A 5-stage ring counter (one-hot) is built using 5 flip-flops connected in a ring. How many unique states does it cycle through?

Introduction / Context:
Ring counters are widely used for sequence generation, time-slot selection, and simple state machines in digital systems. They are “one-hot” by design.

Given Data / Assumptions:

• 5 flip-flops wired as a ring (one-hot configuration).
• Exactly one flip-flop is high at any time; the “1” circulates.

Concept / Approach:

In a ring counter, the number of stable, recurring states equals the number of flip-flops, provided proper initialization to a one-hot state.

Step-by-Step Solution:

Verification / Alternative check:

Simulate the ring on paper or HDL; the single “1” advances one stage per clock, cycling through five states before repeating.

Why Other Options Are Wrong:

• 10 or 32 states: confuse with Johnson counters or general 5-bit counters.
• Infinite: the sequence is finite and periodic.
• 2^5 - 1: applies to maximal-length LFSRs, not ring counters.

Common Pitfalls:

Confusing ring counters with Johnson (twisted ring) counters, which have 2N states.

Final Answer:

5 states