Clear Direction Flag

Opcode	Encoding	16-bit	32-bit	64-bit	Description
`FC` `CLD`	`zo`	Valid	Valid	Valid	Clear `EFLAGS.DF` (direction flag).
Opcode: `FC` Mnemonic: `CLD` Encoding: `zo` Validity (16/32/64 bit): valid, valid, valid Clear `EFLAGS.DF` (direction flag).

Encoding

Encoding	Operand
`zo`	None

Description

The CLD instruction clears EFLAGS.DF (the direction flag).

Operation

public void CLD()
{
    EFLAGS.DF = 0;
}

Flags Affected

CF (carry flag): Unmodified.
PF (parity flag): Unmodified.
AF (auxiliary flag): Unmodified.
ZF (zero flag): Unmodified.
SF (sign flag): Unmodified.
DF (direction flag): Cleared.
OF (overflow flag): Unmodified.

Exceptions

Real-Address Mode

#UD

If the
LOCK
prefix is used.

Virtual-8086 Mode

#UD

If the
LOCK
prefix is used.

Protected Mode

#UD

If the
LOCK
prefix is used.

Compatibility Mode

#UD

If the
LOCK
prefix is used.

Long Mode

#UD

If the
LOCK
prefix is used.