8051 CLR Instruction

Clear

Instruction	CLR A
Function	Clear Accumulator
Bytes	1
Cycles	1
Encoding	1 1 1 0 0 1 0 0
Operation	A = 0
Description	CLR A clears the Accumulator (all bits set to 0).
Flags Affected	C AC F0 RS1 RS0 OV P
Example	The Accumulator contains 5CH (01011100B). The following instruction, CLR A leaves the Accumulator set to 00H (00000000B).
Bytes: Number of bytes required to encode the instruction. Cycles: Number of instruction cycles required to execute the instruction. Note that there are 12 oscillator cycles to one instruction cycle on a standard 8051. Encoding: Lists the byte encoding for the instruction. Operation: Lists, step-by-step, the operations performed by the instruction. Flags Affected: are highlighted in Bold

Instruction	CLR bit
Function	Clear bit
Bytes	2
Cycles	1
Encoding	1 1 0 0 0 0 1 0 bit_address
Operation	(bit) = 0
Description	CLR bit clears the indicated bit (reset to 0). No other flags are affected. CLR can operate on the carry flag or any directly addressable bit.
Flags Affected	C AC F0 RS1 RS0 OV P
Example	Port 1 has previously been written with 5DH (01011101B). The following instruction, CLR P1.2 leaves the port set to 59H (01011001B). CLR 01h
Bytes: Number of bytes required to encode the instruction. Cycles: Number of instruction cycles required to execute the instruction. Note that there are 12 oscillator cycles to one instruction cycle on a standard 8051. Encoding: Lists the byte encoding for the instruction. Operation: Lists, step-by-step, the operations performed by the instruction. Flags Affected: are highlighted in Bold

Instruction	CLR C
Bytes	1
Cycles	1
Encoding	1 1 0 0 0 0 1 1
Operation	C = 0
Flags Affected	C AC F0 RS1 RS0 OV P
Example	CLR C
Bytes: Number of bytes required to encode the instruction. Cycles: Number of instruction cycles required to execute the instruction. Note that there are 12 oscillator cycles to one instruction cycle on a standard 8051. Encoding: Lists the byte encoding for the instruction. Operation: Lists, step-by-step, the operations performed by the instruction. Flags Affected: are highlighted in Bold

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Related topics:
8051 Logical Operation Instructions   |   8051 ANL Instruction   |   8051 ORL Instruction   |   8051 XRL Instruction   |   8051 CPL Instruction   |   8051 RL Instruction   |   8051 RR Instruction   |   8051 RLC Instruction   |   8051 RRC Instruction   |   8051 SWAP Instruction

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List of topics: 8051

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