Skip to question

Q152FreeDesign Verification

Interrupt Pulse Is Missing

Difficulty
Easy
Topic
Waveform Debugging
Language
SV
Interview prompt

Question

Each column shows one rising clock edge. req is a one-cycle interrupt request, and ack is the interrupt block's registered notification. While irq_enable is 1, each req pulse must produce exactly one ack pulse on the next sampled edge. Which event-response assertion fails in this waveform?

Waveform for Interrupt Pulse Is Missing. Signals: req, ack, irq_enable. Numbered markers identify sampled columns.
Read the sampled columns from left to right, then test each choice against the stated timing rule.
Choose one

Answer choices

  1. A. ack must be high before req.
  2. B. req must stay high until ack arrives.
  3. C. ack must be high on every idle edge.
  4. D. An enabled req pulse must produce ack on the next edge.
Continue practicing
Q060 · Waveform DebuggingSticky Interrupt Does Not ClearEasyQ1048 · Waveform DebuggingClearing an Interrupt Snapshot Erases Newer EventsMediumPQ084 · Reference ModelsPriority Interrupt Controller Reference ModelHardQ095 · Data StructuresBuild an interrupt-safe sliding-maximum telemetry filterHardQ306 · FirmwareInterrupt or polling for a rare eventEasyP