x86 Instruction Set Reference

CLD - Clear Direction Flag

Opcode Mnemonic Description
FC CLD Clear DF flag.
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 
DF = 0;
Flags affected

The DF flag is set to 0. The CF, OF, ZF, SF, AF, and PF flags are unaffected.

Exceptions
None.