How to add CLEAR, PRESET terminals in J-K FLIP FLOP

I want to make MOD-3 counter with 2 J-K flip flop, 1 and gate like picture that I upload

but in library there is no CLR,PR port in J-K flip flop. How can i make this?

Answer 1

[Kunal Kandhari]

If you want to create a MOD-3 counter using J-K flip-flops in Simulink and as there is no direct CLR (Clear) or PR (Preset) port in the J-K flip-flop block, you can implement the clear and preset functionality using additional logic gates.

Here's how you can create a MOD-3 counter using J-K flip-flops:

1. Create the J-K Flip-Flops:

• Place two J-K Flip-Flop blocks from the Simulink library onto your model.

2. Connect the Clock Signal:

• Connect a clock signal to the clock (CLK) inputs of both J-K Flip-Flops.

3. Implement the Clear and Preset Functionality:

• Since the J-K Flip-Flop block in Simulink might not have direct CLR (Clear) or PR (Preset) ports, you can use additional logic gates to achieve these functions.
• For the first J-K Flip-Flop (FF1):
• Connect the J input to an AND gate:
• One input of the AND gate should be your desired preset signal.
• The other input of the AND gate should be your clock signal inverted using a NOT gate.
• Connect the K input to an AND gate:
• One input of the AND gate should be your desired clear signal.
• The other input of the AND gate should be your clock signal inverted using a NOT gate.
• For the second J-K Flip-Flop (FF2):
• Connect the J input to an AND gate:
• One input of the AND gate should be your desired preset signal.
• The other input of the AND gate should be the output of FF1 (Q1).
• Connect the K input to an AND gate:
• One input of the AND gate should be your desired clear signal.
• The other input of the AND gate should be the output of FF1 (Q1).

4. Connect the Feedback Logic:

• Connect the Q output of FF1 to the J input of FF2.
• Connect the Q output of FF2 back to the K input of FF2.

5. Create the Output:

• Connect the Q outputs of the J-K Flip-Flops to your output or display blocks to observe the counter's behavior.

By following these steps, you can create a MOD-3 counter using J-K flip-flops in Simulink, implementing clear and preset functionality using additional logic gates as needed. Be sure to configure the preset and clear signals according to your specific requirements.

Answer 2

[Prinsca]

what if it is a d flip flop and I want to create a preset signal