nop
No Operation (Thumb)
NOP
No op (Thumb 16-bit).
Details
Performs no operation; used for code alignment, timing adjustments, or as a placeholder instruction. No registers are modified and no condition flags are affected. Available in both A32 and Thumb-2 states.
Pseudocode Operation
// No operation; pipeline advance only
Example
NOP
Encoding
Binary Layout
10111111
0000
0000
Operands
Reference (Arm AArch32 ISA)
Instruction Forms
| Encoding | Instruction | ISA | Bit pattern | ||
|---|---|---|---|---|---|
| 0x0320F000 | NOP{<c>}{<q>} | A32 | cond | 00110 | 0 | 10 | 00 | 00 | 1 | 1 | 1 | 1 | 000000000000 | ||
| 0xBF00 | NOP{<c>}{<q>} | T32 | 10111111 | 0000 | 0000 | ||
| 0xF3AF8000 | NOP{<c>}.W | T32 | 111100111010 | 1 | 1 | 1 | 1 | 10 | 0 | 0 | 0 | 000 | 0000 | 0000 |
Description
No Operation does nothing. This instruction can be used for instruction alignment purposes.
Operation
if ConditionPassed() then
EncodingSpecificOperations();
// Do nothing