Datasheet

Section 11 Data Transfer Controller (DTC)
Page 368 of 982 REJ09B0465-0300 Rev. 3.00
Sep 17, 2010
H8S/20103, H8S/20203, H8S/20223, H8S/20115, H8S/20215, H8S/20235 Group
11.8 Usage Notes
11.8.1 Module Standby Mode Setting
DTC operation can be disabled or enabled using the module standby control register. The initial
value is for DTC operation to be disabled. When the DTC is used, cancel module standby mode.
Register access is disabled in module standby mode. Module standby mode cannot be set while
the DTC is activated. For details, see section 6, Power-Down Modes.
11.8.2 DTCE Bit Setting
For DTCE bit setting, use bit manipulation instructions such as BSET and BCLR. If all interrupts
are disabled, multiple activation sources can be set at one time (only at the initial setting) by
writing data after executing a dummy read on the relevant register.
11.8.3 DTC Activation by SCI3, IIC2/SSU and A/D Converter Interrupt Sources
Interrupts and activation sources of the SCI3, IIC2/SSU, and A/D converter are cleared when the
DTC reads or writes the prescribed register. Therefore, when the DTC is activated by an interrupt
or activation source, the interrupt or activation source will be retained if a read/write of the
relevant register is not included in the last chained data transfer.
The above operation is performed regardless of the DISEL bit setting.
11.8.4 Limitation on Usage of the Interrupt Vector Offset Register (VOFR)
When the DTC is used while the interrupt vector offset register (VOFR) holds an offset-address
setting, the VOFR setting has no effect. The DTC refers to the vector definition in the vector
address area defined by the initial value (H'0000) of VOFR, which leads to the execution of
exception processing.
Whenever the DTC is used, set the VOFR to H'0000 (its default value).