Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL
12-24
Figure 12-16. Demand Data-transfer Mode with Chaining Buffer-transfer Mode
No new transfer information, so channel
becomes idle.
A2336-02
Yes
Was the
channel set up
for a new
process?
Yes
No
DMA is
programmed
with the new
addresses and 
byte count.
Yes
Write new
requester
and target
addresses
and a new
byte count.
Is there
a new process
to set up?
Yes
No DREQ

n

active?
Yes
No
No
DREQ

n

active?
No
DMA channel
relinquishes
bus control.
Byte
count = FFFFFFH
or EOP#
active?
DMA channel relinquishes bus control.
DMA transfers one byte or word of data
and decrements the byte count.
DMA gains bus control.
After initialization, the DAM channel is
programmed with the requester and target
addresses and a byte count.