Topic: Digital Circuits
What is the value of the register formed from D flip-flops using $Q_0$, $Q_1$ and $Q_2$ as output ($Q_0 Q_1 Q_2$) after 14 cycles? (A 3-bit shift register with the inverted output of the last stage fed back to the input of the first stage)
- A. 110
- B. 000
- C. 001
- D. 011
Answer: A. 110
Explanation: The circuit represents a 3-bit Johnson counter, which has a modulo of $2n = 6$ states. Assuming it starts at 000, the sequence repeats every 6 cycles. After 12 clock cycles, the counter returns to the initial state 000. After the 13th cycle, the state is 100. After the 14th cycle, the state shifts to 110.