nextpnr-ecp5 -- Next Generation Place and Route (git sha1 4c73061)

General options:
  -h [ --help ]               show help
  -v [ --verbose ]            verbose output
  -q [ --quiet ]              quiet mode, only errors and warnings displayed
  -l [ --log ] arg            log file, all log messages are written to this
                              file regardless of -q
  --debug                     debug output
  -f [ --force ]              keep running after errors
  --gui                       start gui
  --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
  --json arg                  JSON design file to ingest
  --seed arg                  seed value for random number generator
  -r [ --randomize-seed ]     randomize seed value for random number generator
  --slack_redist_iter arg     number of iterations between slack redistribution
  --cstrweight arg            placer weighting for relative constraint
                              satisfaction
  --pack-only                 pack design only without placement or routing
  --ignore-loops              ignore combinational loops in timing analysis
  -V [ --version ]            show version
  --test                      check architecture database integrity
  --freq arg                  set target frequency for design in MHz
  --no-tmdriv                 disable timing-driven placement
  --save arg                  project file to write
  --load arg                  project file to read

Architecture specific options:
  --25k                       set device type to LFE5U-25F
  --45k                       set device type to LFE5U-45F
  --85k                       set device type to LFE5U-85F
  --um-25k                    set device type to LFE5UM-25F
  --um-45k                    set device type to LFE5UM-45F
  --um-85k                    set device type to LFE5UM-85F
  --um5g-25k                  set device type to LFE5UM5G-25F
  --um5g-45k                  set device type to LFE5UM5G-45F
  --um5g-85k                  set device type to LFE5UM5G-85F
  --package arg               select device package (defaults to CABGA381)
  --speed arg                 select device speedgrade (6, 7 or 8)
  --basecfg arg               base chip configuration in Trellis text format
                              (deprecated)
  --override-basecfg arg      base chip configuration in Trellis text format
  --textcfg arg               textual configuration in Trellis format to write
  --lpf arg                   LPF pin constraint file(s)
  --lpf-allow-unconstrained   don't require LPF file(s) to constrain all IO