Assignment No. 5 Combinational Functions & Circuits


1.    Design a 4-to-16-line decoder with enable using five 2-to-4 line decoders with enable.

2.    Design an 8-to-1-line multiplexer using a 3-to-8-line decoder and an 8 x 2 AND-OR.

3.    Repeat (2) using two 4-1-line multiplexers and one 2-to-1-line multiplexer.

4.    A combinational circuit is defined by the following three Boolean functions.

Design the circuit with a decoder and external OR gates.

5.    Implement the following Boolean function with an 8-to-1-line multiplexer and a single inverter with variable D as its input:

6.    Implement the Boolean function:

with a 4-to-1-line multiplexer and external gates. Connect inputs A and B to the selection lines. The input requirements for the four data lines will be a function of the variables C and D. The values of these variables are obtained by expressing F as a function of C and D for each of the four cases when AB = 00. 01, 10, and 11 (divide your truth table into groups of two rows each). These functions must be implemented with external gates.

7.    Solve problem (6) using two 3-to-8-line decoders with enables, and inverter, and OR gates with a maximum fan-in of 4.