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CLD  -  Clear Direction Instruction


The CLD instruction is used to clear the DF flag. This effects the direction in which data is read using the SI and DI registers.

When Cleared the SI and DI registers are incremented, when the flag is set using STD instruction they are decremented i.e. operate backwards.

STD Op Code is FD to set the flag to 1

CLD Op Code is FC to clear the flag to 0