NEC 78K/0 Series User Manual page 57

SUB
[Instruction format]
[Operation]
[Operand]
Mnemonic
SUB A, #byte
saddr, #byte
A, r
r, A
A, saddr
Note Except r = A
[Flag]
Z AC
× ×
[Description]
• The source operand (src) specified by the 2nd operand is subtracted from the destination operand (dst)
specified by 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 out of bit 7, the CY flag is set (1). In all other cases, the CY flag is
cleared (0).
• If the subtraction generates a borrow for bit 3 out of bit 4, the AC flag is set (1). In all other cases, the AC
flag is cleared (0).
[Description example]
SUB D, A; The A register is subtracted from the D register and the result is stored in the D register.
CHAPTER 5 EXPLANATION OF INSTRUCTIONS
SUB dst, src
dst, CY ← dst – src
Operand(dst,src)
Note
CY
×
User's Manual U12326EJ4V0UM
Byte Data Subtraction
Mnemonic Operand(dst,src)
SUB A, !addr16
A, [HL]
A, [HL+byte]
A, [HL+B]
A, [HL+C]
Subtract
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