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Exclusive or (xor), Preface, Updates to arithmetic status bits – Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers User Manual

Page 168

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Preface

MicroLogix 1000 Programmable Controllers User Manual

9–20

Exclusive Or (XOR)

The value at source A is Exclusive ORed bit by bit with the value at source B and
then stored in the destination.

Truth Table

Dest = A XOR B

A

B

Dest

0

0

0

1

0

1

0

1

1

1

1

0

Source A and B can either be a word address or a constant; however, both sources
cannot be a constant. The destination must be a word address.

Updates to Arithmetic Status Bits

With this Bit:

The Controller:

S:0/0

Carry (C)

always resets.

S:0/1

Overflow (V)

always resets.

S:0/2

Zero (Z)

sets if result is zero; otherwise resets

S:0/3

Sign (S)

sets if result is negative (most significant bit is set); otherwise
resets.

Execution Times

(

µ

sec) when:

True

False

33.64

6.92

XOR

BITWISE EXCLUS OR
Source A

Source B

Dest