CHAPTER 7 DMAC
Preliminary User’s Manual A14874EJ3V0UM
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Figures 7-20 and 7-21 show line transfer mode examples in which a lower priority DMA transfer request is
generated within one clock after the end of a line transfer. When two DMA transfer request signals are activated at
the same time, the two DMA transfers are performed alternately.
DMA channels 0 and 3 in Figure 7-20 are used for line transfer.
Figure 7-20. Line Transfer Example 3
DMA3 CPU
DMA0
CPU
DMA0 DMA0 DMA0
DMA3
CPU
DMA3 DMA3
DMARQ3
(Input)
DMA0
Note
Note
DMARQ0
(Input)
DMA0 DMA0
DMA channel 0
terminal count
CPU DMA3 DMA3 DMA3
CPU
DMA3
DMA channel 3
terminal count
Note
CPU
DMA0
Note
The bus is always released.
DMA channel 0 in Figure 7-21 is used for a single transfer, and channel 3 is used for a line transfer.
Figure 7-21. Line Transfer Example 4
DMA3 CPU
CPU
CPU
DMA0 CPU DMA0
DMA3
CPU
DMA3 DMA3
DMARQ3
(Input)
DMA0
Note
Note
DMARQ0
(Input)
DMA3 DMA3
DMA channel 3
terminal count
DMA3 DMA3 CPU DMA0
CPU
CPU
DMA channel 0
terminal count
CPU
Note
Note
Note
Note
The bus is always released.