CHAPTER 3 CPU ARCHITECTURE
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
sfr
Description
Special function register name
[Description example]
MOV PM0, A; When selecting PM0 for sfr
Instruction code
1
0
1
0
1
1
0
0
0
0
1
0
1
0
1
0
[Illustration]
7
0
OP code
sfr-offset
SFR
15
1
8 7
0
Effective
Address
1
1
1
1
1
1
1
User’s Manual U15075EJ1V0UM00
73
NEC [ NEC ]
