Register Addressing - NEC 78K/0S Series User Manual

3.2.4 Register addressing

[Function]
This addressing is to access a general-purpose register by specifying it as an operand. The general-purpose
register to be accessed is specified with a register specification code in an instruction code or function name.
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 (register specification code) in the
instruction code.
[Operand format]
Operand
r X, A, C, B, E, D, L, H
rp AX, BC, DE, HL
'r' and 'rp' can be described with absolute names (R0 to R7 and RP0 to RP3) as well as functional names (X, A,
C, B, E, D, L, H, AX, BC, DE, and HL).
[Description example]
MOV A, C; When selecting the C register for r
Instruction code
INCW DE; When selecting the DE register pair for rp
Instruction code
36
CHAPTER 3 ADDRESSING
Description
0 0 0 0 1 0 1 0
0 0 1 0 0 1 0 1
1 0 0 0 1 0 0 0
User's Manual U11047EJ3V0UM00
Register specification code
Register specification code