LOGICAL INSTRUCTIONS IN 8051 MICRO-CONTROLLER

✏️LOGICAL INSTRUCTIONS IN 8051 MICRO-CONTROLLER

🧲Logic means evaluating the conditions using reasonable thinking and making a decision based on the evaluation

🧲Binary deals with data that takes only two discrete values as true or false

🧲Three basic logical operations AND ,OR and NOT operator.

🧲8051 supports logical operations such as AND,OR ,EX-OR and NOT

🧲These operations can be performed on a byte or bit at a time.

✏️BYTE OPERATIONS

👉Operation specified in an instruction is performed on all 8 bits in a BYTE. 

👉General format for these instruction are:

                     ANL destination, source

                      ORL destination, source

                        XRL destination, source

✏️AND OPERATION

👉AND instruction for different addressing modes:    

ANL A, #data

ANL A, #10H

ANL A, Rn

     ANL A, R0

ANL A, @Ri

    ANL, @R1

ANL A, direct

    ANL A, 20H

✏️OR OPERATION 

ORL A, #data

        ORL A,#10H

ORL A, Rn

          ORL A, R0

ORL A, @Ri

             ORL A, @R1

ORL A, direct

ORL A, 20H

ORL direct, #data

  ORL 30H, #0E6H

ORL direct, A

ORL 10H, A

✏️EX-OR OPERATION

XRL A, #data

        XRL A, #10H

XRL A, Rn

         XRL A,R0

XRL A, @Ri

     XRL A, @R1

XRL A, direct

XRL A, 20H

XRL direct, #data

XRL 30H, #0E6H

XRL direct, A

XRL 10H, A

✏️UNARY OPERATION

1.Clear: used to clear the contents of accumulation

CLR A //Clear accumulator

2. Complement(NOT operation): used the generation 1’s complement of the data in an accumulator

CPL A//Complement A

3.Rotate:

Rotate accumulator left by one bit

RL A //rotate a one bit position to the left.

Example ,

                MOV A, #43H

RL A

RL A

b) Rotate accumulator right by one bit

RR A// Rotate A one bit position to the right

Example,

MOV A, #35H

RR A

C) Rotate accumulator left through carry by one bit

RLC A// Rotate A one bit position to the left through carry flag

Example,

CLR C

MOV A,#0D6H

RLC A

D)Rotate accumulator right through carry by one bit

RRC// Rotate A one bit position to the right through carry flag

Example,

SETB C

MOV A,#62H

RRC A

4. SWAP

It is a instruction which swaps the nibbles of register A. 

For example,

A=53H(Before execution)

SWAP A

A=35H(After execution)