Digital Techniques and Microprocessor - PART 11

06:00:00 Nandan Bhalwankar 0 Comments

DelayFlip-flops:

If we use only middle two rows of truth table of S/R or J/K flip-flop, we obtain D flip-flop. It has only 1 data input. Output is obtained at Q_n+1 that is, at the end of clock pulse which is equal to input D_nwhich is applied at beginning or before clock pulse. This is equivalent to saying that input data appears at output at the end of clock pulse. Thus, the transfer of data from input to output is delayed by one clock pulse. Hence, the flip-flop is named as Delay flip-flop (D). Delay flip-flop is either used as a delay device or as a latch to store 1 bit binary information.

Dn	Qn+1
Input	Output
0	0
1	1

7) Toggle Flip-flops:

In J-K flip-flop if J = K the resulting flip-flop is referred to as Toggle flip-flop. It has only 1 input. If T = 1, it acts as a Toggle switch. For every clock pulse output changes. S-R flip-flop cannot be converted directly into Toggle flip-flop since in S, R S = R = 1 is not allowed.

 

Tn	Qn+1
Input	Output
0	Qn
1

Applications of Flip-flops:

1. Bounce elimination switch

2. Latch

3. Register

4. Counter

5. Memory

This was all about the basic gates, their functioning, truth tables and their applications. There are many other applications like Registers, Counters, and Microprocessors which have these logic gates as a basic circuitry in them. There are many integrated circuits and chips which are the heart of many appliances we use daily have logic gates and digital logic. Thus, it has become very important for us to know at least the basics of Boolean logic and logic gates.