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

 

 

 

ExCA memory windows 0−4 page

 

 

 

 

 

 

 

 

 

 

 

 

 

Type

RW

RW

RW

 

RW

RW

RW

RW

R

 

 

 

 

 

 

 

 

 

 

Default

0

0

0

 

0

0

0

0

0

Register: ExCA memory windows 0−4 page

Offset: CardBus Socket Address + 840h, 841h, 842h, 843h, 844h

Type: Read/Write

Default: 00h

5−24

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Texas Instruments PCI7411, PCI7611, PCI7621 manual ExCA Memory Windows 0−4 Page Registers, Register ExCA memory windows 0−4