R01UH0823EJ0100 Rev.1.00
Page 370 of 1823
Jul 31, 2019
RX23W Group
18. DMA Controller (DMACA)
18.3.7
Activating the DMAC
shows the register setting procedure.
Figure 18.12
Register Setting Procedure
DM[1:0] bits in DMACm.DMAMD
SM[1:0] bits in DMACm.DMAMD
DARA[4:0] bits in DMACm.DMAMD
SARA[4:0] bits in DMACm.DMAMD
m: DMAC channel (m = 0 to 3)
Set the transfer source start address.
DMACm.DMSAR
Set the control register for the peripheral function without
starting it.
DCTG[1:0] bits in DMACm.DMTMD
SZ[1:0] bits in DMACm.DMTMD
DTS[1:0] bits in DMACm.DMTMD
MD[1:0] bits in DMACm.DMTMD
Set the transfer destination start address.
DMACm.DMCRA
Set the offset value.
DMACm.DMOFR
To use DMA transfer end interrupts
Set 1 to DTIE bit in DMACm.DMINT.
Set DTE bit in DMACm.DMCNT to 1.
Set DMST bit in DMAST to 1.
Enable DMA transfer end interrupts.
Set the peripheral module as a DMACm request
source.
Enable DMA transfer.
Enable DMAC operation.*
1
DMACm.DMCRB
Start the peripheral function as a DMACm request
source.
Transfer destination address update mode bits
Transfer source address update mode bits
Destination address extended repeat area bits
Source address extended repeat area bits
Clear the DTE bit in DMACm.DMCNT to 0.
Disable DMA transfers.
Set the IRQ pin function without enabling it.
Set the IRQ pin function using the interrupt
controller (ICU).
Set the interrupt request as a DMA request source
in the DMAC activation source select register
(ICU.DMRSRm) using the ICU.
Set the DMAC activation source.
Enable the IRQ pin as a DMACm request source.
Transfer request select bits
Data transfer size bits
Repeat area select bits
Transfer mode select bits
DMACm.DMDAR
Set the number of transfer operations.
To use block transfer mode or repeat transfer mode
Set the number of block transfer operations.
To use the address update function with offset
To use DMA transfer escape interrupts
RPTIE bit in DMACm.DMINT
SARIE bit in DMACm.DMINT
DARIE bit in DMACm.DMINT
Set the ESIE bit in DMACm.DMINT to 1.
Set the repeat size end interrupt
Set the transfer source address extended repeat area overflow interrupt
Set the transfer destination address extended repeat area overflow interrupt
Enable the DMA transfer escape end interrupt
For activation other than by software
Clear the interrupt enable bit (ICU.IERn.IENj) as an activation
source to 0, then perform the settings below.
Enable the interrupt bit for
the activation source.
Set IENj bit in ICU.IERn to 1.
For activation by software
On completion of the initial settings, writing 1 to the DMA software
activation bit (DMACm.DMREQ.SWREQ) starts DMA transfer.
To use peripheral function
interrupts as DMA activation
sources
To use external pin interrupts as
DMA activation sources
To use on-chip peripheral
interrupts or external pin
interrupts as DMA activation
sources
To use peripheral function
interrupts as DMA activation
sources
To use external pin interrupts as
DMA activation sources
To use on-chip peripheral
interrupts or external pin
interrupts as DMA activation
sources
Start of initial settings
End of initial settings
Settings required for
each activation source
Common settings
for DMAC
Note 1. Setting of the DMAST.DMST bit does not necessarily have to follow the settings for the individual activation sources.