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Hardware interview practice

Find an associative-array value without a sentinel

MediumSystemVerilog Data StructuresSystemVerilog

A reference model stores int values at byte keys, and every byte value including 8'hFF is legal. Return a success flag separately from the first key whose value matches a target.

Starting point

Question code

int mem[byte];

function bit find_value(input int target, output byte key);
Reviewed example

Work through one case

Input
mem = '{8'hFF: 3}, target = 3
Expected output
success = 1, key = 8'hFF

The all-ones key remains representable because success is carried independently rather than encoded as an impossible byte value.

What to cover

Requirements

  1. Return failure cleanly for an empty associative array.
  2. Visit each existing key at most once using first() and next().
  3. Return the first matching key in associative index order.
  4. Use the function result as the success indicator instead of reserving a key as a sentinel.
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