CLD—Clear Direction Flag
| Opcode |
Instruction |
Op/En |
64-bit Mode |
Compat/Leg Mode |
Description |
| FC |
CLD |
NP |
Valid |
Valid |
Clear DF flag. |
Instruction Operand Encoding
| Op/En |
Operand 1 |
Operand 2 |
Operand 3 |
Operand 4 |
| NP |
NA |
NA |
NA |
NA |
Description
Clears the DF flag in the EFLAGS register. When the DF flag is set to 0, string operations increment the index registers (ESI and/or EDI). Operation is the same in all non-64-bit modes and 64-bit mode.
Operation
DF ← 0;
Flags Affected
The DF flag is set to 0. The CF, OF, ZF, SF, AF, and PF flags are unaffected.
Exceptions (All Operating Modes)
| #UD |
If the LOCK prefix is used. |