Datasheet

78K0/Ix2 CHAPTER 3 CPU ARCHITECTURE
R01UH0010EJ0500 Rev.5.00 92
Feb 28, 2012
3.4.5 Special function register (SFR) addressing
[Func
tion]
A memory-mapped special function register (SFR) is 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, the SFRs
mapped at FF00H to FF1FH can be accessed with short direct addressing.
[Operand format]
Identifier Description
sfr Special function register name
sfrp 16-bit manipulatable special function register name (even address only)
[Description example]
MOV PM0, A; when selecting PM0 (FF20H) as sfr
Operation code 1 1110110 OP code
0 0100000 20H (sfr-offset)
[Illustration]
15
0
SFR
Effective address
1
111111
87
07
OP code
sfr-offset
1