GATES AND FLIP FLOP Subject: Computer Architecture

2. 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):

3.  Logical diagram:
 Algebraic function:
y=a.b or y=ab
Truth table:

4.  Logical diagram:
 Algebraic function:
y=a+b
 Truth table:

5.  Logical diagram:
 Algebraic function:
y=a
 Truth table:

6.  Logical diagram:
A y
 Algebraic function:
y=a
 Truth table:
Input output
a y
0 0
1 1

7.  Logical diagram:
 Algebraic function:
y=(ab)
 Truth table:

8.  Logical diagram:
 Algebraic function:
y=(a+b)
 Truth table:

9.  Logical diagram:
 Algebraic function:
y=ab+ab
Truth table:

10.  Logical diagram:
 Algebraic function:
y=ab+ab
Truth table:

11.  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.

12. TABLE:
X Y P Q
0 0 1 1
0 1 1 0
1 0 0 1
1 1 0 1
1 0