HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 293

• Manufacturer Part Number: HD6412320
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family H8S-2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

7.5.4
Repeat mode can be specified by setting the RPE bit in DMACR to 1, and clearing the DTIE bit 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 ETCR. 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 7.8 summarizes register functions in repeat mode.
Table 7.8
Register
23
23
Legend:
MAR:
IOAR:
ETCR: Execute transfer count register
DTDIR: Data transfer direction bit
H'FF
Memory address register
I/O address register
15
Repeat Mode
MAR
Register Functions in Repeat Mode
IOAR
7
7
ETCRH
ETCRL
0
0
0
0
DTDIR = 0 DTDIR = 1 Initial Setting
Source
address
register
Destination
address
register
Holds number of
transfers
Transfer counter
Section 7 DMA Controller (Not Supported in the H8S/2321)
Function
Destination
address
register
Source
address
register
Rev.6.00 Sep. 27, 2007 Page 263 of 1268
Start address of
transfer destination
or transfer source
Start address of
transfer source or
transfer destination
Number of transfers
Number of transfers
Operation
Incremented/
decremented every
transfer. Initial
setting is restored
when value reaches
H'0000
Fixed
Fixed
Decremented every
transfer. Loaded with
ETCRH value when
count reaches H'00
REJ09B0220-0600