NAME

       nextpnr-ice40 - Next Generation Place and Route

DESCRIPTION

       "nextpnr-ice40" -- Next Generation Place and Route (Version 0.7-1)

   General options:
       -h [ --help ]
              show help

       -v [ --verbose ]
              verbose output

       -q [ --quiet ]
              quiet mode, only errors and warnings displayed

       --Werror
              Turn warnings into errors

       -l [ --log ] arg
              log file, all log messages are written to this file regardless of -q

       --debug
              debug output

       --debug-placer
              debug output from placer only

       --debug-router
              debug output from router only

       --threads arg
              number of threads for passes where this is configurable

       -f [ --force ]
              keep running after errors

       --gui  start gui

       --gui-no-aa
              disable anti aliasing (use together with --gui option)

       --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

       --json arg
              JSON design file to ingest

       --write arg
              JSON design file to write

       --top arg
              name of top module

       --seed arg
              seed value for random number generator

       -r [ --randomize-seed ]
              randomize seed value for random number generator

       --placer arg
              placer algorithm to use; available: sa, heap, static; 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

       --pack-only
              pack design only without placement or routing

       --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

       --ignore-rel-clk
              ignore clock-to-clock relations in timing checks

       -V [ --version ]
              show version

       --test check architecture database integrity

       --freq arg
              set target frequency for design in MHz

       --timing-allow-fail
              allow timing to fail in design

       --no-tmdriv
              disable timing-driven placement

       --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 beta value (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)

       --parallel-refine
              use new experimental parallelised engine for placement refinement

       --router2-heatmap arg
              prefix for router2 resource congestion heatmaps

       --tmg-ripup
              enable experimental timing-driven ripup in router

       --router2-tmg-ripup
              enable experimental timing-driven ripup  in  router  (deprecated;  use  --tmg-ripup
              instead)

       --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

       --routed-svg arg
              write render of routing to SVG file

   Architecture specific options:
       --package arg
              set device package

       --pcf arg
              PCF constraints file to ingest

       --asc arg
              asc bitstream file to write

       --read arg
              asc bitstream file to read

       --promote-logic
              enable promotion of 'logic' globals (in addition to clk/ce/sr by default)

       --no-promote-globals
              disable all global promotion

       --opt-timing
              run post-placement timing optimisation pass (experimental)

       --tmfuzz
              run path delay estimate fuzzer

       --pcf-allow-unconstrained
              don't require PCF to constrain all IO