Intel 460GX - Manual (Page 82)

System Address Map
4-2 Intel® 460GX Chipset Software Developer’s Manual
4.1.1.4 System Firmware
The 64 KB region from F_0000h to F_FFFFh is treated as a single block. Read/Write attribute
enables defined in the MAR registers may be used to direct accesses to the compatibility PCI bus
or main memory. At power-on, this area is mapped by default to the PCI compatibility bus.
Figure 4-1. System Memory Address Space
0
A_0000
C_0000
F_0000
Compatibility
Area
Extended
Memory
10_0000
16 MB
FEC0_0000
FF00_0000
FE00_0000
Processor
12 MB
Chipset
4 MB
1 MB
15 MB
(4 GB-16MB)
(16 TB-4GB)
System
32
Firmware,
Processor &
Chipset
Memory
Specific
System
1_0000_0000
Memory
FFF_FFFF_FFFF
MB
Areas are not
drawn to scale.
Specific
Specific
FFFF_FFFF
PCI Gaps
n x 32M
Memory
Extended
High
Medium
Extended
memory
Low
DOS
System
192K
C, D, and E
Segments
VGA
Memory
Region
FE00_0000 -
(n x 32M)
High
System
512K-640K
64K
640K
128K
Firmware
Firmware