Consider the following counter. The counter is ____.

Answer: The counter is neither self-starting nor free running.

Explanation:

• Type of counter: This is a Johnson counter whose state graph splits into two disjoint loops.

• Top loop (6 states): 000 → 100 → 110 → 111 → 011 → 001 → back to 000.

• Bottom loop (2 states): 010 ↔ 101.

• Why not free running: A free-running counter cycles through all 2^n states in a single loop. Here the states are split into a 6-state loop and a 2-state loop, so there is no single cycle containing all states.

• Why not self-starting: A self-starting counter will reach the main counting sequence from any initial state. If the counter starts in 010 or 101 it stays trapped in the two-state loop with no path to the six-state loop, so it will not reach the intended counting sequence from every initial state.

• Conclusion: Because the state graph is split and some states cannot reach the main loop, the counter is neither self-starting nor free running.