Bits 31 to 24—Memory Space Base Address (MBR31 to 24): Sets the base address for the PCI
memory space in PIO transfers. (Initial value is undefined.)
Bits 23 to 1—Reserved: These bits always return 0 when read. Always write 0 to these bits when
writing.
Bit 0—Lock Transfer (LOCK): Specifies the locking of the memory space during PIO transfer.
Bit 0: LOCK
0
1
22.2.34 I/O Space Base Register (PCIIOBR)
Bit:
31
IOBR31
Initial value:
0
PCI-R/W:
—
PP Bus-R/W:
R/W
Bit:
23
IOBR23
Initial value:
0
PCI-R/W:
—
PP Bus-R/W:
R/W
Bit:
15
—
Initial value:
0
PCI-R/W:
—
PP Bus-R/W:
R
Bit:
7
—
Initial value:
0
PCI-R/W:
—
PP Bus-R/W:
R
Rev. 3.0, 04/02, page 868 of 1064
Description
Not locked
Locked
30
29
IOBR30
IOBR29
0
0
—
—
R/W
R/W
22
21
IOBR22
IOBR21
0
0
—
—
R/W
R/W
14
13
—
—
0
0
—
—
R
R
6
5
—
—
0
0
—
—
R
R
28
27
IOBR28
IOBR27
0
0
—
—
R/W
R/W
20
19
IOBR20
IOBR19
0
0
—
—
R/W
R/W
12
11
—
—
0
0
—
—
R
R
4
3
—
—
0
0
—
—
R
R
(Initial value)
26
25
IOBR26
IOBR25
IOBR24
0
0
—
—
R/W
R/W
18
17
IOBR18
—
0
0
—
—
R/W
R
10
9
—
—
0
0
—
—
R
R
2
1
—
—
0
0
—
—
R
R
24
0
—
R/W
16
—
0
—
R
8
—
0
—
R
0
LOCK
0
—
R/W