Half Adder using Decoder
2-bit Calculator
Simple 2-bit Calculator with a decoder for a 7 segment display.
circuit Debug testing
2x4 Decoder using Basic Gates
Experiment No. 7: Implementation of 2x4 decoder using basic gates.
Done by:
Saranga K. Mahanta
Scholar Id: 18-14-038
Circuit 3.3
Use two 2-to-4 DECODERS (with Enable bits) one INVERTER gate and
two AND gates to implement a 3-to-8 DECODER (with Enable bit).
Circuit 3.4
Use a 3-to-8 DECODER (and an OR gate) to implement the following
function: 𝐹 = ∑𝑚(1,2,3,5,7).
2:4 Decoder ( Binary Decoder)
For a decoder, If the input is a N bit binary number, then the output will be one the lines of the 2^N output lines.
So, for a 2-bit binary input, there will be 2^2 output lines and only one of the output lines will be active according to the binary combination of the inputs. This type of decoder is known as 2 to 4 decoder.
A
B
Q0
Q1
Q2
Q4
0
0
1
0
0
0
0
1
0
1
0
0
1
0
0
0
1
1
1
0
0
0
1
8:1 Multiplexer
Consider a 8:1 multiplexer that takes 8 two-bit inputs (T8 to T1), three-bit control signal (S) and has an output (Out). This Type of multiplexer is known as a 8 to 1 multiplexer. The truth table is given below:
S2
S1
S0
OUT
0
0
0
T1
0
0
1
T2
0
1
0
T3
0
1
1
T4
1
0
0
T5
1
0
1
T6
1
1
0
T7
1
1
1
T8
Decoder and Encoder
Decoder:-
A decoder is a combinational circuit. It has n input and to a maximum m = 2n outputs. Decoder is identical to a demultiplexer without any data input. It performs operations which are exactly opposite to those of an encoder.
Block diagram:-
Truth table:-
Diagram:-
*formed using simulator.
Encoder:-
Encoder is a combinational circuit which is designed to perform the inverse operation of the decoder. An encoder has n number of input lines and m number of output lines. An encoder produces an m bit binary code corresponding to the digital input number. The encoder accepts an n input digital word and converts it into an m bit another digital word.
Block diagram:-
Truth table:-
Diagram:-
*formed using simulator.
Experiment 2
Encoder/Decoder
Decoder
Combinational Circuit
Encoder, Decoder, Convertor, Full Adder using Decoder
