Z8
®
CPU
User Manual
UM001604-0108
Instruction Description
168
Complement
Syntax
COM dst
Instruction Format
Operation
dst
←
NOT dst
The contents of the destination operand are complemented (one’s complement). All 1 bits
are changed to 0, and all 0 bits are changed to 1.
Address modes R or IR can be used to specify a 4-bit Working Register. In this format, the
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.
Example 1
If Register
08h
contains
24h
(
00100100b
), the statement:
COM 08h
Op Code: 60 08
leaves the value
DBh
(
11011011
) in Register
08h
. The S Flag is set, and the Z and V
Flags are cleared.
Cycles
OPC
(Hex)
Address Mode
dst
OPC
dst
6
60
R
6
61
IR
Flag
Description
C
Unaffected
Z
Set if the result is zero; cleared otherwise.
S
Set if result bit 7 is set; cleared otherwise.
V
Always reset to 0.
D
Unaffected
H
Unaffected
E
dst
Note: