Intel 253666-024US - Manual (Page 153)

Vol. 2A 3-107
INSTRUCTION SET REFERENCE, A-M
CLD—Clear Direction Flag
CLD—Clear Direction Flag
Description
Clears the DF flag in the EFLAGS register. When the DF flag is set to 0, string opera-
tions 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.
Opcode Instruction 64-Bit
Mode
Compat/
Leg Mode
Description
FC CLD Valid Valid Clear DF flag.