Datasheet

Section 7 DMA Controller (DMAC)
Rev.6.00 Mar. 18, 2009 Page 219 of 980
REJ09B0050-0600
7.3.4 DMA Control Registers (DMACRA and DMACRB)
DMACR controls the operation of each DMAC channel.
The DMA has four DMACR registers: DMACR_0A in channel 0 (channel 0A), DMACR_0B in
channel 0 (channel 0B), DMACR_1A in channel 1 (channel 1A), and DMACR_1B in channel 1
(channel 1B).
In short address mode, channels A and B operate independently, and in full address mode,
channels A and B operate together. The bit functions in the DMACR registers differ according to
the transfer mode.
Short Address Mode:
• DMACR_0A, DMACR_0B, DMACR_1A, and DMARC_1B
Bit Bit Name Initial Value R/W Description
7 DTSZ 0 R/W Data Transfer Size
Selects the size of data to be transferred at one
time.
0: Byte-size transfer
1: Word-size transfer
6 DTID 0 R/W Data Transfer Increment/Decrement
Selects incrementing or decrementing of MAR
after every data transfer in sequential mode or
repeat mode. In idle mode, MAR is neither
incremented nor decremented.
0: MAR is incremented after a data transfer
• When DTSZ = 0, MAR is incremented by 1
• When DTSZ = 1, MAR is incremented by 2
1: MAR is decremented after a data transfer
• When DTSZ = 0, MAR is decremented by 1
• When DTSZ = 1, MAR is decremented by 2
5 RPE 0 R/W Repeat Enable
Used in combination with the DTIE bit in
DMABCR to select the mode (sequential, idle, or
repeat) in which transfer is to be performed.
• When DTIE = 0 (no transfer end interrupt)
0: Transfer in sequential mode
1: Transfer in repeat mode
• When DTIE = 1 (with transfer end interrupt)
0: Transfer in sequential mode
1: Transfer in idle mode