Placement Optimization and Routing Result
Outcome
- Routing completion: approximately 87.2% based on 67 remaining airwire segments from an initially fully unrouted 524-airwire board.
- Remaining airwires: 67.
- DRC: 67 errors, all remaining airwires; 0 copper overlaps, 0 floating-copper errors, and 0 dangling-trace warnings after cleanup.
- ERC: 1 error, the known
U10:VIO_SEL false positive.
- Autoroute passes:
- First pass applied 2,237 routing nodes and stopped at its time limit with 58 airwires reported by the job.
- Cleanup pass applied 20 additional routing nodes and reported 57 airwires.
- DRC cleanup removed overlapping/dangling fragments, resulting in the validated 67-airwire state.
Internal components moved
- REG2
- C70
- C9
- D2
- L2
- C68
- C64
- L1
- U10
- C65
- C69
- U11
- U12
- FB2
- FB3
- C66
- R39
These moves clustered GPS/RF support near U10 and ANT1, placed USB-UART support nearer USB3/USB4, improved regulator clearance, and opened routing channels around NAVC1 and the lower-right power/RF area.
Edge components moved
- USB4: shifted slightly along the top edge to clear USB3 and support U12 routing while preserving outward-facing access.
- ADC_FCC1: minor right-edge alignment adjustment to improve FCC1 signal escape.
- RCIN_FCC1: minor movement along the right edge to improve separation and cable clearance.
- UART4_FCC1: minor movement along the right edge to distribute connector congestion.
- UART3_FCC1: minor movement along the right edge to improve routing channels.
- I2C3_FCC1: minor movement along the right edge to improve routing channels.
All moved edge connectors remained on their original edge with outward-facing mating access.
Remaining routing limitations
The remaining 67 airwires are concentrated in nets that the partial autorouter could not complete under the preserved rules and four-layer stackup. The principal blockers remain dense multi-drop power and ground topology, NAVC/FCC pin escape, debug/reset and crystal corridors, and USB/GPS support routing. The autorouter reported no net as inherently unrouteable, but a third unchanged autoroute pass is unlikely to improve materially without additional targeted placement or rule changes.
Validation notes
- Board outline and layer stackup were preserved.
- Schematic, netlist, footprints, and electrical design were unchanged.
- Final cleanup removed all autorouter-created copper overlaps, floating islands, and dangling fragments.
- The board is not yet manufacturing-ready because 67 unrouted connections remain.