CHAPTER 4 CPU ARCHITECTURE
User’s Manual U14826EJ5V0UD
54
4.4.3 Special function register (SFR) addressing
[Function]
A memory-mapped special function register (SFR) is addressed with the 8-bit immediate data in an instruction
word.
This addressing is applied to the 256-byte space FF00H to FFFFH. However, 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 1
1
1
0
0
1
1
1
0
0
1
0
0
0
0
0
[Illustration]
15
0
SFR
Effective
address
1
1
1
1
1
1
1
8 7
0
7
OP code
sfr-offset
1
Содержание PD789860
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