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# =Electronics Hardware Questions=

Q:How to convert D-latch into JK-latch and JK-latch into D-latch?

A: from H.T.

```Compare the truth tables of D-latch and JK-latch accordingly:

clk	D	Q
==================
+	0	0
+	1	1

clk	J	K	Q
=========================
+	0	0	hold
+	0	1	0
+	1	0	1
+	1	1	switch to opposite

Using these truth tables it is easy to convert JK-latch into D-latch.
_______
D		|	|   Q
___________|J	|----
|  	|	|
__|__     > clk	|   _
\   / 	|	|   Q
\ /    ___|K	|----
v    |	|_______|
o    |
|____|

To convert D-latch into JK-latch some extra logic is required.
The following table shows the relation between J,K and D

J	K	D
=================
0	0	Q
0	1	0
1	0	1
1	1	!Q

_______________________________
|                               |
___|___		 _______    |
|	|		|	|   |
_J__|       |_______________|D    Q |---'
| A	|		|	|
|	|		|	|
K	|	|		|clk  _	|
----|   	|	      --|     Q |--.
|_______|		|_______|  |
|			     	   |
|_______________________________|

Based on the diagram and the table it is not too hard to implement block A
using a MUX.
J and K are the control signals and 1,0,Q,!Q are the data inputs.

```