CHAPTER 7 DMAC
Preliminary User’s Manual A14874EJ3V0UM
179
Figure 7-29. DMA Transfer Forcible Termination Example (2/2)
(b) The transfer is forcibly terminated during block transfer using DMA channel 1 and a transfer with
another condition is executed
DMA1
CPU
CPU
CPU
CPU DMA1
CPU
CPU
CPU
CPU DMA1
DMA1
DMA1
DMA1 DMA1
DMARQ1
(Input)
DMA1 DMA1
DMA channel 1
terminal count
DMA channel 1 transfer is forcibly
terminated and the bus is released
EN1 bit = 1
TC1 bit = 0
EN1 bit
→
0
TC1 bit
→
1
DSA1, DDA1, DBC1,
DADC1, DCHC1
Set register
CPU
DSA1, DDA1,
DBC1
Set register
DCHC1
(INIT1 bit = 1)
Set register
DADC1,
DCHC1
Set register
EN1 bit
→
0
TC1 bit = 0
EN1 bit
→
1
TC1 bit = 0
Remark
Since the DSAn, DDAn, and DBCn registers are buffer registers with an FIFO configuration, the
values are retained even after a forcible termination. Also, the next transfer condition can be set
even during a DMA transfer. However, a setting in the DADCn register is ignored (See
7.6 Next
Address Setting
Function
).