5. Board Resources
SPI-8451-LLVA, SPI-8452-LLVA, SPI-8451-LVA 39
5. Board Resources

System address map

The GMCH memory map includes a number of programmable ranges. All of these ranges must be
unique and non-overlapping. There are no hardware interlocks to prevent problems in the case of
overlapping ranges. Accesses to overlapped ranges may produce indeterminate results.
Table 5.1. Compatibility Area
Address Description
0 - 640KB DOS area
640 - 768KB Video Buffer area
768 - 896KB Expansion Area
896 - 960KB Extended System BIOS Area
960 - 1MB System BIOS Area
Table 5.2. Memory Segment
Memory Segments Comments
00000h - 9FFFFh 0 - 640K DOS Region
A0000h - BFFFFh Video Buffer
B0000h - B7FFFh Monochrome Adapter range
C0000h - CBFFFh Video BIOS
CC000h - CFFFFh Reserved
D0000h - DFFFFh Expansion Area
E0000h - EFFFFh Extended System BIOS Area
F0000 - FFFFFh System BIOS Area
100000h - 7FFFFFFFh Extended Memory Area
00100000 to Top of Main Memory Main DRAM Address Range
Top of Main Memory Extended SMRAM Address Range
Top of Main Memory To 4GB PCI Memory Address Range
FEC0000h - FECFFFFFh,
FEE00000h - FEEFFFFFh APIC configuration space
FFE0000h - FFFFFFFFh High BIOS Area