Microprocessors and Microcontrollers 19th Aug.

Increasing Counter(0-F)

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XX: MVI B,10H

XRA A

XY: 01H

INR A

DCR B

JNZ XY

JMP XX

Decreasing Counter(F-0)

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XY: MVI A,10H

XX: DCR A

OUT 01H

JNZ XX

OUT 01H

JMP XY

NOTE: INR/DCR Does not affect CARRY FLAG

Increasing Counter(00-FF)

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XRA A

XY: OUT 01H

INR A

JMP XY

Decreasing Counter(FF-00)

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MVI A,FFH

XX: OUT 01H

DCR A

JMP XX

FOUR NEW INSTRUCTIONS

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1.RAL (Rotate Accumulator Left with carry)

2.RLC (Rotate Accumulator Left)

3.RAR (Rotate Accumulator Right with Carry)

4.RRC (Rotate Accumulator Right)

Few diagrams will make u clear....

RAL:

RLC:

RAR AND RRC are just the opposite of RAL AND RLC...

Always Remember:

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Left Shift: A number gets multiplied by 2

Right Shift: A number gets divided by 2

05H X 04 H

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MVI A,05H

RLC

RLC