SCKE_B0  
SCKE_B1  
SCKE_B2  
SCKE_B3  
SCLK_A0  
SCLK_A0#  
SCLK_A1  
SCLK_A1#  
SCLK_A2  
SCLK_A2#  
SCLK_A3  
SCLK_A3#  
SCLK_A4  
SCLK_A4#  
SCLK_A5  
SCLK_A5#  
SCLK_B0  
SCLK_B0#  
SCLK_B1  
SCLK_B1#  
SCLK_B2  
SCLK_B2#  
SCLK_B3  
SCLK_B3#  
SCLK_B4  
SCLK_B4#  
SCLK_B5  
SCLK_B5#  
SCS_A0#  
SCS_A1#  
SCS_A2#  
SCS_A3#  
SCS_B0#  
SCS_B1#  
SCS_B2#  
SCS_B3#  
SDM_A0  
SCKE_A2  
SCKE_A3  
SCKE_B0  
SCKE_B1  
SCKE_B2  
SCKE_B3  
SCLK_A0  
SCLK_A0#  
SCLK_A1  
SCLK_A1#  
SCLK_A2  
SCLK_A2#  
SCLK_A3  
SCLK_A3#  
SCLK_A4  
SCLK_A4#  
SCLK_A5  
SCLK_A5#  
SCLK_B0  
SCLK_B0#  
SCLK_B1  
SCLK_B1#  
SCLK_B2  
SCLK_B2#  
SCLK_B3  
SCLK_B3#  
SCLK_B4  
SCLK_B4#  
SCLK_B5  
SCLK_B5#  
SCS_A0#  
SCS_A1#  
SCS_A2#  
SCS_A3#  
SCS_B0#  
SCS_B1#  
SCS_B2#  
SCS_B3#  
SDM_A0  
BC24  
BA25  
BA14  
AY16  
BA13  
BB13  
BB32  
AY32  
AY5  
BB5  
AK42  
AK41  
BA31  
BB31  
AY6  
BA5  
AH40  
AH43  
AM29  
AM27  
AV9  
AW9  
AL38  
AL36  
AP26  
AR26  
AU10  
AT10  
AJ38  
AJ36  
BB37  
BA39  
BA35  
AY38  
BA40  
AW41  
BA41  
AW40  
AR3  
SDM_A1  
SDM_A1  
SDM_A1  
AY2  
SDM_A2  
SDM_A2  
SDM_A2  
BB10  
284  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
SDM_A3  
SDM_A4  
SDM_A5  
SDM_A6  
SDM_A7  
SDM_B0  
SDM_B1  
SDM_B2  
SDM_B3  
SDM_B4  
SDM_B5  
SDM_B6  
SDM_B7  
SDQ_A0  
SDQ_A1  
SDQ_A2  
SDQ_A3  
SDQ_A4  
SDQ_A5  
SDQ_A6  
SDQ_A7  
SDQ_A8  
SDQ_A9  
SDQ_A10  
SDQ_A11  
SDQ_A12  
SDQ_A13  
SDQ_A14  
SDQ_A15  
SDQ_A16  
SDQ_A17  
SDQ_A18  
SDQ_A19  
SDQ_A20  
SDQ_A21  
SDQ_A22  
SDQ_A23  
SDQ_A24  
SDQ_A25  
SDQ_A26  
SDQ_A27  
SDM_A3  
SDM_A4  
SDM_A5  
SDM_A6  
SDM_A7  
SDM_B0  
SDM_B1  
SDM_B2  
SDM_B3  
SDM_B4  
SDM_B5  
SDM_B6  
SDM_B7  
SDQ_A0  
SDQ_A1  
SDQ_A2  
SDQ_A3  
SDQ_A4  
SDQ_A5  
SDQ_A6  
SDQ_A7  
SDQ_A8  
SDQ_A9  
SDQ_A10  
SDQ_A11  
SDQ_A12  
SDQ_A13  
SDQ_A14  
SDQ_A15  
SDQ_A16  
SDQ_A17  
SDQ_A18  
SDQ_A19  
SDQ_A20  
SDQ_A21  
SDQ_A22  
SDQ_A23  
SDQ_A24  
SDQ_A25  
SDQ_A26  
SDQ_A27  
SDM_A3  
SDM_A4  
SDM_A5  
SDM_A6  
SDM_A7  
SDM_B0  
SDM_B1  
SDM_B2  
SDM_B3  
SDM_B4  
SDM_B5  
SDM_B6  
SDM_B7  
SDQ_A0  
SDQ_A1  
SDQ_A2  
SDQ_A3  
SDQ_A4  
SDQ_A5  
SDQ_A6  
SDQ_A7  
SDQ_A8  
SDQ_A9  
AP18  
AT34  
AP39  
AG40  
AC40  
AL11  
AW7  
AP13  
AP23  
AR29  
AR38  
AJ39  
AD39  
AP3  
AP2  
AU3  
AV4  
AN1  
AP4  
AU5  
AU2  
AW3  
AY3  
SDQ_A10  
SDQ_A11  
SDQ_A12  
SDQ_A13  
SDQ_A14  
SDQ_A15  
SDQ_A16  
SDQ_A17  
SDQ_A18  
SDQ_A19  
SDQ_A20  
SDQ_A21  
SDQ_A22  
SDQ_A23  
SDQ_A24  
SDQ_A25  
SDQ_A26  
SDQ_A27  
BA7  
BB7  
AV1  
AW4  
BC6  
AY7  
AW12  
AY10  
BA12  
BB12  
BA9  
BB9  
BC11  
AY12  
AM20  
AM18  
AV20  
AM21  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
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Ballout and Package Information  
SDQ_A28  
SDQ_A29  
SDQ_A30  
SDQ_A31  
SDQ_A32  
SDQ_A33  
SDQ_A34  
SDQ_A35  
SDQ_A36  
SDQ_A37  
SDQ_A38  
SDQ_A39  
SDQ_A40  
SDQ_A41  
SDQ_A42  
SDQ_A43  
SDQ_A44  
SDQ_A45  
SDQ_A46  
SDQ_A47  
SDQ_A48  
SDQ_A49  
SDQ_A50  
SDQ_A51  
SDQ_A52  
SDQ_A53  
SDQ_A54  
SDQ_A55  
SDQ_A56  
SDQ_A57  
SDQ_A58  
SDQ_A59  
SDQ_A60  
SDQ_A61  
SDQ_A62  
SDQ_A63  
SDQ_B0  
SDQ_A28  
SDQ_A29  
SDQ_A30  
SDQ_A31  
SDQ_A32  
SDQ_A33  
SDQ_A34  
SDQ_A35  
SDQ_A36  
SDQ_A37  
SDQ_A38  
SDQ_A39  
SDQ_A40  
SDQ_A41  
SDQ_A42  
SDQ_A43  
SDQ_A44  
SDQ_A45  
SDQ_A46  
SDQ_A47  
SDQ_A48  
SDQ_A49  
SDQ_A50  
SDQ_A51  
SDQ_A52  
SDQ_A53  
SDQ_A54  
SDQ_A55  
SDQ_A56  
SDQ_A57  
SDQ_A58  
SDQ_A59  
SDQ_A60  
SDQ_A61  
SDQ_A62  
SDQ_A63  
SDQ_B0  
SDQ_A28  
SDQ_A29  
SDQ_A30  
SDQ_A31  
SDQ_A32  
SDQ_A33  
SDQ_A34  
SDQ_A35  
SDQ_A36  
SDQ_A37  
SDQ_A38  
SDQ_A39  
SDQ_A40  
SDQ_A41  
SDQ_A42  
SDQ_A43  
SDQ_A44  
SDQ_A45  
SDQ_A46  
SDQ_A47  
SDQ_A48  
SDQ_A49  
SDQ_A50  
SDQ_A51  
SDQ_A52  
SDQ_A53  
SDQ_A54  
SDQ_A55  
SDQ_A56  
SDQ_A57  
SDQ_A58  
SDQ_A59  
SDQ_A60  
SDQ_A61  
SDQ_A62  
SDQ_A63  
SDQ_B0  
AP17  
AR17  
AP20  
AT20  
AP32  
AV34  
AV38  
AU39  
AV32  
AT32  
AR34  
AU37  
AR41  
AR42  
AN43  
AM40  
AU41  
AU42  
AP41  
AN40  
AL41  
AL42  
AF39  
AE40  
AM41  
AM42  
AF41  
AF42  
AD40  
AD43  
AA39  
AA40  
AE42  
AE41  
AB41  
AB42  
AL6  
SDQ_B1  
SDQ_B1  
SDQ_B1  
AL8  
SDQ_B2  
SDQ_B2  
SDQ_B2  
AP8  
SDQ_B3  
SDQ_B3  
SDQ_B3  
AP9  
SDQ_B4  
SDQ_B4  
SDQ_B4  
AJ11  
286  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
SDQ_B5  
SDQ_B5  
SDQ_B5  
SDQ_B6  
SDQ_B7  
SDQ_B8  
SDQ_B9  
AL9  
SDQ_B6  
SDQ_B6  
AM10  
AP6  
AU7  
AV6  
SDQ_B7  
SDQ_B7  
SDQ_B8  
SDQ_B8  
SDQ_B9  
SDQ_B9  
SDQ_B10  
SDQ_B11  
SDQ_B12  
SDQ_B13  
SDQ_B14  
SDQ_B15  
SDQ_B16  
SDQ_B17  
SDQ_B18  
SDQ_B19  
SDQ_B20  
SDQ_B21  
SDQ_B22  
SDQ_B23  
SDQ_B24  
SDQ_B25  
SDQ_B26  
SDQ_B27  
SDQ_B28  
SDQ_B29  
SDQ_B30  
SDQ_B31  
SDQ_B32  
SDQ_B33  
SDQ_B34  
SDQ_B35  
SDQ_B36  
SDQ_B37  
SDQ_B38  
SDQ_B39  
SDQ_B40  
SDQ_B41  
SDQ_B42  
SDQ_B43  
SDQ_B44  
SDQ_B45  
SDQ_B10  
SDQ_B11  
SDQ_B12  
SDQ_B13  
SDQ_B14  
SDQ_B15  
SDQ_B16  
SDQ_B17  
SDQ_B18  
SDQ_B19  
SDQ_B20  
SDQ_B21  
SDQ_B22  
SDQ_B23  
SDQ_B24  
SDQ_B25  
SDQ_B26  
SDQ_B27  
SDQ_B28  
SDQ_B29  
SDQ_B30  
SDQ_B31  
SDQ_B32  
SDQ_B33  
SDQ_B34  
SDQ_B35  
SDQ_B36  
SDQ_B37  
SDQ_B38  
SDQ_B39  
SDQ_B40  
SDQ_B41  
SDQ_B42  
SDQ_B43  
SDQ_B44  
SDQ_B45  
SDQ_B10  
SDQ_B11  
SDQ_B12  
SDQ_B13  
SDQ_B14  
SDQ_B15  
SDQ_B16  
SDQ_B17  
SDQ_B18  
SDQ_B19  
SDQ_B20  
SDQ_B21  
SDQ_B22  
SDQ_B23  
SDQ_B24  
SDQ_B25  
SDQ_B26  
SDQ_B27  
SDQ_B28  
SDQ_B29  
SDQ_B30  
SDQ_B31  
SDQ_B32  
SDQ_B33  
SDQ_B34  
SDQ_B35  
SDQ_B36  
SDQ_B37  
SDQ_B38  
SDQ_B39  
SDQ_B40  
SDQ_B41  
SDQ_B42  
SDQ_B43  
SDQ_B44  
SDQ_B45  
AV12  
AM11  
AR5  
AR7  
AR12  
AR10  
AM15  
AM13  
AV15  
AM17  
AN12  
AR13  
AP15  
AT15  
AM24  
AM23  
AV24  
AM26  
AP21  
AR21  
AP24  
AT24  
AU27  
AN29  
AR31  
AM31  
AP27  
AR27  
AP31  
AU31  
AP35  
AP37  
AN32  
AL35  
AR35  
AU38  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
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Ballout and Package Information  
SDQ_B46  
SDQ_B47  
SDQ_B48  
SDQ_B49  
SDQ_B50  
SDQ_B51  
SDQ_B52  
SDQ_B53  
SDQ_B54  
SDQ_B55  
SDQ_B56  
SDQ_B57  
SDQ_B58  
SDQ_B59  
SDQ_B60  
SDQ_B61  
SDQ_B62  
SDQ_B63  
SDQS_A0  
SDQS_A0#  
SDQS_A1  
SDQS_A1#  
SDQS_A2  
SDQS_A2#  
SDQS_A3  
SDQS_A3#  
SDQS_A4  
SDQS_A4#  
SDQS_A5  
SDQS_A5#  
SDQS_A6  
SDQS_A6#  
SDQS_A7  
SDQS_A7#  
SDQS_B0  
SDQS_B0#  
SDQS_B1  
SDQS_B1#  
SDQS_B2  
SDQS_B2#  
SDQS_B3  
SDQ_B46  
SDQ_B47  
SDQ_B48  
SDQ_B49  
SDQ_B50  
SDQ_B51  
SDQ_B52  
SDQ_B53  
SDQ_B54  
SDQ_B55  
SDQ_B56  
SDQ_B57  
SDQ_B58  
SDQ_B59  
SDQ_B60  
SDQ_B61  
SDQ_B62  
SDQ_B63  
SDQS_A0  
SDQS_A0#  
SDQS_A1  
SDQS_A1#  
SDQS_A2  
SDQS_A2#  
SDQS_A3  
SDQS_A3#  
SDQS_A4  
SDQS_A4#  
SDQS_A5  
SDQS_A5#  
SDQS_A6  
SDQS_A6#  
SDQS_A7  
SDQS_A7#  
SDQS_B0  
SDQS_B0#  
SDQS_B1  
SDQS_B1#  
SDQS_B2  
SDQS_B2#  
SDQS_B3  
SDQ_B46  
SDQ_B47  
SDQ_B48  
SDQ_B49  
SDQ_B50  
SDQ_B51  
SDQ_B52  
SDQ_B53  
SDQ_B54  
SDQ_B55  
SDQ_B56  
SDQ_B57  
SDQ_B58  
SDQ_B59  
SDQ_B60  
SDQ_B61  
SDQ_B62  
SDQ_B63  
SDQS_A0  
SDQS_A0#  
SDQS_A1  
SDQS_A1#  
SDQS_A2  
SDQS_A2#  
SDQS_A3  
SDQS_A3#  
SDQS_A4  
SDQS_A4#  
SDQS_A5  
SDQS_A5#  
SDQS_A6  
SDQS_A6#  
SDQS_A7  
SDQS_A7#  
SDQS_B0  
SDQS_B0#  
SDQS_B1  
SDQS_B1#  
SDQS_B2  
SDQS_B2#  
SDQS_B3  
AM38  
AM34  
AL34  
AJ34  
AF32  
AF34  
AL31  
AJ32  
AG35  
AD32  
AC32  
AD34  
Y32  
AA32  
AF35  
AF37  
AC33  
AC35  
AU4  
AR2  
BA3  
BB4  
AY11  
BA10  
AU18  
AR18  
AU35  
AV35  
AP42  
AP40  
AG42  
AG41  
AC42  
AC41  
AM8  
AM6  
AV7  
AR9  
AV13  
AT13  
AU23  
288  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
SDQS_B3#  
SDQS_B4  
SDQS_B4#  
SDQS_B5  
SDQS_B5#  
SDQS_B6  
SDQS_B6#  
SDQS_B7  
SDQS_B7#  
SDVO_CTRLCLK  
SDVO_CTRLDATA  
SMVREF0  
SMVREF1  
SMA_A0  
SDQS_B3#  
SDQS_B4  
SDQS_B4#  
SDQS_B5  
SDQS_B5#  
SDQS_B6  
SDQS_B6#  
SDQS_B7  
SDQS_B7#  
SDVO_CTRLCLK  
SDVO_CTRLDATA  
SMVREF0  
SMVREF1  
SMA_A0  
SDQS_B3#  
AR23  
AT29  
AV29  
AP36  
AM35  
AG34  
AG32  
AD36  
AD38  
E15  
SDQS_B4  
SDQS_B4#  
SDQS_B5  
SDQS_B5#  
SDQS_B6  
SDQS_B6#  
SDQS_B7  
SDQS_B7#  
RSV  
RSV  
F15  
SMVREF0  
SMVREF1  
SMA_A0  
SMA_A1  
SMA_A2  
SMA_A3  
SMA_A4  
SMA_A5  
SMA_A6  
SMA_A7  
SMA_A8  
SMA_A9  
SMA_A10  
SMA_A11  
SMA_A12  
SMA_A13  
SMA_B0  
SMA_B1  
SMA_B2  
SMA_B3  
SMA_B4  
SMA_B5  
SMA_B6  
SMA_B7  
SMA_B8  
SMA_B9  
SMA_B10  
SMA_B11  
SMA_B12  
SMA_B13  
AM4  
AM2  
BA32  
AW32  
BB30  
BA30  
AY30  
BA27  
BC28  
AY27  
AY28  
BB27  
AY33  
AW27  
BB26  
BC38  
BB22  
BB21  
BA21  
AY21  
BC20  
AY19  
AY20  
BA18  
BA19  
BB18  
BA22  
BB17  
BA17  
AW42  
SMA_A1  
SMA_A1  
SMA_A2  
SMA_A2  
SMA_A3  
SMA_A3  
SMA_A4  
SMA_A4  
SMA_A5  
SMA_A5  
SMA_A6  
SMA_A6  
SMA_A7  
SMA_A7  
SMA_A8  
SMA_A8  
SMA_A9  
SMA_A9  
SMA_A10  
SMA_A11  
SMA_A12  
SMA_A13  
SMA_B0  
SMA_A10  
SMA_A11  
SMA_A12  
SMA_A13  
SMA_B0  
SMA_B1  
SMA_B1  
SMA_B2  
SMA_B2  
SMA_B3  
SMA_B3  
SMA_B4  
SMA_B4  
SMA_B5  
SMA_B5  
SMA_B6  
SMA_B6  
SMA_B7  
SMA_B7  
SMA_B8  
SMA_B8  
SMA_B9  
SMA_B9  
SMA_B10  
SMA_B11  
SMA_B12  
SMA_B13  
SMA_B10  
SMA_B11  
SMA_B12  
SMA_B13  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
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Ballout and Package Information  
SOCOMP0  
SOCOMP1  
SODT_A0  
SODT_A1  
SODT_A2  
SODT_A3  
SODT_B0  
SODT_B1  
SODT_B2  
SODT_B3  
SRAS_A#  
SRAS_B#  
SRCOMP0  
SRCOMP1  
SWE_A#  
SWE_B#  
VCC  
SOCOMP0  
SOCOMP1  
SODT_A0  
SODT_A1  
SODT_A2  
SODT_A3  
SODT_B0  
SODT_B1  
SODT_B2  
SODT_B3  
SRAS_A#  
SRAS_B#  
SRCOMP0  
SRCOMP1  
SWE_A#  
SWE_B#  
VCC  
SOCOMP0  
SOCOMP1  
SODT_A0  
SODT_A1  
SODT_A2  
SODT_A3  
SODT_B0  
SODT_B1  
SODT_B2  
SODT_B3  
SRAS_A#  
SRAS_B#  
SRCOMP0  
SRCOMP1  
SWE_A#  
SWE_B#  
VCC  
AJ8  
AM3  
AW37  
AY39  
AY37  
BB40  
AY42  
AV40  
AV43  
AU40  
BA34  
BA23  
AL5  
AJ6  
BB35  
BB23  
AJ20  
AJ18  
AJ17  
AJ15  
AG24  
AG23  
AG22  
AG21  
AG20  
AG19  
AG18  
AG17  
AG15  
AF29  
AF27  
AF26  
AF25  
AF23  
AF21  
AF19  
AF17  
AF15  
AE27  
AE26  
AE24  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
290  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
AE22  
AE20  
AE18  
AE17  
AD26  
AD25  
AD23  
AD21  
AD19  
AD17  
AD15  
AC27  
AC26  
AC24  
AC20  
AC18  
AC17  
AC15  
AB27  
AB26  
AB25  
AB24  
AB20  
AB19  
AB18  
AB17  
AA26  
AA24  
AA20  
AA19  
AA18  
AA17  
AA15  
Y27  
Y25  
Y23  
Y21  
Y19  
Y18  
Y17  
Y15  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
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VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
W27  
W26  
W24  
W22  
W20  
W19  
W18  
W17  
V27  
V25  
V23  
V22  
V21  
V20  
V19  
V18  
V17  
V15  
U26  
U25  
U24  
U23  
U22  
U21  
U20  
U19  
U18  
U17  
U15  
R24  
R23  
R21  
R20  
R18  
R17  
R15  
AK20  
AK15  
AK14  
AK4  
AK3  
292  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
VCC  
AK2  
AJ14  
AJ13  
AJ5  
AH4  
AH2  
AH1  
AG14  
AG13  
AG12  
AG11  
AG10  
AG9  
AG8  
AG7  
AG6  
AG5  
AG4  
AG3  
AG2  
AF30  
AF14  
AF13  
AF12  
AF11  
AF10  
AF9  
AF8  
AF7  
AF6  
AD14  
AC22  
AB23  
AB22  
AB21  
AA22  
P21  
P20  
P18  
P17  
N17  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
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Ballout and Package Information  
VCC  
VCC  
VCC  
M17  
AE4  
AE3  
AE2  
AD12  
AD10  
AD8  
AD6  
AD5  
AD4  
AD2  
AD1  
AC13  
AC6  
AC5  
AA13  
AA5  
Y13  
V13  
V10  
V9  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC2  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC2  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC_EXP  
VCC2  
V7  
V6  
V5  
U13  
U8  
U7  
U6  
R13  
R11  
R10  
R5  
N12  
N11  
N10  
N9  
N7  
N5  
D19  
C18  
B18  
VCCA_DAC  
VCCA_DAC  
VCCA_DAC  
VCCA_DAC  
VCCA_DAC  
VCCA_DAC  
294  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
VCCA_DPLLA  
VCCA_DPLLB  
VCCA_EXPPLL  
VCCA_HPLL  
VCCA_SMPLL  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VSS  
VCCA_DPLLA  
VCCA_DPLLB  
VCCA_EXPPLL  
VCCA_HPLL  
VCCA_SMPLL  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VSS  
RSV  
RSV  
C19  
B19  
VCCA_EXPPLL  
VCCA_HPLL  
VCCA_SMPLL  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VCCSM  
VSS  
B17  
C21  
B20  
BC40  
AY43  
BC35  
BC31  
BC26  
BC22  
BC18  
BC13  
BB42  
BB38  
BB33  
BB28  
BB24  
BB20  
BB16  
AY41  
AW35  
AW34  
AW31  
AW29  
AW24  
AW21  
AW20  
AW15  
AW13  
AV42  
AV31  
AV23  
AV21  
AV18  
BC4  
VSS  
VSS  
VSS  
AY1  
VSS  
VSS  
VSS  
AF24  
AF22  
AF20  
AF18  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
295  
Ballout and Package Information  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
AE25  
AE23  
AE21  
AE19  
AD29  
AD27  
AD24  
AD22  
AD20  
AD18  
AC29  
AC25  
AC19  
AA29  
AA27  
AA25  
Y29  
Y26  
Y24  
Y22  
Y20  
W25  
W23  
W21  
V29  
V26  
V24  
U29  
R29  
R26  
D43  
D1  
A40  
A4  
BC9  
BB41  
BB39  
BB34  
BB19  
BB14  
BB11  
296  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
BB6  
BB3  
BA42  
BA4  
AW10  
AV37  
AV17  
AV10  
AV2  
AU34  
AU32  
AU29  
AU26  
AU24  
AU21  
AU20  
AU17  
AU15  
AU13  
AU12  
AU9  
AU6  
AT31  
AT27  
AT26  
AT23  
AT21  
AT18  
AT17  
AT12  
AR43  
AR39  
AR37  
AR32  
AR24  
AR20  
AR15  
AR6  
AR1  
AP38  
AP34  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
297  
Ballout and Package Information  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
AP29  
AP12  
AP10  
AP7  
AP5  
AN42  
AN31  
AN27  
AN26  
AN24  
AN23  
AN21  
AN20  
AN18  
AN17  
AN15  
AN13  
AN4  
AN2  
AM39  
AM37  
AM36  
AM33  
AM9  
AM7  
AM5  
AL43  
AL37  
AL33  
AL32  
AL27  
AL24  
AL23  
AL21  
AL18  
AL15  
AL13  
AL12  
AL10  
AL7  
AL3  
298  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
AL2  
AL1  
AK30  
AK29  
AK26  
AK24  
AJ37  
AJ35  
AJ33  
AJ31  
AJ30  
AJ10  
AJ7  
AH42  
AG39  
AG38  
AG37  
AG36  
AG33  
AG31  
AG30  
AF43  
AF38  
AF36  
AF33  
AF5  
AF3  
AF2  
AF1  
AD42  
AD37  
AD35  
AD33  
AD13  
AD11  
AD9  
AD7  
AC39  
AC38  
AC37  
AC36  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
299  
Ballout and Package Information  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
AC31  
AC23  
AC21  
AC14  
AC10  
AC7  
AC3  
AC2  
AB43  
AB2  
AA36  
AA33  
AA31  
AA23  
AA21  
AA14  
AA12  
AA11  
AA8  
AA3  
Y42  
Y39  
Y37  
Y35  
Y31  
Y14  
Y12  
Y9  
Y6  
Y5  
Y2  
W3  
V43  
V39  
V38  
V37  
V36  
V34  
V14  
V12  
V11  
300  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
V8  
V2  
U38  
U36  
U33  
U31  
U14  
U12  
U9  
U5  
U3  
T42  
T2  
R39  
R37  
R34  
R31  
R30  
R14  
R12  
R9  
R6  
P30  
P29  
P27  
P26  
P24  
P15  
P14  
P3  
N43  
N39  
N36  
N33  
N31  
N29  
N27  
N26  
N24  
N15  
N13  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
301  
Ballout and Package Information  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
N8  
N6  
N2  
M37  
M35  
M21  
M20  
M13  
M10  
M9  
M8  
M5  
M3  
L42  
L31  
L29  
L26  
L24  
L13  
L12  
L2  
K39  
K37  
K34  
K32  
K27  
K20  
K15  
K13  
K12  
K10  
K7  
K6  
K5  
K3  
J43  
J38  
J29  
J24  
J21  
J12  
302  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
J10  
J7  
J5  
J2  
H32  
H27  
H26  
H17  
H12  
G38  
G35  
G32  
G31  
G29  
G27  
G24  
G21  
G20  
G18  
G15  
G13  
G10  
G9  
G7  
G5  
G3  
F42  
F34  
F26  
F18  
F13  
F6  
F2  
E32  
E21  
E20  
E18  
E17  
E13  
E12  
E9  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
303  
Ballout and Package Information  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSSA_DAC  
VSYNC  
VTT  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSSA_DAC  
VSYNC  
VTT  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSS  
VSSA_DAC  
RSV  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
E7  
E4  
E3  
D21  
D20  
D16  
D10  
D5  
D2  
C40  
C22  
C14  
C12  
C7  
C5  
C3  
B38  
B33  
B28  
B22  
B21  
B13  
B11  
B9  
B6  
B4  
A35  
A31  
A26  
A22  
A16  
L17  
A18  
C17  
P23  
N23  
M23  
L23  
K23  
J23  
H23  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
304  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Ballout and Package Information  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
XORTEST  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
XORTEST  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
VTT  
G23  
F27  
F23  
E27  
E26  
E24  
E23  
D25  
D24  
D23  
C26  
C25  
C23  
B26  
B25  
B24  
B23  
A24  
XORTEST  
H20  
§
12.3  
Package  
The (G)MCH package measures 34 mm × 34 mm. The 1202 balls are located in a non-grid  
pattern. The package dimensions are shown in Figure 12-4.  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
305  
Ballout and Package Information  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
307  
Testability  
13 Testability  
In the (G)MCH, testability for Automated Test Equipment (ATE) board level testing has been  
implemented as an XOR chain. An XOR-tree is a chain of XOR gates each with one input pin  
connected to it.  
13.1  
Complimentary Pins  
Table 13-1 contains pins that must remain complimentary while performing XOR testing. The  
first and third column contain the pin and its compliment. The second and fourth column specify  
which chain the associated pins are on.  
Table 13-1. Complimentary Pins to Drive  
Complimentary Pin  
XOR Chain  
Complimentary Pin  
XOR Chain  
SDQS_A0  
SDQS_A1  
SDQS_A2  
SDQS A3  
SDQS_A4  
SDQS_A5  
SDQS_A6  
SDQS_A7  
SDQS_B0  
SDQS_B1  
SDQS_B2  
SDQS_B3  
SDQS_B4  
SDQS_B5  
SDQS_B6  
SDQS_B7  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
Not in XOR Chain  
SDQS_A0#  
SDQS_A1#  
SDQS_A2#  
SDQS_A3#  
SDQS_A4#  
SDQS_A5#  
SDQS_A6#  
SDQS_A7#  
SDQS_B0#  
SDQS_B1#  
SDQS_B2#  
SDQS_B3#  
SDQS_B4#  
SDQS_B5#  
SDQS_B6#  
SDQS_B7#  
4
4
4
4
4
4
4
4
5
5
5
5
5
5
5
5
308  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Testability  
13.2  
XOR Test Mode Initialization  
XOR test mode can be entered by pulling a Reserved ball (ball V30) and XORTEST (ball H20)  
low through the de-assertion of external reset (RSTIN# at ball AJ12). It was intended that no  
clocks should be required to enter this test mode; however, it is recommended that customers use  
the following sequence.  
On power up, hold PWROK (ball AJ9), RSTIN# (ball AJ12), and a Reserved ball (ball V30) low  
and start external clocks. After a few clock cycles, pull PWROK high. After ~3–4 clocks, de-  
assert RSTIN# (pull it high). Release the Reserved ball (ball V30) and XORTEST. No external  
drive. Allow the clocks to run for an additional 32 clocks. Begin testing the XOR chains. Refer to  
Figure 13-1.  
Figure 13-1. XOR Test Mode Initialization Cycles  
32 clocks  
PWROK  
~3-4 Clocks  
XORTEST  
Don’t Care  
Reserved Ball V30  
Don’t Care  
RSTIN#  
Start XOR testing  
XOR_Chain_Tim  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
309  
Testability  
13.3  
XOR Chain Definition  
The (G)MCH chipset has 10 XOR chains. The XOR chain outputs are driven out on the following  
output pins. During fullwidth testing, XOR chain outputs will be visible on both pins.  
Table 13-2. XOR Chain Outputs  
XOR Chain  
Output Pins  
Coordinate Location  
xor_out0  
xor_out1  
xor_out2  
xor_out3  
xor_out4  
xor_out5  
xor_out6  
xor_out7  
xor_out8  
xor_out9  
BSEL2  
ALLZTEST  
XORTEST  
RSV_TP5  
EXP_SLR  
RSV_TP4  
EXP_EN  
RSV_TP6  
BSEL1  
L20  
K18  
H20  
L18  
K21  
L21  
F20  
N21  
H21  
F21  
BSEL0  
310  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Testability  
13.4  
XOR Chains  
Table 13-3 through Table 13-12 show the XOR chains. Section 13.5 has a pin exclusion list.  
Table 13-3. XOR Chain 0 Table 13-3. XOR Chain 0  
Pin Count  
Ball #  
Signal Name  
Pin Count  
Ball #  
Signal Name  
1
M11  
N18  
E15  
F15  
N20  
M18  
J20  
RSV_TP71  
DDC_DATA1  
SDVO_CTRLCLK1  
SDVO_CTRLDATA1  
DDC_CLK1  
ICH_SYNC#  
EXTTS#  
HD42#  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
58  
59  
60  
61  
62  
63  
64  
65  
66  
67  
68  
C32  
D33  
C34  
E34  
B37  
D30  
D38  
E31  
E40  
D34  
C35  
D37  
B34  
A38  
B39  
F32  
H34  
J32  
HD60#  
HD54#  
2
3
HD57#  
4
HDSTBP3#  
HDSTBN3#  
HD63#  
5
6
7
HD53#  
8
J26  
HD48#  
9
M24  
F24  
G26  
K26  
H24  
M27  
L27  
J27  
HD41#  
HD50#  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
HD47#  
HD56#  
HD44#  
HD55#  
HD43#  
HD51#  
HD45#  
HD28#  
HD35#  
HDINV1#  
HD21#  
HD40#  
HDSTBP2#  
HDSTBN2#  
HD46#  
HD29#  
M26  
K24  
C30  
H29  
H31  
K31  
F31  
K29  
M33  
E29  
F29  
B31  
B32  
C39  
A33  
B30  
D32  
C31  
HD23#  
HD25#  
HCPURST#  
HD38#  
C37  
E37  
F35  
G34  
B35  
B40  
J31  
HD24#  
HD17#  
HD32#  
HDSTBP1#  
HDSTBN1#  
HD26#  
HD34#  
HD37#  
HD36#  
HD22#  
HD33#  
HD31#  
HDINV2#  
HD39#  
D39  
J34  
HD19#  
HD27#  
HD58#  
C41  
L32  
J35  
HD20#  
HDINV3#  
HD52#  
HD30#  
HD18#  
HD49#  
F37  
F43  
K41  
G41  
HD16#  
HD62#  
HD15#  
HD61#  
HDSTBP0#  
HD13#  
HD59#  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
311  
Testability  
Table 13-3. XOR Chain 0  
Table 13-4. XOR Chain 1  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
E42  
N42  
M38  
R33  
M34  
N32  
N38  
N35  
F38  
T43  
T40  
U41  
V41  
W41  
W42  
U40  
Y43  
U39  
W40  
R32  
U37  
R36  
U35  
R35  
U34  
R38  
AA41  
Y34  
V35  
V33  
U32  
V42  
V32  
Y36  
Y38  
AA37  
HREQ4#  
HAB14#  
HAB13#  
HAB10#  
HAB8#  
Pin Count  
Ball #  
Signal Name  
69  
70  
71  
72  
73  
74  
75  
76  
77  
78  
79  
80  
L40  
M39  
D41  
K38  
J42  
HD6#  
HD1#  
HREQ1#  
HAB4#  
HAB11#  
HAB16#  
HAB9#  
HAB5#  
K35  
N34  
N37  
P40  
U42  
Y40  
D42  
HAB6#  
HAB12#  
HAB15#  
HDEFER#  
HDBSY#  
HEDRDY#  
HBPRI#  
HPCREQ#  
HRS2#  
HRS0#  
HHIT#  
HDRDY#  
HHITM#  
HADS#  
NOTES:  
1.  
Intel® 82945G/82945GC/82945GZ  
GMCH Only.  
HLOCK#  
HRS1#  
HBNR#  
Table 13-4. XOR Chain 1  
HTRDY#  
HAB17#  
HAB19#  
HAB18#  
HAB26#  
HAB20#  
HAB23#  
HAB21#  
HBREQ0#  
HAB31#  
HADSTB1#  
HAB22#  
HAB24#  
HAB25#  
HAB30#  
HAB27#  
HAB28#  
HAB29#  
Pin Count  
Ball #  
Signal Name  
1
2
G42  
F40  
K42  
G40  
L43  
G39  
P42  
M42  
M41  
P41  
N41  
M40  
K40  
J41  
HD11#  
HD14#  
HD8#  
3
4
HD12#  
HDSTBN0#  
HD9#  
5
6
7
HD2#  
8
HD3#  
9
HD7#  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
HD0#  
HD4#  
HD5#  
HDINV0#  
HD10#  
HREQ3#  
HAB3#  
HREQ2#  
HADSTB0#  
HREQ0#  
HAB7#  
G37  
J39  
K36  
M36  
E41  
J37  
312  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Testability  
Table 13-5. XOR Chain 2  
Table 13-6. XOR Chain 3  
Pin Count  
Ball #  
Signal Name  
Pin Count  
Ball #  
Signal Name  
1
AC40  
AB41  
AA39  
AB42  
AD40  
AE41  
AE42  
AA40  
AD43  
AM42  
AL41  
AF42  
AE40  
AF39  
AH43  
AK42  
AR42  
AP41  
AN40  
AP39  
AM40  
BB40  
AW37  
AY38  
AV38  
AT34  
AV32  
BC33  
BB37  
BA39  
BB35  
AY34  
BA35  
AY28  
BA30  
BB26  
AY32  
AW27  
AY25  
SDM_A7  
SDQ_A62  
SDQ_A58  
SDQ_A63  
SDQ_A56  
SDQ_A61  
SDQ_A60  
SDQ_A59  
SDQ_A57  
SDQ_A53  
SDQ_A48  
SDQ_A55  
SDQ_A51  
SDQ_A50  
SCLK_A5#  
SCLK_A2  
SDQ_A41  
SDQ_A46  
SDQ_A47  
SDM_A5  
1
AD34  
Y32  
SDQ_B57  
SDQ_B58  
SDQ_B62  
SDQ_B59  
SDQ_B56  
SDM_B7  
2
2
3
3
AC33  
AA32  
AC32  
AD39  
AF37  
BB23  
AC35  
AF35  
AL36  
AF32  
AL34  
AJ34  
AD32  
AL31  
BA41  
AW41  
AU40  
AV40  
AM38  
AL35  
AP35  
AR35  
AW42  
AR31  
AU27  
AU31  
AR26  
BA22  
BA17  
AY21  
AY20  
AM26  
AM24  
AP21  
BA14  
BA13  
4
4
5
5
6
6
7
7
SDQ_B61  
SWE_B#  
8
8
9
9
SDQ_B63  
SDQ_B60  
SCLK_B2#  
SDQ_B50  
SDQ_B48  
SDQ_B49  
SDQ_B55  
SDQ_B52  
SCS_B2#  
SCS_B1#  
SODT_B3  
SODT_B1  
SDQ_B46  
SDQ_B43  
SDQ_B40  
SDQ_B44  
SMA_B13  
SDQ_B34  
SDQ_B32  
SDQ_B39  
SCLK_B3#  
SMA_B10  
SMA_B12  
SMA_B3  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
SDQ_A43  
SODT_A3  
SODT_A0  
SCS_A3#  
SDQ_A34  
SDM_A4  
SDQ_A36  
SBS_A0  
SCS_A0#  
SCS_A1#  
SWE_A#  
SBS_A1  
SCS_A2#  
SMA_A8  
SMA_B6  
SDQ_B27  
SDQ_B24  
SDQ_B28  
SCKE_B0  
SCKE_B2  
SMA_A3  
SMA_A12  
SCLK_A0#  
SMA_A11  
SCKE_A1  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
313  
Testability  
Table 13-6. XOR Chain 3  
Table 13-7. XOR Chain 4  
Pin Count  
Ball #  
Signal Name  
Pin Count  
Ball #  
Signal Name  
39  
40  
41  
42  
AT15  
AM17  
AR13  
AV9  
SDQ_B23  
SDQ_B19  
SDQ_B21  
SCLK_B1  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
AR17  
AM20  
BA10  
BA12  
BB12  
BB10  
AY6  
SDQ_A29  
SDQ_A24  
SDQS_A2#  
SDQ_A18  
SDQ_A19  
SDM_A2  
Table 13-7. XOR Chain 4  
SCLK_A4  
SCLK_A1#  
SDQ_A14  
SDQ_A10  
SDQ_A8  
BB5  
Pin Count  
Ball #  
Signal Name  
BC6  
1
AC41  
AG41  
AM41  
AG40  
AL42  
AF41  
AH40  
AK41  
AP40  
AN43  
AU41  
AU42  
AR41  
AY39  
AY37  
AV35  
AU39  
AT32  
AV34  
BA34  
BB31  
BC38  
BC28  
BB27  
BA27  
AY27  
BB25  
AR18  
AM21  
AM18  
SDQS_A7#  
SDQS_A6#  
SDQ_A52  
SDM_A6  
BA7  
2
AW3  
AY2  
3
SDM_A1  
4
BB4  
SDQS_A1#  
SDQS_A0#  
RSV_TP0  
SDQ_A5  
5
SDQ_A49  
SDQ_A54  
SCLK_A5  
SCLK_A2#  
SDQS_A5#  
SDQ_A42  
SDQ_A44  
SDQ_A45  
SDQ_A40  
SODT_A1  
SODT_A2  
SDQS_A4#  
SDQ_A35  
SDQ_A37  
SDQ_A33  
SRAS_A#  
SCLK_A3#  
SMA_A13  
SMA_A6  
AR2  
6
AK17  
AP4  
7
8
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
Table 13-8. XOR Chain 5  
Pin Count  
Ball #  
Signal Name  
1
2
AD38  
AJ36  
AL38  
AG35  
AJ39  
AF34  
AJ32  
AG32  
BA40  
AW40  
AV43  
AY42  
AU38  
AR38  
AM34  
AP37  
AN32  
AM35  
SDQS_B7#  
SCLK_B5#  
SCLK_B2  
SDQ_B54  
SDM_B6  
3
4
5
6
SDQ_B51  
SDQ_B53  
SDQS_B6#  
SCS_B0#  
SCS_B3#  
SODT_B2  
SODT_B0  
SDQ_B45  
SDM_B5  
7
8
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
SMA_A9  
SMA_A5  
SMA_A7  
SCKE_A0  
SDQS_A3#  
SDQ_A27  
SDQ_A25  
SDQ_B47  
SDQ_B41  
SDQ_B42  
SDQS_B5#  
314  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Testability  
Table 13-8. XOR Chain 5  
Table 13-9. XOR Chain 6  
Pin Count  
Ball #  
Signal Name  
Pin Count  
Ball #  
Signal Name  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
42  
43  
44  
45  
46  
47  
48  
AM31  
AR27  
AR29  
AV29  
AM29  
AY24  
BA23  
BB18  
AY17  
BB21  
BA18  
BA19  
AV24  
AM23  
AR21  
AR23  
BB13  
AP15  
AM13  
AM15  
AT13  
AT10  
AV12  
AM11  
AR5  
SDQ_B35  
SDQ_B37  
SDM_B4  
5
BA31  
AY33  
BA32  
AY30  
AW32  
BB32  
BB30  
BA26  
BC24  
BA25  
AV20  
AP20  
AP18  
AT20  
AP17  
AW12  
AY12  
BC11  
AY10  
BB9  
SCLK_A3  
SMA_A10  
SMA_A0  
SMA_A4  
SMA_A1  
SCLK_A0  
SMA_A2  
SBS_A2  
6
7
SDQS_B4#  
SCLK_B0  
SCAS_B#  
SRAS_B#  
SMA_B9  
8
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
SBS_B2  
SCKE_A2  
SCKE_A3  
SDQ_A26  
SDQ_A30  
SDM_A3  
SDQ_A31  
SDQ_A28  
SDQ_A16  
SDQ_A23  
SDQ_A22  
SDQ_A17  
SDQ_A21  
SDQ_A20  
SCLK_A4#  
SCLK_A1  
SDQ_A15  
SDQ_A11  
SDQ_A13  
SDQ_A9  
SDQ_A12  
SDQ_A0  
SDM_A0  
SDQ_A3  
SDQ_A6  
SDQ_A4  
SDQ_A2  
SDQ_A7  
SDQ_A1  
SMA_B1  
SMA_B7  
SMA_B8  
SDQ_B26  
SDQ_B25  
SDQ_B29  
SDQS_B3#  
SCKE_B3  
SDQ_B22  
SDQ_B17  
SDQ_B16  
SDQS_B2#  
SCLK_B4#  
SDQ_B10  
SDQ_B11  
SDQ_B12  
SDQS_B1#  
SDQS_B0#  
SDQ_B4  
BA9  
BA5  
AY5  
AY7  
BB7  
AR9  
AW4  
AY3  
AM6  
AJ11  
AP6  
AV1  
SDQ_B7  
AP3  
AP8  
SDQ_B2  
AR3  
AV4  
AU5  
Table 13-9. XOR Chain 6  
AN1  
AU3  
Pin Count  
Ball #  
Signal Name  
AU2  
1
2
3
4
AU37  
AR34  
AP32  
BA37  
SDQ_A39  
SDQ_A38  
SDQ_A32  
SCAS_A#  
AP2  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
315  
Testability  
Table 13-11. XOR Chain 8  
Table 13-10. XOR Chain 7  
Pin Count  
Ball #  
Signal Name  
Pin Count  
Ball #  
Signal Name  
1
F12  
C13  
D12  
B12  
H13  
B10  
F10  
C9  
EXP_RXN0  
EXP_TXN0  
EXP_RXN1  
EXP_TXN1  
EXP_RXN2  
EXP_TXN2  
EXP_RXN3  
EXP_TXN3  
EXP_RXN4  
EXP_TXN4  
EXP_RXN5  
EXP_TXN5  
EXP_RXN6  
EXP_TXN6  
EXP_RXN7  
EXP_TXN7  
EXP_RXN8  
EXP_TXN8  
EXP_RXN9  
EXP_TXN9  
EXP_RXN10  
EXP_TXN10  
EXP_RXN11  
EXP_TXN11  
EXP_RXN12  
EXP_TXN12  
EXP_RXN13  
EXP_TXN13  
EXP_RXN14  
EXP_TXN14  
EXP_RXN15  
EXP_TXN15  
EXP_RXP0  
EXP_TXP0  
EXP_RXP1  
EXP_TXP1  
EXP_RXP2  
EXP_TXP2  
EXP_RXP3  
1
AN29  
AP31  
AP27  
AM27  
AP26  
AW23  
AY23  
BC20  
BB22  
BB17  
BA21  
AY19  
AT24  
AP24  
AP23  
AY16  
AV15  
AP13  
AN12  
AW9  
AU10  
AU7  
SDQ_B33  
SDQ_B38  
SDQ_B36  
SCLK_B0#  
SCLK_B3  
SBS_B0  
2
2
3
3
4
4
5
5
6
6
7
7
SBS_B1  
8
8
SMA_B4  
SMA_B0  
SMA_B11  
SMA_B2  
SMA_B5  
SDQ_B31  
SDQ_B30  
SDM_B3  
SCKE_B1  
SDQ_B18  
SDM_B2  
SDQ_B20  
SCLK_B1#  
SCLK_B4  
SDQ_B8  
SDQ_B15  
SDQ_B14  
SDM_B1  
SDQ_B13  
SDQ_B9  
SDM_B0  
SDQ_B0  
SDQ_B5  
SDQ_B6  
SDQ_B3  
SDQ_B1  
9
H10  
B7  
9
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
21  
22  
23  
24  
25  
26  
27  
28  
29  
30  
31  
32  
33  
F9  
D6  
D3  
B5  
J6  
F1  
K8  
J1  
G4  
K4  
M7  
M4  
L1  
AR10  
AR12  
AW7  
AR7  
N1  
U10  
T1  
R7  
AV6  
U4  
AL11  
AL6  
N3  
V1  
AL9  
Y11  
W4  
G12  
D14  
D11  
A13  
J13  
A11  
E10  
AM10  
AP9  
AL8  
316  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
Testability  
Table 13-11. XOR Chain 8  
Table 13-12. XOR Chain 9  
Pin Count  
Ball #  
Signal Name  
Pin Count  
Ball #  
Signal Name  
40  
41  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
53  
54  
55  
56  
57  
58  
59  
60  
61  
62  
63  
64  
C10  
J9  
EXP_TXP3  
EXP_RXP4  
EXP_TXP4  
EXP_RXP5  
EXP_TXP5  
EXP_RXP6  
EXP_TXP6  
EXP_RXP7  
EXP_TXP7  
EXP_RXP8  
EXP_TXP8  
EXP_RXP9  
EXP_TXP9  
EXP_RXP10  
EXP_TXP10  
EXP_RXP11  
EXP_TXP11  
EXP_RXP12  
EXP_TXP12  
EXP_RXP13  
EXP_TXP13  
EXP_RXP14  
EXP_TXP14  
EXP_RXP15  
EXP_TXP15  
1
2
Y8  
Y7  
DMI_RXN0  
DMI_RXP0  
DMI_TXN0  
DMI_TXP0  
DMI_RXN1  
DMI_RXP1  
DMI_TXN1  
DMI_TXP1  
DMI_RXN2  
DMI_RXP2  
DMI_TXN2  
DMI_TXP2  
DMI_RXN3  
DMI_RXP3  
DMI_TXN3  
DMI_TXP3  
A9  
F7  
3
Y1  
D7  
C4  
A6  
G6  
E2  
K9  
G2  
F4  
4
W2  
5
AA10  
AA9  
AB1  
AA2  
AA7  
AA6  
AA4  
Y4  
6
7
8
9
10  
11  
12  
13  
14  
15  
16  
J3  
M6  
L4  
AC8  
AC9  
AC4  
AB3  
K2  
M2  
U11  
P2  
R8  
T4  
P4  
U2  
Y10  
V3  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  
317  
Testability  
13.5  
PADs Excluded from XOR Mode(s)  
A large number of pads do not support XOR testing. The majority of the pads that fall into this  
category are analog related pins (see Table 13-13).  
Table 13-13. XOR Pad Exclusion List  
PCI Express*  
GCLKN  
FSB  
HCLKN  
SM  
SRCOMP1  
Misc  
DREFCLKN  
DREFCLKP  
BLUE  
GCLKP  
HCLKP  
SRCOMP0  
EXP_COMPO  
EXP_COMPI  
HRCOMP  
HSCOMP  
HVREF  
SMVREF1  
SMVREF0  
BLUE#  
SOCOMP1  
GREEN  
GREEN#  
RED  
HSWING  
SOCOMP0  
SM_SLEWOUT1  
SM_SLEWOUT0  
SM_SLEWIN1  
SM_SLEWIN0  
RED#  
RSTIN#  
HSYNC  
VSYNC  
REFSET  
318  
Intel® 82945G/82945GZ GMCH and 82945P/82945PL MCH Datasheet  

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