AN2168 Freescale Semiconductor / Motorola, AN2168 Datasheet - Page 21

• Manufacturer Part Number: AN2168
• Description: ColdFire Microprocessor DMA Controller Application Note
• Manufacturer: Freescale Semiconductor / Motorola

AN2168
MOTOROLA
NEGATE EXTERNAL
FOR AT LEAST ONE
OF EXTERNAL BUS.
FOR MASTERSHIP
THEN REASSERT
BUS REQUEST
REQUEST
CLOCK.
MASTERSHIP OF
WAIT FOR NEXT
THEN REQUEST
EXTERNAL BUS
REQUEST.
Figure 9. Dual Address Mode DMA Flowchart
Y
DMA READ PHASE BUS CYCLE(S)
Y
MASTERSHIP OF EXTERNAL BUS
RECEIVED, AND DMA GRANTED
DMA PROGRAMMED, REQUEST
CYCLE(S) FROM DESTINATION
BCR = MULTIPLE OF BWC?
(INTERNAL OR EXTERNAL)
FROM SOURCE ADDRESS
DMA WRITE PHASE BUS
BCR DECREMENTED
CYCLE STEAL?
SINC = 1?
ADDRESS
DINC = 1?
BCR = 0?
ERROR?
ERROR?
N
N
N
N
N
N
N
Y
Y
Y
Y
Y
BUS ERROR ON SOURCE (BES)
BUS ERROR ON DESTINATION
AND DONE BITS SET IN DSR
(BED) AND DONE BITS
SET DONE BIT IN DSR
SAR INCREMENTED
DAR INCREMENTED
SET IN DSR
DACK Generation
Application Note
21