UPD78F0138 NEC, UPD78F0138 Datasheet - Page 85

• Manufacturer Part Number: UPD78F0138
• Description: (UPD78xxxx) 8-Bit Single-Chip Microcontrollers
• Manufacturer: NEC

3.4.5 Special function register (SFR) addressing
Effective address
[Function]
[Operand format]
[Description example]
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.
MOV PM0, A; when selecting PM0 (FF20H) as sfr
[Illustration]
15
7
1
Operation code
sfr
sfrp
Identifier
1
1
OP code
sfr-offset
1
Special function register name
16-bit manipulatable special function register name (even address
only)
1
1
CHAPTER 3 CPU ARCHITECTURE
1
1
0
User’s Manual U16228EJ2V0UD
1
0
8 7
1
0
1
1
1
0
0
0
Description
1
0
1
0
0
0
OP code
20H (sfr-offset)
0
SFR
85