12-23
DMA CONTROLLER
Figure 12-15. Demand Data-transfer Mode with Autoinitialize Buffer-transfer Mode
After initialization, the DMA channel is
programmed with the requester and target
addresses and a byte count.
DMA gains bus control.
DMA transfers one byte or word of data
and decrements the byte count.
DMA channel is reprogrammed with the
original addresses and byte count.
A2339-02
Yes
No
DREQ

n

active?
Yes
No
DMA channel
relinquishes
bus control.
DREQ

n

active?
Yes
No
Byte
count = FFFFFFH
or EOP#
active?
DMA channel relinquishes bus control.