Figure 3-6. System Memorym - Compaq Deskpro EXS Technical Reference Manual

The memory controller and RDRAM are configured by BIOS during POST. Refer to Chapter 8 for
the configuration procedure performed by BIOS.
Figure 3-6 shows the system memory map.
Host,
PCI, AGP Area
Host, PCI,
ISA Area
DOS Compatibility
Area
NOTE: All locations in memory are cacheable. Base memory is always mapped to DRAM. The next 128 KB
fixed memory area can, through the MCH, be mapped to DRAM or to PCI space. Graphics RAM area is
mapped to PCI or AGP locations.
Figure 3–6. System Memory Map
FFFF FFFFh
High BIOS Area
(2 MB)
FFE0 0000h
FFDF FFFFh
PCI Memory
(18 MB)
FEC1 0000h
FEC0 FFFFh
APIC Config. Space
(64 KB)
FEC0 0000h
FEBF FFFFh
PCI Memory
Expansion
(3060 MB)
2000 0000h
1FFF FFFFh
Host/PCI Memory
Expansion
(496 MB)
0100 0000h
00FF FFFFh
Extended Memory
(15 MB)
0010 0000h
000F FFFFh
System BIOS Area
(64 KB)
000F 0000h
000E FFFFh
Extended BIOS
Area
000E 0000h
000D FFFFh (64 KB)
Option ROM
(128 KB)
000C 0000h
000B FFFFh
Graphics/SMRAM
RAM (128 KB)
000A 0000h
0009 FFFFh
Fixed Mem. Area
(128 KB)
0008 0000h
0007 FFFFh
Base Memory
(512 KB)
0000 0000h
Compaq Deskpro EXS and Workstation 300 Personal Computers
Featuring the Intel Pentium 4 Processor
First Edition - December 2000
Technical Reference Guide
4 GB
512 MB
16 MB
1 MB
640 KB
512 KB
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