H8S-2350 RENESAS [Renesas Technology Corp], H8S-2350 Datasheet - Page 273

• Manufacturer Part Number: H8S-2350
• Description: 16-Bit Single-Chip Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

7.5.3
Idle mode can be specified by setting the RPE bit and DTIE bit in DMACR to 1. In idle mode, one
byte or word is transferred in response to a single transfer request, and this is executed the number
of times specified in ETCR.
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 idle mode.
Table 7.7
Legend:
MAR:
IOAR: I/O address register
ETCR: Transfer count register
DTDIR: Data transfer direction bit
MAR specifies the start address of the transfer source or transfer destination as 24 bits. MAR is
neither incremented nor decremented each time a byte or word is transferred.
IOAR specifies the lower 16 bits of the other address. The 8 bits above IOAR have a value of
H'FF.
Register
23
23
H'FF
Memory address register
15
15
Idle Mode
Register Functions in Idle Mode
MAR
ETCR
IOAR
0
0
0
DTDIR = 0
Source
address
register
Destination
address
register
Transfer counter
Function
DTDIR = 1
Destination
address
register
Source
address
register
Rev. 3.00 Sep 15, 2006 page 239 of 988
Initial Setting
Start address of
transfer destination
or transfer source
Start address of
transfer source or
transfer destination
Number of transfers
Section 7 DMA Controller (DMAC)
REJ09B0330-0300
Operation
Fixed
Fixed
Decremented
every transfer;
transfer ends
when count
reaches H'0000