HD64F2149 Datasheet, PDF (198/1035 Pages) Renesas Technology Corp – Hitachi 16-Bit Single-Chip Microcomputer

7.2 Register Descriptions
7.2.1 DTC Mode Register A (MRA)
Bit
Initial value
Read/Write
7
SM1
Unde-
fined
—
6
SM0
Unde-
fined
—
5
DM1
Unde-
fined
—
4
DM0
Unde-
fined
—
3
MD1
Unde-
fined
—
2
MD0
Unde-
fined
—
1
DTS
Unde-
fined
—
0
Sz
Unde-
fined
—
MRA is an 8-bit register that controls the DTC operating mode.
Bits 7 and 6—Source Address Mode 1 and 0 (SM1, SM0): These bits specify whether SAR is
to be incremented, decremented, or left fixed after a data transfer.
Bit 7
SM1
0
1
Bit 6
SM0
—
0
1
Description
SAR is fixed
SAR is incremented after a transfer
(by 1 when Sz = 0; by 2 when Sz = 1)
SAR is decremented after a transfer
(by 1 when Sz = 0; by 2 when Sz = 1)
Bits 5 and 4—Destination Address Mode 1 and 0 (DM1, DM0): These bits specify whether
DAR is to be incremented, decremented, or left fixed after a data transfer.
Bit 5
DM1
0
1
Bit 4
DM0
—
0
1
Description
DAR is fixed
DAR is incremented after a transfer
(by 1 when Sz = 0; by 2 when Sz = 1)
DAR is decremented after a transfer
(by 1 when Sz = 0; by 2 when Sz = 1)
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