System Address Map
R
Intel
®
82925X/82925XE MCH Datasheet
159
Figure 9-2. Microsoft MS-DOS* Legacy Address Range
Expansion Area
128KB (16KBx8)
000C_0000h
000D_FFFFh
896KB
Extended System BIOS (Lower)
64KB (16KBx4)
000E_0000h
000E_FFFFh
960KB
Legacy Video Area
(SMM Memory)
128KB
000A_0000h
000B_FFFFh
768KB
DOS Area
0000_0000h
0009_FFFFh
640KB
System BIOS (Upper)
64KB
000F_0000h
000F_FFFFh
1MB
9.1.1
DOS Range (0h – 9_FFFFh)
The DOS area is 640 KB (0000_0000h – 0009_FFFFh) in size and is always mapped to the main
memory controlled by the MCH.
9.1.2
Legacy Video Area (A_0000h–B_FFFFh)
The legacy 128-KB VGA memory range, frame buffer, (000A_0000h – 000B_FFFFh) can be
mapped to PCI Express and/or to the DMI. The appropriate mapping is programmable. Based on
the programming, priority for VGA mapping is constant. The MCH always decodes internally
mapped devices first. The MCH always positively decodes internally mapped devices, namely the
PCI Express. Subsequent decoding of regions mapped to PCI Express or the DMI depends on the
programming. This region is also the default for SMM space.
Содержание 82925X
Страница 78: ...Host Bridge DRAM Controller Registers D0 F0 R 78 Intel 82925X 82925XE MCH Datasheet...
Страница 98: ...EPBAR Registers Egress Port Register Summary R 98 Intel 82925X 82925XE MCH Datasheet...
Страница 108: ...DMIBAR Registers Direct Media Interface DMI RCRB R 108 Intel 82925X 82925XE MCH Datasheet...
Страница 156: ...Host PCI Express Graphics Bridge Registers D1 F0 R 156 Intel 82925X 82925XE MCH Datasheet...
Страница 172: ...System Address Map R 172 Intel 82925X 82925XE MCH Datasheet...
Страница 192: ...Electrical Characteristics R 192 Intel 82925X 82925XE MCH Datasheet...
Страница 220: ...Ballout and Package Information R 220 Intel 82925X 82925XE MCH Datasheet Figure 12 3 MCH Package Dimensions MCH...