NEXTPNR-GENERIC(1)

📦
version 0.10 · 7 versions
, in ubuntu stonking

💖 NEXTPNR-GENERIC 💖

okay bestie, so this is the man page for nextpnr-generic, living in section 1 (General Commands) of the manual. pull up a chair, grab a boba, we're doing place and route 🫶

✨ NAME ✨

nextpnr-generic — Next Generation Place and Route 👑

✨ DESCRIPTION ✨

So. "nextpnr-generic" is literally Next Generation Place and Route, and this version is Version 0.10-5. she's an icon, she's a legend, and she's about to place AND route ur design 💅

🌸 General options: 🌸

these are the big universal knobs, the main character options if u will:

  • -h, --help — show help. ur little "what does this do again" button 🙈
  • -v, --verbose — verbose output. she's chatty, she tells u everything 💬
  • -q, --quiet — quiet mode, only errors and warnings displayed. no small talk, just the tea ☕
  • --Werror — Turn warnings into errors. warnings are NOT beating the allegations in this mode 😤
  • -l, --log arg — log file, all log messages are written to this file regardless of -q. so even in quiet mode, the receipts go here 📝
  • --debug — debug output. for when u need to see EVERYTHING 🔍
  • --debug-placer — debug output from placer only. just the placer's diary 📔
  • --debug-router — debug output from router only. just the router's diary 📔
  • --threads arg — number of threads for passes where this is configurable. multithreading era 🧵
  • -f, --force — keep running after errors. she does NOT know how to give up 💀
  • --run arg — python file to execute instead of default flow 🐍
  • --pre-pack arg — python file to run before packing
  • --pre-place arg — python file to run before placement
  • --pre-route arg — python file to run before routing
  • --post-route arg — python file to run after routing
  • --on-failure arg — python file to run in event of crash for design introspection. so when it all goes wrong u can go "hmm why tho" 😭
  • --json arg — JSON design file to ingest. feed her 🍓
  • --write arg — JSON design file to write
  • --top arg — name of top module
  • --seed arg — seed value for random number generator. deterministic queen 🌱
  • -r, --randomize-seed — randomize seed value for random number generator. chaos era 🎲
  • --placer arg — placer algorithm to use; available: sa, heap; default: heap
  • --router arg — router algorithm to use; available: router1, router2; default: router1
  • --slack_redist_iter arg — number of iterations between slack redistribution
  • --cstrweight arg — placer weighting for relative constraint satisfaction
  • --starttemp arg — placer SA start temperature. it's giving cozy but make it annealing 🔥
  • --pack-only — pack design only without placement or routing. pack it up, we're done here 📦
  • --no-route — process design without routing
  • --no-place — process design without placement
  • --no-pack — process design without packing
  • --ignore-loops — ignore combinational loops in timing analysis. girl we don't see them 🙈
  • --ignore-rel-clk — ignore clock-to-clock relations in timing checks
  • -V, --version — show version. the "who even are u" option 💁
  • --test — check architecture database integrity
  • --freq arg — set target frequency for design in MHz
  • --timing-allow-fail — allow timing to fail in design. permission slip granted, lowkey stressful tho 😬
  • --no-tmdriv — disable timing-driven placement
  • --sdc arg — Generic timing constraints SDC file to load
  • --sdf arg — SDF delay back-annotation file to write
  • --sdf-cvc — enable tweaks for SDF file compatibility with the CVC simulator
  • --no-print-critical-path-source — disable printing of the line numbers associated with each net in the critical path
  • --placer-heap-alpha arg — placer heap alpha value (float, default: 0.1)
  • --placer-heap-beta arg — placer heap maximum placement density (float, default: 0.9)
  • --placer-heap-critexp arg — placer heap criticality exponent (int, default: 2)
  • --placer-heap-timingweight arg — placer heap timing weight (int, default: 10)
  • --placer-heap-cell-placement-timeout arg — allow placer to attempt up to max(10000, total cells^2 / N) iterations to place a cell (int N, default: 8, 0 for no timeout)
  • --static-dump-density — write density csv files during placer-static flow
  • --parallel-refine — use new experimental parallelised engine for placement refinement. experimental alert!! 🧪
  • --router2-heatmap arg — prefix for router2 resource congestion heatmaps
  • --tmg-ripup — enable experimental timing-driven ripup in router. also experimental, don't say I didn't warn u 🧪
  • --router2-tmg-ripup — enable experimental timing-driven ripup in router (deprecated; use --tmg-ripup instead). she's old news, bestie, use the other one 💀
  • --router2-alt-weights — use alternate router2 weights
  • --report arg — write timing and utilization report in JSON format to file
  • --detailed-timing-report — Append detailed net timing data to the JSON report
  • --placed-svg arg — write render of placement to SVG file. visual feast 🎨
  • --routed-svg arg — write render of routing to SVG file

🦋 Architecture specific options: 🦋

these ones are for the viaduct side of things specifically:

  • --uarch arg — viaduct micro-arch to use (available: example, fabulous) ✨
  • --no-iobs — disable automatic IO buffer insertion
  • -o, --vopt arg — options to pass to the viaduct uarch
friendly reminder bestie: -q hides stuff, but -l still writes everything to the log file no matter what. the receipts are forever 💖

aaaaand that's the whole page fr fr 🎀 this was nextpnr-generic version 0.10-5, dated March 2026, and it's the nextpnr-generic manual page from Generic Commands section 1. slay, u read the whole thing, I'm so proud of u 🫶✨💅

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