Specifications

21
4.0 Glossary (General Denitions and Symbolsl)
SECTION 4 GLOSSARY
LOGIC SYMBOLS
AND GATE
OR GATE
NAND GATE
NOR GATE
NOT
SYMBOL
NAME
DESCRIPTION
(INVERTER)
A
B
X
A
B
X
A
B
X
X
A
B
A X
inverter.
output is true when the input is false. A NOT gate is also called an
The output of a NOT gate is the inverse (opposite) of its input, so the
A NOT gate can only have one input. The 'o' on the output means 'not'.
true when all its inputs are true.
An AND gate can have two or more inputs. The output of an AND gate is
true unless all its inputs are true.
'not' showing that it is a Not AND gate. The output of a NAND gate is
A NAND gate can have two or more inputs. The 'o' on the output means
true when at least one of its inputs is true.
An OR gate can have two or more inputs. The output of an OR gate is
when none of its inputs are true.
'not' showing that it is a Not OR gate. The output of a NOR gate is true
A NOR gate can have two or more inputs. The 'o' on the output means
AND
OUTPUT
A B
0 0 0
0 1 0
1 0 0
1 1 1
INPUT
X = AB
OR
A B
0 0 0
0 1 1
1 0 1
1 1 1
OUTPUTINPUT
X = A+B
NAND
A
B
0
0
1
0
1
1
1
0
1
1
1
0
OUTPUTINPUT
X = A B
NOR
A B
0 0 1
0 1 0
1 0 0
1 1 0
OUTPUTINPUT
X = A + B
NOT
INPUT OUTPUT
A
0 1
1 0
X = A
CONTENTS