Originally posted by octega:
I try to explain one, JK to D Conversion
[b]Step 1
First plot JK-FF table (this is not truth table)
Input, J & K
Present State,Q
Next State, Q+1
J K Q Q+1
0 0 0 0
0 0 1 1
0 1 0 0
0 1 1 0
1 0 0 1
1 0 1 1
1 1 0 1
1 1 1 0
Step 2
From there derive the excitation table for JK-FF
Q -> Q+1 J K
0 0 0 X
0 1 1 X
1 0 X 1
1 1 X 0
X-Don't care
Step 3
Now look at D-FF's Table
D Q Q+1
0 0 0
0 1 0
1 0 1
1 1 1
Step 4
Using the JK-FF Excitation table fill up D-FF's Q to Q+1.
D Q Q+1 J K
0 0 0 0 X
0 1 0 X 1
1 0 1 1 X
1 1 1 X 0
Step 5
Use the K-Map, simplified the 2 sets
D Q J
0 0 0
0 1 X
1 0 1
1 1 X
D Q K
0 0 X
0 1 1
1 0 X
1 1 0
You will get the JK-FF
J=D, K=D'
This mean that the input signal of the D-FF, D feeds into 2 input
of the JK-FF.
-D signal into J input of the JK-FF
-Invert D signal into K input of the JK-FF
Tada! You got a
D-FF using JK-FF
I hope you can get what I mean, qutie hard to explain without
diagrams. 
Repeat the same concept for all types of FF, be it JK to D or T to
RS, this concept applies for all. [/b]
WAH SEH!!! impressive man! 
*~Clap~Clap~Clap~*
