UPD78F0138 NEC, UPD78F0138 Datasheet - Page 82

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

3.4.2 Register addressing
82
[Function]
[Operand format]
[Description example]
The general-purpose register to be specified is accessed as an operand with the register bank select flags
(RBS0 to RBS1) and the register specify codes (Rn and RPn) of an operation code.
Register addressing is carried out when an instruction with the following operand format is executed. When an
8-bit register is specified, one of the eight registers is specified with 3 bits in the operation code.
‘r’ and ‘rp’ can be described by absolute names (R0 to R7 and RP0 to RP3) as well as function names (X, A, C,
B, E, D, L, H, AX, BC, DE, and HL).
MOV A, C; when selecting C register as r
INCW DE; when selecting DE register pair as rp
Operation code
Operation code
r
rp
Identifier
CHAPTER 3 CPU ARCHITECTURE
0
1
User’s Manual U16228EJ2V0UD
1
0
X, A, C, B, E, D, L, H
AX, BC, DE, HL
1
0
0
0
0
0
Description
0
1
1
0
0
0
Register specify code
Register specify code