Difficulty: Easy
Correct Answer: 8
Explanation:
Introduction / Context:
Each flip-flop holds one binary digit. Regardless of ripple or synchronous style, n flip-flops can encode up to 2^n distinct states. This question checks basic recall of binary capacity for a 3-bit counter, a recurring building block in larger designs and in divide-by-N frequency generation.
Given Data / Assumptions:
Concept / Approach:
The number of representable states equals the number of distinct combinations of 3 bits: 2 * 2 * 2 = 8. In free-running counters, these states cycle naturally from 000 to 111 and back to 000.
Step-by-Step Solution:
Verification / Alternative check:
Enumerate explicitly: 000, 001, 010, 011, 100, 101, 110, 111 → 8 states.
Why Other Options Are Wrong:
2 and 4 correspond to 1-bit and 2-bit capacities.
16 corresponds to 4 bits (2^4).
Common Pitfalls:
Confusing modulus with number of flip-flops; forgetting that truncation (e.g., MOD-6) requires extra decode beyond the natural 2^n states.
Final Answer:
8
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