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Hardware interview practice

Wait for drain with a deadline

MediumTemporal ChecksSystemVerilog

Wait for all outstanding work and expected transactions to drain, but fail if the deadline expires.

Reviewed example

Work through one case

Input
timeout_cycles=5; outstanding reaches0 at poll2; expected queue becomes empty at poll4
Expected output
wait returns successfully after poll4

Drain requires both conditions simultaneously; completion before the fifth poll avoids the fatal deadline.

What to cover

Requirements

  1. Check both the outstanding counter and expected queue.
  2. Count at most timeout_cycles.
  3. Report a fatal error when either remains non-empty.