r4f2426 Renesas Electronics Corporation., r4f2426 Datasheet - Page 376

• Manufacturer Part Number: r4f2426
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

Section 7 DMA Controller (DMAC)
7.5.4
Repeat mode can be specified by setting the RPE bit in DMACR to 1, and clearing the DTIE bit in
DMABCRL to 0. In repeat mode, MAR is updated after each byte or word transfer in response to
a single transfer request, and this is executed the number of times specified in ETCRL. On
completion of the specified number of transfers, MAR and ETCRL are automatically restored to
their original settings and operation continues. One address is specified by MAR, and the other by
IOAR. The transfer direction can be specified by the DTDIR bit in DMACR. Table 7.7
summarizes register functions in repeat mode.
Table 7.7
Rev. 1.00 Sep. 19, 2008 Page 348 of 1270
REJ09B0466-0100
Register
23
23
H'FF
Repeat Mode
15
7
7
ETCRAH
ETCRAL
Register Functions in Repeat Mode
MAR
IOAR
0
0
0
0
Source
address
register
Destination
address
register
Holds number of
transfers
Transfer counter
DTDIR = 0 DTDIR = 1 Initial Setting
Function
Destination
address
register
Source
address
register
Start address of
transfer destination
or transfer source
Start address of
transfer source or
transfer destination
Number of transfers Fixed
Number of transfers Decremented every
Operation
Incremented/
decremented every
transfer.
Initial setting is
restored when the
value reaches
H'0000
Fixed
transfer.
Loaded with
ETCRH value when
the value reaches
H'00