Add add (byte) – Zilog Z80380 User Manual
Page 57
5-23
Z380
™
U
SER
'
S
M
ANUAL
Z
ILOG
DC-8297-03
ADD
ADD (BYTE)
ADD A,src src = R, RX, IM, IR, X
Operation:
A
←
A + src
The source operand is added to the accumulator and the sum is stored in the accumulator.
The contents of the source are unaffected. Two’s complement addition 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 carry from bit 3 of the result; cleared otherwise
V:
Set if arithmetic overflow occurs, that is, if both operands are of the same sign and the
result is of the opposite sign; cleared otherwise
N:
Cleared
C:
Set if there is a carry from the most significant bit of the result; cleared otherwise
Addressing
Execute
Mode
Syntax
Instruction Format
Time
Note
R:
ADD A,R
10000-r-
2
RX:
ADD A,RX
11y11101 1000010w
2
IM:
ADD A,n
11000110 ——n—
2
IR:
ADD A,(HL)
10000110
2+r
X:
ADD A,(XY+d)
11y11101 10000110 ——d—
4+r
I
Field Encodings:
r:
per convention
y:
0 for IX, 1 for IY
w: 0 for high byte, 1 for low byte