D12320VF25IV Datasheet, PDF (306/1304 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Section 7 DMA Controller (Not Supported in the H8S/2321)
MARA and MARB specify the start addresses of the transfer source and transfer destination,
respectively, as 24 bits. MAR can be incremented or decremented by 1 or 2 each time a byte or
word is transferred, or can be fixed.
Incrementing, decrementing, or holding a fixed value can be set separately for MARA and
MARB.
Whether a block is to be designated for MARA or for MARB is specified by the BLKDIR bit in
DMACRA.
To specify the number of transfers, if M is the size of one block (where M = 1 to 256) and N
transfers are to be performed (where N = 1 to 65,536), M is set in both ETCRAH and ETCRAL,
and N in ETCRB.
Figure 7.13 illustrates operation in block transfer mode when MARB is designated as a block area.
Rev.6.00 Sep. 27, 2007 Page 274 of 1268
REJ09B0220-0600