Place and RouteΒΆ This contains information related to the place and route step. Nextpnr models Generated model files bel.txt (legacy, unused) bel.v2.txt bel.v3.txt (BEL timing) Clock arrival time Conditions pips.txt placement_estimate.txt Per-type placement estimates Nextpnr compilation Building User guide Primitive instantiation Constraints for the placement of IO/BELs Pin Constraints File (PCF) How it works PCF syntax What the BEL letter means Finding valid I/O locations Running the flow Worked example Troubleshooting