No Operation
NOP
13-181
Assembly Language Instructions
Syntax
NOP
src
Operation
No ALU or multiplier operations.
AR
n is modified if src is specified in indirect mode.
Operands
src general addressing modes (G):
0 0
register(no operation)
1 0
indirect (modify AR
n, 0
≤
n
≤
7)
(disp = 0–255, IR0, IR1)
Opcode
31
24 23
16
8 7
0
15
0 0 0
0 1
0
0
1
1
src
G
0 0
0
0
0
Description
If the
src operand is specified in the indirect mode, the specified addressing
operation is performed, and a dummy memory read occurs. If the
src operand
is omitted, no operation is performed.
Cycles
1
Status Bits
LUF
Unaffected
LV
Unaffected
UF
Unaffected
N
Unaffected
Z
Unaffected
V
Unaffected
C
Unaffected
OVM
Operation is not affected by OVM bit value.
Example 1
NOP
Before Instruction
After Instruction
PC
3A
PC
3B
Example 2
NOP *AR3
– –
(1)
Before Instruction
After Instruction
AR3
80 9900
AR3
80 98FF
PC
5
PC
6
Mode Bit