1
Digital Logic Design
1- Draw the basic model for fundamental mode circuit & explain it.
2- Explain what is hazards & different types of Hazards, how hazards occur in combinational circuit.
3- Define the difficulties arises in the asynchronous sequential circuit.
4- An asynchronous sequential circuit is describe by the excitation and output function describing the circuit are as follows-
Y=x1.x2+(x1+x2)y , z=y
(a) Draw the transition table and output map.
(b) Obtained the flow table of the circuit.
(c) Draw the logic diagram.
5- Short note on race free state assignment and discussed both methods.
2
1- Draw and explain the working of master slave J-K flip-flop.
2- A sequential circuit has three flip-flop, A, B, C; one input x and one output y. The state diagram is shown in. The circuit is designed by treating the unused state as don’t care conditions. The final circuit must be analysed to ensure that it is self-correcting.
0/0 1/1 0/0
1/0 
0/0 0/0 1/1 1/1
1/1 0/0Use D flip-flop in the design.
3- Explain ROM. List the programmable table for BCD to excess-3 code converter using PAL.
3
1- Explain singed binary number representation.
2- Perform the following arithmetic operations in BCD numbers (893-647) using the 10’s complement.
3- The state of a 12-bit register is 010110010111. What is its content if it represents:
(a) Three decimal digit in BCD
4- Perform the arithmetic operations (-29)+(-49) in binary using the signed 2’s complement representation for negative numbers. Convert answer back decimal and verify that they are correct.
5- The hamming code 101101101 is received. Correct it if any error there are four parity bits and odd parity is used.
6- Implement the following Boolean function F together with the don’t care conditions d using no more than two NOR gates:
F(A,B,C,D)=∑( 2,4,6,10,12)
d(A,B,C,D)=∑(0,8,9,13)
