pin-net-conflict

Remedy ¶

Fix the source netlist so the pin appears in exactly one net, then re-export. The ambiguity is in the input, so nothing downstream can resolve it.

What it means ¶

One (component, pin) appears in the connection lists of two or more nets. A net is the equivalence class of electrically joined pins, so membership is many-pins-to-one-net by definition; multiple membership is malformed input from a reader bug or a corrupt export rather than a design error a person drew.

Why engineers want it ¶

They should rarely see it. It exists as the integrity tripwire behind every per-pin net question the engine answers (pin.role consumers, diff keys, viewer highlights): when the invariant breaks, this fires instead of every downstream answer silently becoming arbitrary. PinNetName documents that it reports the first net in design order; this rule is why that arbitrary pick is safe. A firing points at the READ, not the design: its first corpus run surfaced two reader gaps (unannotated placeholder refs merged, WS1-024; duplicate port designators collapsed, WS1-025).

Impact ¶

Without the tripwire, an inconsistent netlist degrades every derived answer quietly. With it, the file is flagged at check time with the claiming nets named.

Severity is info, deliberately ¶

Both known producers of this state are reader gaps (WS1-024, WS1-025), so today a firing points at the tool’s read of the file, not at the design, and flagging it louder would blame the engineer for our keying. Revisit via severity configuration (WS3-006) once the reader fixes land and a firing is anomalous again.

Two deliberate suppressions ¶

A duplicated ref-des produces this state mechanically, since each colliding placement brings its own copper, so their shared (ref, pin) key lands in several nets. That root cause is duplicate-ref-des’s finding; pins of collided ref-des are skipped here so one authoring slip yields one finding, not two. (Found on the sheetnav conformance fixture the moment this rule first ran: the tripwire works, it just caught prey that already had an owner.)

The second is an UNANNOTATED ref-des: R?, C?, REF**, or a partly-assigned C?1845. This rule asserts something about a PIN, and (R?, 1) does not name one: on one export 176 distinct un-annotated resistors shared that key, so the index saw a single pin sitting on 129 nets and 77% of this rule’s findings on that design described a netlist that was fine. The design is not malformed; the key is not a key. Declining to assert uniqueness over a non-identity is not the same as hiding a defect, and the un-annotated parts are a finding in their own right rather than a silence.

Query structure ¶

report each conflict the model collected.

select P in pin_net_conflicts
  where not ref_des_collided(P) and not ref_des_unannotated(P)

Reads: pin.on_net, ref_des_collision (the suppressions). Tier P.