ZiLOG Z80380 User Manual page 206

Z
ILOG
SUB
SUBTRACT (BYTE)
SUB A,src
← A - src
Operation: A
The source operand is subtracted from the accumulator and the difference is stored in the
accumulator. The contents of the source are unaffected. Two's complement subtraction is
performed.
Flags: S: Set if the result is negative; cleared otherwise
Z: Set if the result is zero; cleared otherwise
H: Set if there is a borrow from bit 4 of the result; cleared otherwise
V: Set if arithmetic overflow occurs, that is, if the operands are of different signs and the
result is of the same sign as the source; cleared otherwise
N: Set
C: Set if there is a borrow from the most significant bit of the result; cleared otherwise
Addressing
Mode Syntax
R: SUB A,R
SUB A,RX
RX:
IM: SUB A,n
IR: SUB A,(HL)
X: SUB A,(XY+d)
Field Encodings: r: per convention
y: 0 for IX, 1 for IY
w: 0 for high byte, 1 for low byte
5-172
src = R, RX, IM, IR, X
Instruction Format
10010-r-
11y11101 1001010w
11010110 ——n—
10010110
11y11101 10010110 ——d—
Execute
Time Note
2
2
2
2+r
4+r I
Z380 ™
U ' M
SER S ANUAL
DC-8297-03