Combinational circuit and Sequential circuit

Two types of circuit used in Computer design

1. Presented By: Poornima . Santhosh

2. COMBINATIONAL CIRCUIT and SEQUENTIAL CIRCUIT

3. COMBINATIONAL CIRCUIT: A combinational circuit is a system containing basic Boolean operations(AND ,OR , Not), some inputs and set of outputs. It is a circuit in which we combine different gates. COMBINATIONAL CIRCUIT Inputs Outputs 1 2 n 1 2 m Block Diagram

4. Characteristic The output of combinational circuit at any instant of time, depends only on the levels present at input terminal. It do not use any memory. The pervious state of Input does not have any effect on the present state of the circuit. It has n number of inputs and m number of outputs. Each output represents a logical function. Combinational circuit implements several different Boolean function.

5. Full Adder Half Adder N bit Subtractor Half Subtractor Full Subtractor Multiplexers Demultiplexers Decoder Encoder Some of the Combinational Circuits

6. SEQUENTIAL CIRCUIT : A circuit whose output depends on the present and all the past inputs .Inorder to remember the past input it uses memory elements. This type of circuit uses past and present inputs , clock, output and memory elements . COMBINATIONAL CIRCUIT MEMORY ELEMENT INPUT OUTPUT CLOCK Block Diagram

7. EG: Flip Flops Television remote In general in channel changing technique when we press channel up or down the circuit will need to know which channel it is currently tuned and the previous channel it was tuned.