Skip to question

Q201FreeDesign Verification

FIFO Full Flag Asserts Late

Difficulty
Easy
Topic
Waveform Debugging
Language
SV
Interview prompt

Question

The FIFO depth is four. occupancy shows the number of entries immediately after each edge, and full is observed with that occupancy. full must be 1 exactly when occupancy is four and 0 when occupancy is below four. Which full-flag assertion fails first?

Waveform for FIFO Full Flag Asserts Late. Signals: push, pop, occupancy, full. 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. push must remain high after the FIFO becomes full.
  2. B. full must rise when occupancy first becomes one.
  3. C. occupancy may never equal the FIFO depth.
  4. D. full must be high whenever occupancy is four.
Continue practicing
Q116 · Waveform DebuggingRead Attempt on an Empty FIFOEasyQ088 · Waveform DebuggingFIFO Count Changes on Simultaneous Push and PopEasyQ024 · Waveform DebuggingFIFO Returns the Wrong Head EntryEasyQ007 · RTL DesignBuild a synchronous FIFO and race-free BFMMediumQ226 · RTL DesignImplement a synchronous FIFO with exact boundary behaviorMediumP