Digital Timing — “Precise timing is not important in digital signals.” Evaluate this statement based on setup/hold, propagation delay, and clocking constraints.

Difficulty: Easy

Correct Answer: Incorrect

Explanation:


Introduction:
While logic levels are binary, the when of transitions is critical. Synchronous systems rely on clocks; even asynchronous systems require bounded delays for correct handshaking. This statement tests understanding that timing integrity is essential in digital design.

Given Data / Assumptions:

  • Digital devices have setup/hold time requirements at registers.
  • Nets have finite propagation delays and skew.
  • Clocks define sampling instants for sequential logic.


Concept / Approach:
Violating timing (e.g., setup/hold) causes metastability or sampling errors. Propagation delay and skew budgets ensure signals settle before capture. Thus, “precise timing is not important” is incorrect; timing closure is a core design activity.

Step-by-Step Solution:

1) Identify sequential boundaries (flip-flops, latches) and relevant timing specs.2) Compute path delays, including combinational delay and clock skew/jitter.3) Ensure constraints: data_arrival_time < clock_edge - setup and data_hold_time >= hold requirement.


Verification / Alternative check:

Static timing analysis (STA) tools flag violations; lab measurements show failures when timing margins are exceeded.


Why Other Options Are Wrong:

Correct: Opposite of reality—timing precision is central.True only for asynchronous circuits: Asynchronous also depends on bounded/relative timing.True only below 1 kHz: Frequency does not remove the need to meet device timing specs.


Common Pitfalls:

Assuming binary levels alone guarantee correctness.Ignoring clock domain crossing (CDC) requirements.


Final Answer:

Incorrect

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