conversion of flip flop
TRANSCRIPT
CONVERSION OF FLIP FLOP
Batch:B3 PREPRED BY:- (1)Panchal manthan-140123109008 (2)Panchal jay-140123109007 (3) Patel nikunj-140123109010
Guided by:- Prof. shweta khakhakhar
INTRODUCTION
Basic info. of conversion SR FF to T FF conversion SR FF to JK conversion
CONVERSION OF FLIP FLOPS
The conversion from one type of flip flop to the other (say SS FF to JK FF) needs a systematic approach using the excitation tables and K map simplifications.
Given flip-flop
Flip-flopConversion logic(Combinational circuit)
General model used to convert one type of FF to the other
{Flip-flopData inputs
}Outputs
Required Flip-Flop
Q
Q_
Fig. shows a generalized model for conversion from one flip flop to the other.
As shown in fig. the required flip flop is actually a combination of the given flip flop and a combinational logic circuit using gates.
Such a combinational is called as the flip flop conversion logic.
The input to FF conversion logic are the flip flop data inputs and the outputs of given flip flop.
The conversion logic is designed by combining the excitation tables of both the flip flop i.e. the given FF and the desired FF.
The truth table of the conversion logic has data inputs and Q and Q outputs of the given FF as inputs whereas the inputs of the given FF are the outputs of the truth table.
Then we draw the K map for each output and obtain the simplified expressions.
The conversion logic is then implemented using gates.
_
SR FLIP FLOP TO T FLIP FLOP
Step 1 : Write the truth table :-
Outputs
Inputs T S RPresent state QnNext state Qn+1
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
×
×
Truth table for SR FF to T FF
Step 2 : Write the K maps and obtain the expressions for S and R :-
Qn
QnT T
××
0
0 0
0
0
0
0
0
11
1
1
1
1
S= T Qn
R= T Qn_
For S output
For R output
(a) K map for S
(b) K map for R
Step 3 : Draw the logic diagram :- The logic diagram is shown in fig.
T flip flop
}Outputs
Conversion from SR flip flop to T flip flop
SR FF
SR FLIP FLOP TO JK FLIP FLOP
Inputs Outputs
J K Present state Qn
Next state Qn+1
S R
0 0 0
0 0 ×
0 1 0 0 0 ×
1 0 0 1 1 0
1 1 0 1 1 0
0 1 1 0 0 1
1 1 1 0 0 1
0 0 1 1 × 0
1 0 1 1 × 0
Step 2 : K maps and simplification :-
Qn
KJ 00 01 11 10
0
1
0 0
0
0
1 1
×
×
_S= J Qn
(a) K map for S
(b) K map for R
For S output
For R output
Qn
KJ 00 01 11 10
×
1
0 1
10 0
0
0
R= K Qn
×
Step 3 : Logic diagram :- The logic diagram of SR to JK flip flop is given in fig.
SR to JK flip flop conversion
CLK
}Outputs
J
K
S Q
R Q_
Conversion logic
JK flip flop
SR FF
