Designing a MOD-32 binary counter — number of flip-flops How many flip-flops are required to construct a MOD-32 binary counter (i.e., a counter that cycles through 32 distinct states)?

Difficulty: Easy

Correct Answer: 5

Explanation:


Introduction / Context:
Binary counters implemented with flip-flops have a number of states equal to 2^n, where n is the number of flip-flops (bits). Determining the number of flip-flops needed for a target modulus is a foundational skill for digital timing and sequencing design.


Given Data / Assumptions:

  • We need a counter with 32 distinct states (MOD-32).
  • Each flip-flop contributes one binary digit (bit).
  • States grow as powers of two: 2^n.


Concept / Approach:
Find the smallest n such that 2^n ≥ 32. Because 2^5 = 32, five flip-flops are exactly sufficient and produce the required modulus without wasted states.


Step-by-Step Solution:

1) Evaluate powers: 2^4 = 16 (insufficient).2) Next power: 2^5 = 32 (matches requirement).3) Therefore, n = 5 flip-flops.4) Implement as ripple or synchronous as needed for timing constraints.


Verification / Alternative check:
Simulate a 5-bit counter; it cycles through 00000 to 11111 (32 states) before repeating.


Why Other Options Are Wrong:

  • 3 and 6 do not yield 32 states (2^3=8, 2^6=64).
  • 45 is unrelated and not a number of flip-flops.


Common Pitfalls:
Confusing decimal modulus with binary powers; forgetting that extra states appear if n is larger than necessary.


Final Answer:
5

More Questions from Counters

Discussion & Comments

No comments yet. Be the first to comment!
Join Discussion