B-6 One-Byte Transfer To Pci Memory Space—Little-Endian Mode - Motorola MPC8240 User Manual

0
xx
AD[3–0]
Figure B-6. One-Byte Transfer to PCI Memory Space—Little-Endian Mode
Core
Processor
A28–A31 0 0 1 0
Munge address
XOR with 111
PA[28–31]
0 1 0 1
1 2 3 4 5
xx xx xx xx D5
CDU
Unmunges address
Swaps byte lanes
Runs PCI memory transaction
During address phase
0 0 0 0
(AD[1–0] = 0b00 for memory space access)
3 2 1
xx D5 xx xx
D5
PCI Memory Space
Appendix B. Bit and Byte Ordering
Byte lanes
6 7
Internal peripheral logic data bus
xx xx
PCI byte lanes (C/BE2 asserted)
0
PCI data bus (AD[31–0] during data phase)
0x00
0x08
Little-Endian Mode
B-9