Skip to the selected question
ASIC.FYI

ASIC Question Bank

1,000+ hardware interview questions
Question bank1110 results
  1. Easy
  2. Easy
  3. Medium
  4. Medium
  5. Medium
  6. Medium
  7. Easy
  8. Easy
  9. Easy
  10. Easy
  11. Easy
  12. Easy
  13. Easy
  14. Easy
  15. Medium
  16. Easy
  17. Medium
  18. Easy
  19. Hard
  20. Medium
  21. Medium
  22. Easy
  23. Medium
  24. Medium
  25. Medium
  26. Easy
  27. Medium
  28. Medium
  29. Easy
  30. Easy
  31. Medium
  32. Medium
  33. Hard
  34. Easy
  35. Medium
  36. Hard
  37. Easy
  38. Medium
  39. Hard
  40. Medium
  41. Medium
  42. Easy
  43. Medium
  44. Medium
  45. Medium
  46. Easy
  47. Hard
  48. Easy
  49. Easy
  50. Easy
DescriptionQ477
Page ↗
Q477DVASIC interview problem

Detect X or Z in valid data

TechniquesX propagationFour-state logicChecker
DifficultyEasy
TopicVerification Utilities
LanguageSystemVerilog
Requirements3 checkpoints
01

Problem

Report an error whenever a valid 32-bit data value contains any X or Z bit.

Example input and output

Use this case to check your interpretation
Input
cycle 4: valid=1,data contains bit X; cycle 5: valid=0,data contains bit Z
Output
error at cycle 4 only
Explanation

Four-state detection flags the accepted unknown value, while invalid-cycle payload is deliberately ignored.

02

Requirements (3)

  • Check only when valid is asserted.
  • Detect both X and Z.
  • Use four-state semantics.