
System Address Space
A–17
PCI Sparse Memory Space
Figure 1–8 shows dense-space address generation.
Figure 1–8 Dense-Space Address Generation
The following list describes address generation in dense space:
•
addr_h<31:5> value is sent directly out on ad<31:5>.
•
addr_h<4:2> is not sent out by the 21164 and instead is inferred from the
int4_valid<3:0>.
•
ad<4:3> is a copy of addr_h<4:3>.
•
ad<2> differs for read and write transactions as follows:
–
For a read transaction, ad<2> is zero (that is, the minimum read transaction
resolution in noncached space is a quadword).
–
For a write transaction, ad<2> equals addr_h<2>.
1.7 PCI Sparse Memory Space
The system provides three regions of contiguous 21164 address space that maps
to PCI sparse memory space. The total 21164 range is from 80.0000.0000 to
85.7FFF.FFFF.
LJ04264A.AI4
1
1
21164 Address
<31:5>
PCI Dense
Memory
Address
0 0
21164
int4_valid
0 0
31
05 04
02 01 00
34 33 32 31
05 04
02 01 00
39 38
35
1 0