ICC2: 11. Detailed route Cheat Sheet

This stage covers detailed routing: confirming route readiness, running route_auto, checking DRC, antenna and connectivity, repairing remaining violations, adding redundant vias, reviewing routing statistics and shape clean-up, and signoff DRC.

Sanity check cheat sheet

One row per command card. Read left to right: the check, the command that answers it, then what a healthy result, a result to review and a hard stop look like.

Card	Check and when	Command	Healthy	Review	Hard stop
D-01	Route readiness Before route_auto	`check_routability` `check_legality`	Both checks are clean, and the global route congestion is within budget.	Optional checks not run, or findings on cells that cannot move.	Illegal placement, blocked pins on many instances, or unrouted power nets.
D-02	Route run and log After D-01	`route_auto`	The run ends with no errors, and DRC violation counts fall over the iterations.	A few violations remain, or warnings about nets skipped or frozen.	Any error message, or a violation count that stops falling.
D-03	DRC, open and antenna check After D-02	`check_routes` `check_routes -antenna true`	No spacing, area, width, open net or antenna violations remain.	A few violations on frozen nets or layers beyond the default report cap.	Open nets, shorts, or violations beyond what your signoff will accept.
D-04	Connectivity and shorts After D-02	`check_lvs` `check_lvs -checks open`	No shorts, opens or floating shapes on signal, clock and power nets.	Power terminals treated as unconnected sources, which inflates open counts.	Any short, or an open on a net that must connect.
D-05	Repair remaining violations After D-03	`route_detail -incremental true -initial_drc_from_input true` `route_eco -nets {<nets>} -reroute modified_nets_only`	The count falls to zero and check_routes is rerun clean.	Count falls but moves to new nets or layers, which suggests a congestion cause.	A count that rises after repair, or open nets left (incremental routing does not fix opens).
D-06	Redundant vias After D-03	`add_redundant_vias` `add_redundant_vias -list_only true`	The conversion rate meets the project target and DRC is still clean afterwards.	Rate below target on a few layers where the mapping table has no entry.	New DRC violations from insertion, or timing lost on nets that were to be preserved.
D-07	Routing statistics After D-02	`report_design -routing` `report_wirelength`	Wire length and via counts per layer match the plan and earlier runs.	Wire length or via count well above the global route estimate on some layers.	Wire on layers outside the planned range.
D-08	Shape clean-up After D-03	`remove_redundant_shapes` `optimize_routes`	Dangling and floating shapes are removed, and check_routes is rerun clean.	Nets skipped because they are open or have violations.	Clean-up run while open nets or violations remain unexplained.
D-09	Signoff DRC After D-03	`signoff_check_drc` `signoff_fix_drc`	Signoff DRC reports no violations, or only waived ones, in the final run.	Rules above the per-rule fix limit, or fixing limited to top-level violations.	Violations remaining after the repair loops, or new ones introduced by fixing.

Command cheat sheet

ICC2 commands. Angle brackets are placeholders, and values shown are examples, not project limits. A dagger (†) marks a command the notes behind this book do not fully cover; it is shown without options, so confirm it with man or help in your release.

Route
`route_auto`	Automatic full routing. Changes the design.
`route_detail`	Detail routing step. Changes the design.
`route_detail -incremental true -initial_drc_from_input true`	Incremental detail route that starts from stored check_routes results. Changes the design.
`route_eco -nets {<nets>} -reroute modified_nets_only`	ECO routing for chosen nets. Changes the design.
`route_track`	Track assignment step. Changes the design.
Verify routing
`check_routes`	DRC, open net, antenna and voltage-area checks on routed signal nets. Writes zroute.err.
`check_routes -antenna true`	Includes the antenna check.
`check_routes -nets {<nets>}`	Restricts the check to chosen nets.
`check_lvs`	Shorted nets, open nets and floating shapes.
`check_lvs -checks open`	Only the open net check.
Error data
`write_drc_error_data -error_data <name> -file_name <file>`	Exports DRC error data to a file. Writes a file.
`open_drc_error_data -file_name <file>`	Opens saved error data for review.
`get_drc_errors -error_data <name>`	The errors in an error data set.
`get_drc_error_types -error_data <name>`	The violation types in an error data set.
Vias and clean-up
`add_redundant_vias`	Postroute redundant via insertion. Changes the design.
`add_redundant_vias -list_only true`	Shows the via mapping table without inserting.
`report_via_mapping`	The via mapping table.
`remove_redundant_shapes`	Removes dangling and floating shapes. Changes the design.
`optimize_routes`	Wire length and via count optimisation after routing. Changes the design.
Signoff DRC and statistics
`signoff_check_drc`	Runs signoff DRC and writes signoff_check_drc.err.
`signoff_fix_drc`	Fixes signoff DRC violations and writes a summary report. Changes the design.
`report_design -routing`	Wiring and via statistics.
`report_wirelength`	Wire length per layer and direction.