System Address Map
R
158
Intel
®
82925X/82925XE MCH Datasheet
The rules for the above programmable ranges are:
•
ALL of these ranges MUST be unique and NON-OVERLAPPING. It is the BIOS or system
designer’s responsibility to limit memory population so that adequate PCI, PCI Express, High
BIOS, PCI Express Memory Mapped space, and APIC memory space can be allocated.
•
In the case of overlapping ranges with memory, the memory decode will be given priority.
•
There are NO Hardware Interlocks to prevent problems in the case of overlapping ranges.
•
Accesses to overlapped ranges may produce indeterminate results.
•
The only peer-to-peer cycles allowed below the top of memory (register TOLUD) are DMI to
PCI Express VGA range writes.
Figure 9-1 shows the system memory address map in a simplified form.
Figure 9-1. System Address Ranges
PCI Memory
Address Range
(Subtractively
decoded to DMI)
Main Memory
Address Range
Legacy Address
Range
0
1 MB
TOLUD
4 GB
Device 0
Bars
(EPBAR,
MCHBAR,
PCIEXBAR,
DMIBAR)
Device 1
Bars
(MBASE1/
MLIMIT1,
PMBASE1/
PMLIMIT1)
Independently Programmable
Non-Overlapping Windows
Sys_Address_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
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...