NEC 78K/0S Series User Manual page 68

SUB
[Instruction format]
[Operation]
[Operand]
Mnemonic
SUB A, #byte
saddr, #byte
A, r
A, saddr
[Flag]
Z AC
× ×
[Description]
•
The source operand (src) specified with the 2nd operand is subtracted from the destination operand (dst)
specified with the 1st operand and the result is stored in the destination operand (dst) and the CY flag.
The destination operand can be cleared to 0 by equalizing the source operand (src) and the destination
operand (dst).
•
If the subtraction shows that dst is 0, the Z flag is set (1). In all other cases, the Z flag is cleared (0).
•
If the subtraction generates a borrow at bit 7, the CY flag is set (1). In all other cases, the CY flag is cleared
(0).
•
If the subtraction generates a borrow from bit 4 to bit 3, the AC flag is set (1). In all other cases, the AC flag
is cleared (0).
[Description example]
SUB A, D; The D register is subtracted from the A register and the result is stored in the A register.
68
CHAPTER 5 EXPLANATION OF INSTRUCTIONS
SUB dst, src
dst, CY ← dst – src
Operand (dst, src)
CY
×
User's Manual U11047EJ3V0UM00
Mnemonic Operand (dst, src)
SUB A, !addr16
A, [HL]
A, [HL + byte]
Subtract
Byte Data Subtraction