Flip-flop truth tables,excitation tables and conversions.

Flip-Flop truth tables and excitation tables:

1 1)    R-S flip-flop: -The truth table and excitation tables of R-S flip are

Truth table of R-S filp-flop

Sn	Rn	Qn+1
0	0	Qn
0	1	0
1	0	1
1	1	?

Excitation table of R-S flip-flop

Present output	Next output	input
Qn	Qn+1	Sn	Rn
0	0	0	X
0	1	1	0
1	0	0	1
1	1	X	0

Note: - Here X is either 0 or 1.

2) J-K Flip-Flop: -  The truth tables and excitation of j-k flip flops are

Truth table

Jk	Kn	Qn+1
0	0	Qn
0	1	0
1	0	1
1	1	~Qn

Excitation table of j-k flip-flop

Present output	Next output	input
Qn	Qn+1	Jn	Kn
0	0	0	X
0	1	1	X
1	0	X	1
1	1	X	0

3) T Flip-flop:- Truth table and excitation table of T Flip-flop

                                               Truth table

Tn	Qn+1
0	Qn
1	~Qn

                                                Excitation table

present output Qn	Next output Qn+1	input Tn
0	0	0
0	1	1
1	0	1
1	1	0

4) D Flip-flop:- The truth table and excitation tables of D flip-flops are

                                      Truth table of D flip-flop

Dn	Qn+1
0	0
1	1

                                           

                                            Excitation table of D flip-flop

present output Qn	Next output Qn+1	input Tn
0	0	0
0	1	1
1	0	0
1	1	1

These are S-R, J-K, T, D flip flops truth tables and excite tabes by using these tables we can convert from one to other like S-R to J-K etc.

Above both truth tables and excitation tables are very important for conversion from one flip to another flip-flops.

Few important conversions are:

1) S-R Flip-flop to T Flip-flop: - The excitation table for S-R flip-flop to T flip-flop conversion is

Input T	Present state Qn	Next state Qn+1	Flip-flop inputs
			S	R	S	R
0	0	0	0	0	0	X
			0	1
0	1	1	0	0	X	0
			1	0
1	0	1	1	0	1	0
1	1	0	0	1	0	1

This is conversion table for S-R flip-flop to T flip-flop conversion. After draw a k- map of s and R you will get a circuit T flip-flop using S-R flip-flop.

2)S-R Flip-flop to D Flip-flop: - The excitation table for S-R flip-flop to D flip-flop conversion is

Input D	Present state Qn	Next state Qn+1	Flip-flop inputs
			S	R	S	R
0	0	0	0	0	0	X
			0	1
0	1	0	0	1	0	1
1	0	1	1	0	1	0
1	1	1	0	0	X	0
			1	0

This is conversion table for S-R flip-flop to D flip-flop conversion. After draw a k- map of s and R you will get a circuit D flip-flop using S-R flip-flop.

3)S-R Flip-flop to J-K Flip-flop: - The excitation table for S-R flip-flop to J-K flip-flop conversion

Input		Present state	Next state	Flip-flop inputs
J	K	Qn	Qn+1	S	R	S	R
0	0	0	0	0	0	0	X
				0	1
0	0	1	1	0	0	X	0
				1	0
0	1	0	0	0	0	0	X
				0	1
0	1	1	0	0	1	0	1
1	0	0	1	1	0	1	0
1	0	1	1	0	0	X	0
				1	0
1	1	0	1	1	0	1	0
1	1	1	0	0	1	0	1

This is the excitation table for S-R flip-flop to J-K flip-flop. Remember before learn conversation table just note down truth table and excitation tables of the flip flops.

4)T flip-flop to D flip-flop: - The excitation table for T flip-flop to

D flip-flop conversation

Input D	Present state Qn	Next state Qn+1	Flip-flop input T
0	0	0	0
0	1	0	1
1	0	1	1
1	1	1	0

5)D flip-flop to T flip-flop: - The excitation table for D flip-flop to T flip-flop conversion is

Input T	Present state Qn	Next state Qn+1	Flip-flop input T
0	0	0	0
0	1	1	1
1	0	1	1
1	1	0	0

6)J-k flip flop to T flip-flop: -The excitation table for j-k flip flop to T flip flop conversation

Input T	Present state Qn	Next state Qn+1	Flip-flop inputs
			J	K	J	K
0	0	0	0	0	0	X
			0	1
0	1	1	0	0	X	0
			1	0
1	0	1	1	0	1	X
			1	1
1	1	0	0	1	X	1
			1	1

Before learn the conversation just read and note down the truth tables and excitation tables of every flip flops .

7) J-K flip flop to D flip flop: - The excitation table for j-k flip flop to D flip flop conversation  

Input D	Present state Qn	Next state Qn+1	Flip-flop inputs
			J	K	J	K
0	0	0	0	0	0	X
			0	1
0	1	0	0	1	X	1
			1	1
1	0	1	0	0	0	X
			0	1
1	1	1	0	0	X	0
			1	0

  

Almost i provide all conversions in case of any missing conversions design your own truth table using truth tables and excitation tables.

Remember before learn the conversions just note down the truth tables and excitation tables of total flip flops which is very helpful for understanding the flip flop conversions.