
A–44
System Address Space
Suggested Use of a PCI Window
1.16 Suggested Use of a PCI Window
Figure 1–22 shows the PCI window assignment after power is turned on (configured
by firmware), and Table A–15 lists the details. PCI window 0 was chosen for the
8MB to 16MB EISA region because this window incorporates the mem_cs_l logic.
PCI window 3 was not used as it incorporates the DAC cycle logic. PCI window 1
was chosen arbitrarily for the 1GB, direct-mapped region, and PCI window 2 is not
assigned.
Figure 1–22 Default PCI Window Allocation
21164
Memory Space
PCI
Memory Space
4GB
4GB
2GB
1GB
1GB
Scatter-Gather
Window 0
Direct-Mapped
Window 1
16MB
8MB
0MB
0
1GB
1GB
8MB
LJ-04278.AI4