Difficulty: Easy
Correct Answer: 15
Explanation:
Introduction / Context:Binary counters use a certain number of flip-flops to represent states. With 4 bits, the representable unsigned values range from 0 to 2^4 - 1. Knowing the maximum value helps determine range, modulus, and overflow behavior in digital designs.
Given Data / Assumptions:
Concept / Approach:For N bits, the highest unsigned value is 2^N - 1. Substituting N = 4 gives 2^4 - 1 = 16 - 1 = 15. In binary, this is 1111. Many counters therefore have a modulus of 16 when all 4-bit states are used.
Step-by-Step Solution:
Compute 2^4 = 16.Subtract 1 to get 15.Confirm representation: 1111₂ = 8 + 4 + 2 + 1 = 15.Thus, the largest decimal value is 15.Verification / Alternative check:List the 4-bit codes from 0000 to 1111 and sum the weights of 1111 to verify 15. Simulation or a counter datasheet (MOD-16) corroborates this.
Why Other Options Are Wrong:
8: This is 1000₂, not the maximum 4-bit value.16: Requires 5 bits to represent 10000₂.32: Requires 6 bits to represent 100000₂.Common Pitfalls:Off-by-one errors when applying 2^N; confusing the count of states (16) with the largest numeric value (15).
Final Answer:15
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