Computer Architecture

Logic gates are the basic building blocks of any digital system. It is an electronic circuit having one or more than one input and only one output. The relationship between the input and the output is based on a certain logic.

Based on this, logic gates are named as AND gate, OR gate ,Not gate etc.

There are seven basic logical gates: And Or Not gate or inverter Nand gate Nor gate Exclusive-or(xor): Exclusive-nor or (equivalence):

Logical gates:

Logical diagram:

Algebraic function: y=a.b or y=ab

Truth table:

And gate:

Or gate: Logical diagram: Algebraic function: y=a+b Truth table:

Logical diagram: Algebraic function: y=a Truth table:

Not gate or inverter:

Logical diagram: A y Algebraic function: y=a Truth table:

buffer gate:

Input output a y 0 0 1 1

Logical diagram:

Algebraic function: y=(ab) Truth table:

Nand gate:

Logical diagram:

Algebraic function: y=(a+b) Truth table:

Nor gate:

Logical diagram: Algebraic function: y=ab+ab Truth table:

Exclusive-or(xor):

Logical diagram: Algebraic function: y=ab+ab Truth table:

Exclusive-nor or (equivalence):

Flip-flops, also called bitable gates, are digital logic circuits that can be in one of two states. Flip-flops maintain their state indefinitely until an input pulse called a trigger is received.

Flip flop:

TABLE:

X Y P Q

0 0 1 1

0 1 1 0

1 0 0 1

1 1 0 1

1 0