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$1)$ Master-Slave FF is designed to avoid race around condition

$2)$ Master-Slave FF is used to store $2$ bit information

Which of the following statement is correct?

What is meaning of $2-bit $ information??

asked ago in Digital Logic by Veteran (114k points) | 52 views
Using a single SR or a single JK flip flop we store exactly one bit info which we output using Q. Here they have asked whether Master-Slave FF would store 2 bit info.
How that is possible??

2 bit is not possible in any case.


because Master an slave cannot work at same time.

Plz explain more. Unable to understand
Yes you are right, we will use the whole setup to store only 1 bit information.
then why r they asking for 2 bit information??
They are asking whether the statement is true or false. Which in this case will be false

@sakharam why false?? Is 2 bit Master-Slave not possible in any case?

The reason we use a master slave configuration is to make level triggered flipflop a negative edge one.

We can use two master slave flip flops to store 2 bit info

The following text is from Digital Design by Morris Mano



Chk this

In truth table of 01 , it is also giving output 01

then how 2 bit output not possible??

Mam this is a single bit output, $\overline{Q_{n+1}}$ will always be a complement of  Q$_{n+1}$.

This does not mean that we are storing two bits. We are storing a bit and its complement.
ok :)

1 Answer

+1 vote
Best answer

$\text{1) Master-Slave FF is designed to avoid race around condition - TRUE}$

In $SR$ flip-flop we have output ends $Q$ and $\overline{Q}$ respectively, when both the inputs are 1 then output is indeterminate. In order to remove this behavior we connect output $Q$ to $R$ and $\overline{Q}$ to S. This creates toggling and the toggling is so fast that we can't even remove it by giving clock pulse of size less than time required to toggle. This toggle is nothing but the race condition. So to avoid this problem we use $\text{Master-Slave FF}$ where the output of $\text{Master FF}$ becomes available at the $\text{SLAVE}$ end after 1 clock cycle.

$\text{2) Master-Slave FF is used to store 2 bit information - FALSE}$

We are storing only 1 bit information, the only difference here is that 1 bit information appears at the output end with a delay of 1 clock cycle.

$\textbf{PS: Edit}$

When the clock pulse is active Master FF output is available but does not appear at output end and during the same cycle Slave FF has output which was produced by Master FF in previous cycle. Once again when clock cycle becomes down, then slave becomes active and Master FF's output will appear the Slave FF end. Hence it appear that it is storing 2 bit information, but actually it is storing 1 bit of information.

answered ago by Active (1.8k points)
selected ago by
2nd point is not clear

@srestha check the answer now I have edited it



check this truth table

in input 01, output also 01

Then how 2 bit output not possible??


What is Flip-flop?

Flip-flops and latches are used as data storage elements. A flip-flop is a device which stores a single bit (binary digit) of data; one of its two states represents a "one" and the other represents a "zero"

So whatever be the internal states we will be able to store only 1 bit of information which will appear as output

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