CS302 Idea Solution

Cs302 idea solution

Question#1:

Solution:

The characteristic equation of the JK flip-flop is:

and the corresponding truth table is:

Truth table for JK flip_flop_____________________________
J	K	Qnext	Comment
0	0	Qprev	hold state
0	1	0	reset
1	0	1	set
1	1	Qprev	toggle

Question#2:

Provide to-the-point (max 4 to 5 lines) answer to the following:

 What is the main difference between a gated S-R latch and an edge-triggered S-R flip-flop?

 Solution:

There is no real difference.

1- A latch only uses one output

whereas a flip-flop has two.

2-In a latch one of the inputs

is used as a set.

The second is used as a reset.

3-In a flip-flop the first input sets the first output and resets the

second. The second input resets the first output and sets

the second.

4-A number os flipflops are often used as a part of a (shift)

register. Then both outputs are used and the shift is made

by a clockpulse.

5- A flip-flop (and thus a latch) can be edge triggered or

level-triggered. This depends on the internal structure of

the IC.

Q#3

Solution:

 How many flip-flops are required to produce a divide-by-32 device?

Solution:

32=2^5 => 5 bit longNumber divisible is 2*5=10 bit longQuotient & Remainder both are 5 bit eachso total 25 flip-flops at least (+ may be some other auxilliary register also)