
RX610 Group
12. DMA Controller (DMAC)
R01UH0032EJ0120 Rev.1.20
Page 328 of 1006
Feb 20, 2013
12.3.6
Suspending, Restarting, and Canceling DMA Transfer
(1) Suspending DMA transfer
DMA transfer by operand transfer can be suspended by clearing the DMST (DMAC stop) bit in DMSCNT or the DEN
bit in DMCRE for DMACm to 0 (disabling DMA transfer on that channel).
Suspension applies to all channels when the DMST bit is 0 or the corresponding channel n when DEN bit is 0, and
becomes effective on completion of the transfer for the operand for which transfer was in progress.
Nonstop DMA transfer is not suspended even when the DMST or DEN bit is cleared to 0; instead, DMA transfer
continues until it is completed.
In advance of transitions of the DMAC to the module-stop state or of the overall device to all-module clock stop mode,
software standby mode, or deep software standby mode, clear the DMST bit to 0 (stopping the DMAC).
(2) Restarting DMA transfer
Suspended DMA transfer on a channel is restarted by setting the DMST bit in DMSCNT or the DEN bit in DMCRE of
the given DMACm to 1.
After returning the DMAC from the module-stop state or the overall device from all-module clock stop mode, software
standby mode, or deep software standby mode, setting the DMST bit to 1 restarts DMA transfer on channels where
transfer had been suspended.
(3) Canceling DMA transfer
If the DSCLR bit in DMCRB of DMACm is set to 1 with DMA transfer of the channel suspended, the DMA transfer is
canceled and the internal state of the DMAC is initialized. However, only the transfer state of the DMAC's internal
circuits is initialized at this time; that is, all registers are not initialized.
Summary of Contents for RX600 Series
Page 1006: ...RX610 Group R01UH0032EJ0120 ...