Z8
®
CPU
User Manual
UM001604-0108
Instruction Description
158
Add
Syntax
ADD dst, src
Instruction Format
Operation
dst
←
dst + src
The source operand is added to the destination operand. Two’s complement addition is
performed. The sum is stored in the destination operand. The contents of the source oper-
and are not affected.
Address modes R or IR can be used to specify a 4-bit Working Register. In this format, the
source or destination Working Register operand is specified by adding
1110b
(
Eh
) to the
high nibble of the operand. For example, if Working Register R12 (CH) is the destination
operand, then
ECh
is used as the destination operand in the Op Code.
Cycles
OPC (Hex)
Address Mode
dst
src
OPC
dst src
6
02
r
r
6
03
r
lr
OPC
src
dst
10
04
R
R
10
05
R
IR
OPC
dst
src
10
06
R
IM
10
07
IR
IM
Flags Description
C
Set if there is a carry from the most significant bit of the result;
cleared otherwise
Z
Set if the result is zero; cleared otherwise
S
Set if the result is negative; cleared otherwise
V
Set if an arithmetic overflow occurs, that is, if both operands are
of the same sign and the result is of the opposite sign; cleared
otherwise
D
Always cleared
H
Set if there is a carry from the most significant bit of the low order
four bits of the result; cleared otherwise
E
src
or
E
dst
Note:
