Difficulty: Easy
Correct Answer: False
Explanation:
Introduction / Context:
Sequential elements can have inputs that are either synchronous (qualified by a clock or gate) or asynchronous (acting immediately regardless of clock). Mislabeling these behaviors leads to design errors and timing violations. This question examines the common confusion surrounding gated SR flip-flops and asynchronous controls like PRE/CLR.
Given Data / Assumptions:
Concept / Approach:
By definition, synchronous inputs affect the state only in relation to a gating signal or clock. In a gated SR flip-flop, S and R are evaluated only when the gate is active; otherwise the output holds. Asynchronous inputs bypass the gate and can change the state immediately at any time. Therefore, calling a gated SR flip-flop “asynchronous” because it responds immediately is incorrect.
Step-by-Step Solution:
Verification / Alternative check:
Consult timing diagrams: setup/hold times are defined relative to the gate for S and R, confirming synchrony. PRE/CLR timing is specified independently, highlighting their asynchronous nature.
Why Other Options Are Wrong:
Common Pitfalls:
Mixing up level-sensitive gating (synchronous) with asynchronous override signals; assuming any instantaneous response implies “asynchronous.”
Final Answer:
False
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