Specifications

mikroElektronika | Free Online Book | PIC Microcontrollers | Introduction: World of Microcontrollers

If a program, logic NOT operation is performed on one byte. The result is a byte with inverted

bits. If byte is considered to be a number, the inverted value is actually a complement of that

number, i.e. the complement of a number is what is needed to add to it to make it reach the

maximal 8 bit value (255).

EXCLUSIVE OR Gate

The EXCLUSIVE OR (XOR) gate is a bit complicated comparing to other gates. It represents a combination of all

the previously described gates. A logic one (1) appears on its output only when the inputs have different logic

states.

In a program, this operation is commonly used to compare two bytes. Subtraction may be

used for the same purpose (if the result is 0, bytes are equal). The advantage of this logic

operation is that there is no danger to subtract larger number from smaller one.

A register or a memory cell is an electronic circuit which can memorize the state of one byte.

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