CSA Application of Flip Flop

1. Q5. Applications of Flip Flops
Application of the flip flop circuit mainly involves in bounce elimination switch,
data storage, data transfer, latch, registers, counters, frequency division,
memory, etc.
A register is a collection of a set of flip flops used to store a set of bits. For
instance, if you want to store an N – bit of words you need N number of FFS.
AFF can store only one bit of data (0 or 1). A number of FFs are used when the
number of data bits to be stored. A register is a set of FFs used to store binary
data. The data storage capacity of a register is a set of bits of digital data that
it can retain. Loading a register can be defined as setting or resetting the
separate FFs, i.e, giving data into the register so the status of the FF
communicates to the bits of data to be stored.
RAM is used in computers, information processing systems, digital control
systems it is necessary to store digital data and recover the data as preferred.
FFS can be used to make memories in which information can be stored for any
required length of time and then deliver whenever required.
Counters are the digital circuits which are used to count the number of events.
These are nothing but a series of flip-flops (JK or D or T) arranged in a definite
manner. A single flip-flop has two states 0 and 1, which means that it can
count up to two. Thus one flip-flop forms a 2-bit (or Modulo 2, MOD 2)
counter.
Event detectors are the circuits which aid in determining the occurrence of a
particular event. These devices are required to change their state when an
event occurs and should further be held in the same state till that event gets
cleared. Flip-flops are well-known to preserve their state until the appearance
of a suitable condition at their inputs, which means they can act as event
detectors. For example one can use a D flip-flop to detect the event of
switching ‘on’ of the light.

2. Data Synchronizers
All the outputs of a particular combinational circuit are expected to change
their states at the same instant. However sometimes due to the varying gate
delays, the outputs of the combinational circuit might change their states at
different instants of time. This would further cause unexpected behavior
resulting in wrong outputs. This can be avoided by using synchronous D flip-
flops at the outputs acting as data synchronizers
Frequency Divider
Consider a positive edge triggered JK flip-flop whose inputs are tied-together
and driven high, as shown in Figure 6. In this state, the output of JK flip-flop
will toggle for each positive-edge of the clock signal (red lines in the figure).
From the waveform it is evident that if the input clock period is Tin, then the
time period of output waveform Tout is twice of it. Thus one gets fout = fin/2
which implies that input frequency is divided by 2. In other words, after
passing through a single flip-flop, the input frequency will be halved. On the
same grounds one can conclude that after passing through the n flip-flops,
the input frequency will be divided by 2n
which results in fout = fin/2n
.
Apart from these applications, a few flip-flops have definite uses like
1. D flip-flop can be used to create delay-lines which are used in digital
signal processing systems. This application arises readily due to the fact
that the output at the synchronous D flip-flop is nothing but the input
delayed by one-clock cycle. Thus by cascading n such flip-flops, output
can be delayed by n clock cycles which in turn produces the required
amount of delay.
2. Generally the mechanical switches used to enter the values into the
digital system are prone to bouncing problem where the switch-
contacts vibrate while closing/opening the switch. This leads to the
variation in the output voltage causing the logical inputs to alternate
between 0 and 1. This results in unexpected system behavior which can
be avoided by connecting a RS flip-flop between the switch and the
digital circuit to act as a switch debouncer.