Nextpnr Integration

Supported Families

PNR_FAMILIES in nextpnr-types.ts maps a synthesisTarget to the nextpnr binary and device list used for place & route. Only targets present in that map support P&R:

The Place & Route command picks the family from the configured synthesisTarget and prompts for a device from that family’s list — it is not ECP5-only. Targets with no entry above (generic, xilinx, quicklogic, sf2) can be synthesized but not placed and routed; the command reports this and stops.

Nexus and MachXO2 are deliberately unsupported. Their nextpnr binaries take different output and constraint flags (--fasm, --pdc) that buildNextpnrArgs does not emit, so listing them would be misleading. They can be re-added once argument handling covers them.

ECP5 Devices

Known packages: CABGA256, CABGA381, CABGA554, CABGA756, CSFBGA285, CSFBGA381, CSFBGA554. Speed grades: 6, 7, 8 (lower is faster).

The package picker is not hard-coded — NextpnrRunner.getValidPackages() probes the nextpnr binary for the packages the chosen device actually supports, and the prompt is skipped entirely when it reports none.

iCE40 Devices

Gowin Devices

Gowin goes through nextpnr-himbaechel, which needs both a device string and a family= value passed via --vopt:

Command-Line Arguments

NextpnrRunner.buildNextpnrArgs() constructs:

nextpnr-ecp5 \
  --json design.json \
  --textcfg output.config \
  --25k \
  --package CABGA381 \
  --speed 6 \
  --freq 50 \              # top entity's clock domain, when it has one
  --lpf constraints.lpf    # when provided