NEC 78K/0 Series User Manual page 62

Nec computer hardware user's manual
Hide thumbs Also See for 78K/0 Series:
Table of Contents

Advertisement

CMP
[Instruction format]
[Operation]
[Operand]
Mnemonic
CMP
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.
The subtraction result is not stored anywhere and only the Z, AC and CY flags are changed.
• If the subtraction result 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]
CMP FE38H, #38H;
62
CHAPTER 5 EXPLANATION OF INSTRUCTIONS
CMP dst, src
dst – src
Operand(dst,src)
Note
CY
×
38H is subtracted from the contents at address FE38H and only the flags are changed
(comparison of contents at address FE38H and the immediate data).
User's Manual U12326EJ4V0UM
Byte Data Comparison
Mnemonic
Operand(dst,src)
CMP
A, !addr16
A, [HL]
A, [HL+byte]
A, [HL+B]
A, [HL+C]
Compare

Advertisement

Table of Contents
loading

Table of Contents