R01UH0823EJ0100 Rev.1.00
Page 357 of 1823
Jul 31, 2019
RX23W Group
18. DMA Controller (DMACA)
18.3
Operation
18.3.1
Transfer Mode
(1) Normal Transfer Mode
In normal transfer mode, one data is transferred by one transfer request. A maximum of 65535 can be set as the number
of transfer operations using the DMCRAL of DMACm. When these bits are set to 0000h, no specific number of transfer
operations is set; data transfer is performed with the transfer counter stopped (free running mode). Setting DMCRB of
DMACm is invalid in normal transfer mode. Except in free running mode, a transfer end interrupt request can be
generated after completion of the specified number of transfer operations.
summarizes the register update operation in normal transfer mode, and
shows the operation in
normal transfer mode.
Note 1. Offset addition can be specified only for DMAC0.
Figure 18.2
Operation in Normal Transfer Mode
Table 18.3
Register Update Operation in Normal Transfer Mode
Register
Function
Update Operation after Completion of a Transfer by One Transfer Request
DMACm.DMSAR
Transfer source address
Increment/decrement/fixed/offset addition*
DMACm.DMDAR
Transfer destination address
Increment/decrement/fixed/offset addition*
DMACm.DMCRAL
Transfer count
Decremented by one/not updated (in free running mode)
DMACm.DMCRAH
—
Not updated (Not used in normal transfer mode)
DMACm.DMCRB
—
Not updated (Not used in normal transfer mode)
DMSAR
Transfer source data area
DMDAR
Transfer
Transfer destination data area
Data 1
Data 2
Data 3
Data 4
Data 5
Data 6
Data 1
Data 2
Data 3
Data 4
Data 5
Data 6