HD6412350 Hitachi, HD6412350 Datasheet - Page 256

• Manufacturer Part Number: HD6412350
• Description: (HD6412350 / HD6432351) 16-BIT MICROCONTROLLER
• Manufacturer: Hitachi

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 : I/O address register
ETCR : Transfer count register
DTDIR : Data transfer direction bit
236
H'FF
: Memory 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
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
Number of transfers
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
Operation