4.28 PC Card 16-Bit I/F Legacy-Mode Base-Address Register
The PCI6x21/PCI6x11 controller supports the index/data scheme of accessing the ExCA registers, which is mapped
by this register. An address written to this register is the address for the index register and the address+1 is the data
address. Using this access method, applications requiring index/data ExCA access can be supported. The base
address can be mapped anywhere in 32-bit I/O space on a word boundary; hence, bit 0 is read-only, returning 1 when
read. As specified in the PCI to PCMCIA CardBus Bridge Register Description specification, this register is shared
by functions 0 and 1. See the ExCA register set description in Section 5 for register offsets. All bits in this register
are reset by GRST only.
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Name
Type
Default
PC Card 16-bit I/F legacy-mode base-address
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
Type
Default
PC Card 16-bit I/F legacy-mode base-address
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
RW
0
R
1
Register:
Offset:
Type:
PC Card 16-bit I/F legacy-mode base-address
44h (Functions 0, 1)
Read-only, Read/Write
Default:
0000 0001h
4−17