
System Address Space
A–13
21164 Byte/Word PCI Space
Figure 1–7 Byte/Word PCI Space
Operations are the same for the four regions. The 21164 will issue a single byte/word
read or write transaction for PCI byte and word instructions. The 21164 will not
pack longword load instructions. The 21164 can pack up to eight longword store
instructions for a single 32-byte block into one transaction. Up to four quadword
instructions can also be packed to the same 32-byte block. Byte/word support is
enabled when 21164 IPR register ICSR<17> equals 1 and when 21174 CSR register
PYXIS_CTRL1<0> also equals 1.
31
2
1
0
LJ-05399.AI4
36
37
35 34 33 32
38
39
PCI Memory Address <31:2>
0
1
X
0
0
1 Size
0 0
PCI Memory Space — 4GB
31
0
36
37
35 34 33 32
38
39
PCI I/O Address
1
1
X
0
0
1 Size
PCI I/O Space — 4GB
31
2
1
0
36
37
35 34 33 32
38
39
PCI Configuration Address <31:2>
0
1
X
1
0
1 Size
0 0
PCI Type 0 Configuration Space — 4GB
31
2
1
0
36
37
35 34 33 32
38
39
PCI Configuration Address <31:2>
1
1
X
1
0
1 Size
0 1
PCI Type 1 Configuration Space — 4GB