Hardware manual

Microcomputer Technical Q&A
6
Q&A No.: QAH8S-005
Category: CPU
Subject: H8S/2000 CPU Normal Mode
Question
Are any precautions required when making a transition from H8/300 Series to H8S/2000 Series
normal mode?
Answer
In H8S normal mode, address registers are recognized as being 32 bits long. Therefore, the
following changes are necessary when using an H8/300 assembler program.
• Register indirect
Example: MOV.B @R0,R1L → MOV.B @ER0,R1L
An error is not flagged during assembly.
Access is possible regardless of the contents of the extended register (E0).
• ADDS/SUBS instruction
Example: ADDS.W R0 → ADDS.L ER0
or
INC.W R0
• SP (stack pointer)
Example: MOV.W #16,SP → MOV.L #:32,SP
or
MOV.W #:16,R7
Applicable Products
Applicability Series Applicability Series Applicability Series
Yes Entire H8S Series H8S/2655 H8S/2350
H8S/2355 H8S/2357 H8S/2345
H8S/2245 H8S/2148 H8S/2144
H8S/2138 H8S/2134 H8S/2128
H8S/2124 — — — —