DescriptionQ905
Q905DesignASIC interview problem
Find the unpaired fault ID
TechniquesXORFramingBackpressure
DifficultyEasy
TopicStreaming RTL
LanguageSystemVerilog
Requirements4 checkpoints
01
Problem
Consume a framed stream in which every fault ID appears exactly twice except one ID that appears once, then return the unpaired ID.
Example input and output
Use this case to check your interpretationInput
accepted fault IDs=[5,2,5,2,7], last asserted with 7Output
result_id=7Explanation
Pairwise IDs cancel under XOR and the final accepted unpaired zero-capable accumulator result is held until consumed.
02
Requirements (4)
- Change the accumulator only when fault_valid and fault_ready are both asserted.
- Include the accepted final item in the result when fault_last is asserted.
- Support an unpaired ID of zero.
- Hold result_id and result_valid stable during result backpressure.