H8S2456 Datasheet, PDF (380/1376 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8S Family / H8S/2400 Series

Section 7 DMA Controller (DMAC)
Figure 7.8 shows an example of the setting procedure for repeat mode.
Repeat mode setting
Set DMABCRH
[1]
Set transfer source
and transfer destination [2]
addresses
Set number of transfers [3]
Set DMACR
[4]
Read DMABCRL
[5]
[1] Set each bit in DMABCRH.
• Clear the FAE bit to 0 to select short address
mode.
• Specify enabling or disabling of internal
interrupt clearing with the DTA bit.
[2] Set the transfer source address and transfer
destination address in MAR and IOAR.
[3] Set the number of transfers in both ETCRH and
ETCRL.
[4] Set each bit in DMACR.
• Set the transfer data size with the DTSZ bit.
• Specify whether MAR is to be incremented or
decremented with the DTID bit.
• Set the RPE bit to 1.
• Specify the transfer direction with the DTDIR
bit.
• Select the activation source with bits DTF3 to
DTF0.
[5] Read the DTE bit in DMABCRL as 0.
[6] Set each bit in DMABCRL.
• Clear the DTIE bit to 0.
• Set the DTE bit to 1 to enable transfer.
Set DMABCRL
[6]
Repeat mode
Figure 7.8 Example of Repeat Mode Setting Procedure
Rev. 1.00 Sep. 19, 2008 Page 350 of 1342
REJ09B0467-0100