You are required to design a 4-bit even up-counter using D flip flop by converting combinational circuit to sequential circuit. The counter will only consider even inputs and the sequence of inputs will be 0-2-4-6-8-10-0. You are required to perform following tasks: 1. Draw the State diagram. 2. Generate State & Transition Table. 3. Generate simplified Boolean Expression. 4. Design the final Circuit diagram.

Firstly we need to draw the state diagram or the transition table. It clearly states through 4 bit even up counter that the next state of 0000 is 0010, and of 0010 is 0100 and so on. So we have the state diagram and the transition table, and thus answer for 1st and 2nd question.

Now through the Karnaugh map, we get the input circuit for D1, D2, D3, and D4. And these are mentioned in the attachment. Remember D outputs the same. which is the input. Thus, we have the answer for 3rd question. And then we draw the diagram, which can be found in the attachment. And this is the answer for the fourth question.