CHAPTER 3 CPU ARCHITECTURE
User’s Manual U15331EJ4V1UD 71
3.4.3 Special function register (SFR) addressing
[Function]
The memory-mapped special function registers (SFRs) are addressed with 8-bit immediate data in an
instruction word.
This addressing is applied to the 256-byte space FF00H to FFFFH. However, the SFRs mapped at FF00H to
FF1FH can also be accessed with short direct addressing.
[Operand format]
Identifier Description
sfr Special function register name
[Description example]
MOV PM0, A; When selecting PM0 for sfr
Instruction code 11100111
00100000
[Illustration]
15 0
SFR
Effective
Address 1111111
87
07
OP code
sfr-offset
1