STC - Set Carry Flag

Opcode

Instruction

Op/ En

64-Bit Mode

Compat/ Leg Mode

Description

F9

STC

ZO

Valid

Valid

Set CF flag.

Instruction Operand Encoding

Op/En

Operand 1

Operand 2

Operand 3

Operand 4

ZO

N/A

N/A

N/A

N/A

Description

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

Operation 

CF := 1;

Flags Affected

The CF flag is set. The OF, ZF, SF, AF, and PF flags are unaffected.

Exceptions (All Operating Modes)

#UD

If the LOCK prefix is used.