Consider a 3-bit counter designed using T flip-flops as shown (Tp = R, Tq = P′, Tr = Q′, all clocked together). If the initial state PQR is 000, what are the next three states?

1. A011, 101, 000
2. B001, 010, 111
3. C011, 101, 111
4. D001, 010, 000

Pick an option to check yourself, or open the answer below.

Show answer & explanation

Correct answer: A. 011, 101, 000

Explanation

From the circuit, Tp = R, Tq = P′ and Tr = Q′; a T flip-flop toggles when T = 1. 000: Tp = 0, Tq = 1, Tr = 1 → 011. 011: Tp = 1, Tq = 1, Tr = 0 → 101. 101: Tp = 1, Tq = 0, Tr = 1 → 000.