User`s guide

Note
The window base addresses must be on naturally aligned address
boundaries, depending on the size of the window.
Figure 4–4 PCI Target Window Compare Scheme
LJ-03955.AI
31
nn 20 19 13 12 00
31 nn 20
Offset
Hit
XXX
Compare
Peripheral Page NumberPCI Address
PCI Base
Register
31 nn
-1
-1
-1 20
111 (Determines ) n 0000000
PCI Mask
Register
When an address match occurs with a PCI target window, the 21071-DA
translates the 32-bit PCI address ad<31:0> to a 34-bit processor byte address
(actually a 29-bit hexword address). The translated address is generated in
one of two ways as determined by the scatter-gather enable (SGEN) bit of the
PCI base register of the associated window.
System Address Mapping 4–21