Datasheet

Section 9 Data Transfer Controller (DTC)

R01UH0309EJ0500 Rev. 5.00 Page 479 of 1408

Sep 24, 2012

H8S/2456, H8S/2456R, H8S/2454 Group

9.2 Register Descriptions

DTC has the following registers.

• DTC mode register A (MRA)

• DTC mode register B (MRB)

• DTC source address register (SAR)

• DTC destination address register (DAR)

• DTC transfer count register A (CRA)

• DTC transfer count register B (CRB)

These six registers cannot be directly accessed from the CPU. When activated, the DTC reads a

set of register information that is stored in an on-chip RAM to the corresponding DTC registers

and transfers data. After the data transfer, it writes a set of updated register information back to the

RAM.

• DTC enable registers A to I (DTCERA to DTCERI)

• DTC vector register (DTVECR)

• DTC control register (DTCCR)

9.2.1 DTC Mode Register A (MRA)

MRA selects the DTC operating mode.

Bit Bit Name Initial Value R/W Description

SM1

SM0

Undefined

⎯

Source Address Mode 1 and 0

These bits specify an SAR operation after a data

transfer.

0x: SAR is fixed

10: SAR is incremented after a transfer

(by +1 when Sz = 0; by +2 when Sz = 1)

11: SAR is decremented after a transfer

(by –1 when Sz = 0; by –2 when Sz = 1)