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Figure 1212. block data-transfer mode with autoin – Intel 386 User Manual

Page 355

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Intel386™ EX EMBEDDED MICROPROCESSOR USER’S MANUAL

12-20

Figure 12-12. Block Data-transfer Mode with Autoinitialize Buffer-transfer Mode

A2333-02

Yes

No

DREQ

n

active?

Yes

No

Byte

count = FFFFFFH

or EOP#

active?

DMA channel is reprogrammed with the

original addresses and byte count.

DMA channel relinquishes bus control.

DMA transfers one byte or word of data

and decrements the byte count

DMA gains bus control.

After initiallization, the DMA channel is

programmed with the requester and target

addresses and a byte count.