Hardware manual

Microcomputer Technical Q&A
90
Q&A No.: QAH8S-216
Category: DTC
Subject: Order of Setting Register Information
Question
Is there a particular order for setting DTC register information?
Answer
There is no particular order, but the following point should be noted.
If the DTC mode registers (MRA/MRB) are set first, followed by the DTC source address register
(SAR) and DTC destination address register (DAR):
Since SAR and DAR are 24-bit registers, when SAR and DAR are set with a longword instruction
(MOV.L), the previously set MRA and MRB information will be corrupted. This can be avoided
by making the SAR and DAR settings by longword access first, followed by the MRA and MRB
settings.
Applicable Products
Applicability Series Applicability Series Applicability Series
Entire H8S Series Yes H8S/2655 Yes H8S/2350
Yes H8S/2355 Yes H8S/2357 Yes H8S/2345
Yes H8S/2245 Yes H8S/2148 H8S/2144
Yes H8S/2138 H8S/2134 Yes H8S/2128
H8S/2124 — — — —