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
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 PD789488
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