DRC

DRC (design-rule check) is a program that measures a drawing against the factory’s geometry laws and writes a list of places that break them.

The orange mark sits in the tight gap. The two straps are still there under the mark.

The factory will not debate intent. Minimum width, spacing, enclosure, density, antenna, and notch rules are the contract. DRC is a spellchecker. It does not know whether the circuit is wise. It knows whether a 0.12 micrometer wire appeared on a 0.14 micrometer layer. The result is a dock of errors: M1.S.1 14207 violations, each one clickable. Zoom to a pair of corners that sneak within 0.13 micrometer. Green is not a passing grade until the count is zero, or until a waiver is written down. The rules come from a foundry or a board house, often inside a PDK, and the editor runs them. A cousin check that compares the drawing to a schematic is LVS. Passing DRC and failing LVS is a pretty, wrong chip. A clean DRC does not mean the part will work. Yield, models, and the schematic still exist. Another miss is running last year’s deck on this year’s process.

When a full deck takes hours, run DRC in pieces: width and spacing first, then density, then antenna. A merge on a power mesh can collapse 14,000 errors to 12. Do not disable a rule because it is noisy. Fix the geometry, or file a waiver with a reason. A waiver is a document, not a habit.

Why the laws bind, why the check is only a spellchecker, and how width and space are measured are covered in design rules and DRC and width and space.