CHAPTER 4 DMA
Figure 4.5-4 Transfer of the last byte of a channel set to word transfer and BAP decrement
H
L
■ Word transfers with incrementing IOA and decrementing BAP
When IOA is set to be incremented and BAP is set to be decremented, the order of the transmitted words is
reversed, but not the order of the bytes inside a word. Figure 4.5-5 exemplifies the memory contents after the
completion of two transfers.
Figure 4.5-5 Word transfer with incrementing IOA and decrementing BAP
H
High byte
Transfer 1
High byte
Transfer 0
L
138
22
H
00BCDE
H
Low byte
Transfer 1
00BCE0
H
Low byte
Transfer 0
00BCDE
H
MB96300 Super Series Hardware Manual
High byte
Low byte
Transfer 0
Transfer 0
High byte
Low byte
Transfer n
Transfer n
22
H
High byte
Transfer 0
Low byte
High byte
Transfer 0
Transfer 1
Low byte
Transfer 1
01CCAA
H
01CCA8
H
01
CC
AB
BAP
BC
DE
IOA
01CCAA
H
01CCA8
H
01
CC
AB
BAP
BC
DE
IOA