Machine/Processor Control Instructions

Machine/Processor Control Instructions – These instructions are used to set and reset some internal flags of the processor and to put the processor in Halt or No Operation states.

NOP	No operation
Operation	No operation is performed
Length	1 byte
Addressing mode	None
Flags	Flags are not affected

HLT	Stop the execution
Operation	Make the processor in a wait state until any externally initiated signal is given.
Length	1 byte
Addressing mode	None
Flags	Flags are not affected

STC	Set carry flag
Operation	CY ← 1
Length	1 byte
Addressing mode	Implicit addressing mode
Flags	The carry flag is set; all other flags are not affected.

CMC	Complement the carry flag
Operation	CY ← CY
Length	1 byte
Addressing mode	Implicit addressing mode
Flags	The carry flag is complemented; all other flags are not affected.