1,000+ ASIC Interview Questions: SystemVerilog, UVM & RTL

DescriptionQ284

Page ↗

Q284ArchFollow-up to Q283ASIC interview problem

Return the top K densest pages

TechniquesTop KSortingHistogram

DifficultyMedium

TopicMemory Systems

LanguageSystemVerilog

Requirements4 checkpoints

Problem

Return at most K individual 4 KiB pages ordered from highest to lowest density.

Page-density records entering a descending ordering stage with blank top-K result slots — Density is the primary key and lower page base is the deterministic tie-breaker.

Function headerSystemVerilog

function automatic void densest_top_k_page_4kb(
  input bit [31:0] mem[longint unsigned],
  input int unsigned k,
  output longint unsigned pages[$],
  output int unsigned densities[$]
);

Example input and output

Use this case to check your interpretation

Input

page densities={0x1000:3,0x2000:1,0x3000:3,0x4000:2}; K=3

Output

[(0x1000,3),(0x3000,3),(0x4000,2)]

Explanation

Density sorts descending and the lower page base wins the tie between the two density-three pages.

Requirements (4)

Return min(K, number of populated pages) records.
Order by density descending.
Break equal-density ties by lower page base.
Clear output queues before appending.