Special Function Register (Sfr) Addressing - NEC mPD789101 User Manual

4.4.3 Special function register (SFR) addressing

[Function]
Memory-mapped special function registers (SFRs) are addressed with 8-bit immediate data in an instruction
word.
This addressing is applied to the 240-byte spaces FF00H to FFCFH and FFE0H to FFFFH. However, SFRs
mapped at FF00H to FF1FH can be accessed with short direct addressing.
[Operand format]
Identifier
sfr Special function register name
[Description example]
MOV PM0, A; When selecting PM0 for sfr
[Illustration]
7
OP code
sfr-offset
15
Effective
1 1 1
address
68
CHAPTER 4 CPU ARCHITECTURE
Description
Instruction code
0
8 7
1 1 1 1 1
User's Manual U13045EJ2V0UM00
1 1 1 0 0 1 1
0 0 1 0 0 0 0
0
1
0
SFR