5.23 ExCA Memory Windows 0−4 Page Registers
The upper 8 bits of a 4-byte PCI memory address are compared to the contents of this register when decoding
addresses for 16-bit memory windows. Each window has its own page register, all of which default to 00h. By
programming this register to a nonzero value, host software can locate 16-bit memory windows in any one of 256
16-Mbyte regions in the 4-gigabyte PCI address space. These registers are only accessible when the ExCA registers
are memory-mapped, that is, these registers may not be accessed using the index/data I/O scheme.
Bit
7
6
5
4
3
2
1
0
Name
Type
Default
ExCA memory windows 0−4 page
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
R
0
Register:
Offset:
Type:
ExCA memory windows 0−4 page
CardBus Socket Address + 840h, 841h, 842h, 843h, 844h
Read/Write
00h
Default:
5−24