Bsc CSIT Semester 1 – Digital Logic – Unit 4: Combinational Logic (5 Hrs.)

Explain design procedure of combinational circuits. Design a combinational circuit with three inputs x, y, and z, and three outputs, A, B, and C. When the binary input is 0, 1, 2, or 3, the binary output is one greater than the input. When the binary input is 4, 5, 6, or 7, the binary output is one less than the input.

What is decoder? Describe the 3 to 8 line decoder circuit.

What is combinational circuit? Design a combinational circuit with four inputs lines that represent a decimal digit in BCD and four output lines that generate the 1's complement of the input binary patterns.

Implement the Boolean function F(P,Q,R,S)= Σ (3,4,6,8,9,14) using:a. 8 to 1 multiplexerb. PLAc. Decoder

What is combinational circuit? Design a combinational circuit with four inputs lines that represent a decimal digit in BCD and four output lines that generate the 1's complement of the input binary patterns.

Design a full subtractor with necessary tables and logic diagram.

What is decoder circuit? Design 3 to 8 decoder circuit.

Write short notes on:

$\quad$ a. State Diagram

$\quad$ b. Encoder

$\quad$ c. Parallel Adder

Implement F = Σ(0, 2, 3, 4, 7) using

a. Multiplexer
b. Decoder
c. PLA

Design a combinational circuit with three inputs and one output. The output is 1 when the binary value of the inputs is an odd number.

Design a combinatorial circuit that generates 9's complement of a BCD number.

Implement the following functions using PLAw (A, B, C, D) = ∑(3,12,13)x (A, B, C, D)= ∑ (7,8,9,10,11,12,13,14,15)y (A, B, C, D) = ∑ (0,2,3,4,5,6,7,8,10,11,15)z (A, B, C, D) = ∑ (1,2,8,12,13)

Design a full subtractor circuit with three inputs x, y, Bin and two outputs Diff and Bout. The circuit subtracts x-y-Bin where Bin is the input borrow, Bout is the output borrow, and Diff is the difference.

Design 4-bit even parity generator.

Draw a block diagram, truth table and logic circuit of 1*16 Demultiplexer and explain its working principle.

Design a combinational circuit with three inputs and six outputs. The output binary number should be the square of the input binary number.

Design and explain the Decimal adder with truth table and suitable diagram.

Implement the following function F = Σ(1, 2, 3, 4, 8) using

$\quad$ a. Decoder

$\quad$ b. Multiplexer

$\quad$ c. PLA

The following is a truth table of a 3-input,4 output combinational circuit. Tabulate the PAL programming table for the circuit and mark for the circuit and mark the fuses to be blown in a PAL diagram.

Design a combinational circuit with three inputs, x, y, and z, and three outputs, A, B, and C. When the binary input is 0, 1, 2, or 3, the binary output is one greater than the input. When the binary input is 4, 5, 6, or 7, the binary output is one less than the input.