clc

Clear Carry Flag

CLC

Sets the CF flag to 0.

Details

Unconditionally clears the Carry Flag (CF) to 0. Only the CF flag is modified; all other flags and CPU state remain unchanged. Available in all modes (real, protected, and 64-bit).

Pseudocode Operation

CF ← 0

Example

CLC

Encoding

Binary Layout
F8
+0
 
Format Legacy
Opcode F8
Extension Base

Operands

Reference (Intel® SDM)

Instruction Forms

Opcode Instruction Op/En 64/32-bit Mode CPUID Description
F8 CLC ZO Valid Valid Clear CF flag.

Description

Clears the CF flag in the EFLAGS register. Operation is the same in all modes.

Operation

CF := 0;

Flags Affected

The CF flag is set to 0. The OF, ZF, SF, AF, and PF flags are unaffected. Exceptions (All Operating Modes) #UD If the LOCK prefix is used. CLC—Clear Carry Flag Vol. 2A 3-140