CHAPTER 7 DMAC
Preliminary User’s Manual A14874EJ3V0UM
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Figure 7-14 shows a single transfer mode example in which a lower priority DMA transfer request is generated
within one clock after the end of a single transfer. DMA channels 0, 3 are used for a single transfer. When two DMA
transfer request signals are activated at the same time, the two DMA transfers are performed alternately.
Figure 7-14. Single Transfer Example 3
CPU
CPU
DMA3
DMA0 CPU
DMA0
CPU
CPU
CPU
CPU
DMA0
CPU DMA0
DMA3
CPU
CPU DMA0
DMARQ3
(Input)
CPU DMA0
DMA channel 0
terminal count
Note
Note
Note
Note
DMARQ0
(Input)
DMA channel 3
terminal count
Note
Note
Note
Note
The bus is always released.
Figure 7-15 shows a single transfer mode example in which two or more lower priority DMA transfer requests are
generated within one clock after the end of a single transfer. DMA channels 0, 2, and 3 are used for a single transfer.
When three or more DMA transfer request signals are activated at the same time, always the two highest priority
DMA transfers are performed alternately.
Figure 7-15. Single Transfer Example 4
DMA2 CPU
DMA3
CPU
CPU DMA3 CPU
CPU
DMA2
DMA0 CPU
DMARQ3
(Input)
DMA0
Note
Note
Note
DMARQ2
(Input)
Note
Note
DMARQ0
(Input)
DMA2 CPU
DMA channel 0
terminal count
Note
DMA3 CPU DMA2 CPU
CPU
DMA3
DMA channel 3
terminal count
Note
CPU
CPU
Note
DMA channel 2
terminal count
Note
Note
The bus is always released.