Datasheet

Section 9 Data Transfer Controller (DTC)
R01UH0309EJ0500 Rev. 5.00 Page 495 of 1408
Sep 24, 2012
H8S/2456, H8S/2456R, H8S/2454 Group
9.5.2 Repeat Mode
In repeat mode, one operation transfers one byte or one word of data. Table 9.5 lists the register
function in repeat mode. From 1 to 256 transfers can be specified. Once the specified number of
transfers has ended, the initial state of the transfer counter and the address register specified as the
repeat area is restored, and transfer is repeated. In repeat mode the transfer counter value does not
reach H'00, and therefore CPU interrupts cannot be requested when DISEL = 0.
Table 9.5 Register Function in Repeat Mode
Name Abbreviation Function
DTC source address register SAR Designates source address
DTC destination address register DAR Designates destination address
DTC transfer count register AH CRAH Holds number of transfers
DTC transfer count register AL CRAL Designates transfer count
DTC transfer count register B CRB Not used
SAR
or
DAR
DAR
or
SAR
Repeat area
Transfer
Figure 9.7 Memory Mapping in Repeat Mode