AN2168 Freescale Semiconductor / Motorola, AN2168 Datasheet - Page 20

Manufacturer Part Number

AN2168

Description

ColdFire Microprocessor DMA Controller Application Note

Manufacturer

Freescale Semiconductor / Motorola

Datasheet

1.AN2168.pdf (28 pages)

Application Note

Generating a

DACK at the End

of a DMA Cycle

NOTE:

At times, it is useful to have a DMA acknowledge that indicates when the

entire DMA transfer is complete, for instance, the BCR decrements to

zero. The MCF5307 (revision A and higher) and the MCF5407 have a

feature that allows for this. The DMA acknowledge type bit (DCR[AT])

can be programmed so that the DACK will assert for every transfer

(default) or so that DACK is asserted only during the final read and/or

write of the entire DMA transfer.

The AT bit is only available on the MCF5307 when the BCR24BIT in the

bus master park register (MPARK) is set.

MOTOROLA

AN2168