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PowerPC Addressing and Alignment

In general, PCI expansion cards that run code directly on PowerPC processors in Power Macintosh computers must use 32-bit mode even when the processor supports 64-bit mode. PCI cards must observe the access sizes and byte alignments shown in Table 4-1.

Table 4-1 PowerPC processor addressing

Open Firmware Address type

Access size (bits)

Alignment
(bytes)
a-addr 32 4
q-addr 32 4
w-addr 16 2
© 1999 Apple Computer, Inc. – (Last Updated 26 March 99)