Processor Users Manual

8-20 MPC8260 PowerQUICC II UserÕs Manual MOTOROLA
Part III. The Hardware Interface
8.4.3.8 Extended Transfer Mode
The MPC8260 supports an extended transfer mode that improves bus performance. This
should not be confused with the extended bus protocol used to support direct-store
operations supported in some earlier PowerPC processors. The MPC8260 can generate 5-,
6-, 7-, 16-, or 24-byte extended transfers. These transactions are compatible with the 60x
Table 8-10. Address and Size State Calculations
Size State Address State [0Ð4] Port Size Next Size State Next Address State [0Ð4]
Byte xxxxx x Stop
2-Byte xxxx0 Byte Byte xxxx1
x x 0 0 1 Byte x x 0 1 0
x x 1 0 1 Byte x x 1 1 0
x x x 0 1 Half Byte x x x 1 0
xxxx0 Stop
3-Byte x x 0 0 0 Byte 2-Byte x x 0 0 1
x x 0 0 1 2-Byte x x 0 1 0
x x 1 0 0 2-Byte x x 1 0 1
x x 1 0 1 2-Byte x x 1 1 0
x x 0 0 0 Half Byte x x 0 1 0
x x 0 0 1 2-Byte x x 0 1 0
x x 1 0 0 Byte x x 1 1 0
x x 1 0 1 2-Byte x x 1 1 0
xxxxx Word Stop
4-Byte x x x 0 0 Byte 3-Byte x x x 0 1
x x x 0 0 Half 2-Byte x x x 1 0
xxxxx Word Stop
5-Byte x x 0 1 1 Byte 4-Byte x x 1 0 0
6-Byte x x 0 1 0 Byte 5-Byte x x 0 1 1
x x 0 1 0 Half 4-Byte x x 1 0 0
7-Byte x x 0 0 1 Byte 6-Byte x x 0 1 0
8-Byte x x 0 0 0 Byte 7-Byte x x 0 0 1
x x 0 0 0 Half 6-Byte x x 0 1 0
x x 0 0 0 Word 4-Byte x x 1 0 0
x x 0 0 0 Double Stop