unspecified-pin-with-driver

Remedy ¶

Set the pin’s electrical type in the symbol to what the datasheet says it is. Fixing the symbol is the remedy, because suppressing the finding leaves the ERC blind on every board that uses it.

What it means ¶

A net has at least one hard driver (output / power-out pin, including a power symbol’s virtual pin), and one of its other member pins declares no electrical type at all.

Why engineers want it ¶

It is the “unspecified” column of the ERC connection matrix (KiCad warns on unspecified against everything). An untyped pin is a library gap, since the matrix cannot say whether the pairing is legal. The gap matters most on a driven net, where the untyped pin might itself be a fighting driver or a supply pin shorted to a signal.

Impact ¶

If the untyped pin turns out to be an output, this is an output-output-conflict that the matrix could not see. If it is a supply pin, this is a rail-to-signal short. Fixing the symbol (typing the pin) either clears the warning or upgrades it to the real error.

Scope note ¶

“Unspecified” means the symbol DECLARES the pin and types it as nothing. A KiCad passive pin is typed and never fires this. That false positive, a resistor on every driven net, kept this row out of the catalog until PASSIVE entered the direction vocabulary. Sometimes the read never saw a symbol for a pin (a board footprint’s pads, a sub-sheet component in a root-only hierarchy read). That is a read gap, not an authoring gap, and the rule skips the pin via pin.declared. The rule is gated on a driver being present. A wholly untyped read (a bare EDIF netlist with no direction data) has no drivers in evidence, so the rule reports nothing on it by construction. Cross-sheet (external) nets are skipped. Virtual power-symbol pins carry power types by construction and are excluded as subjects.

Query structure ¶

select the driven nets carrying a declared-but-untyped real pin.

select N in nets where count(distinct component(P) : P in N, hard_driver(P)) >= 1
  and exists P in N.connections
    where pin_dir(P) == unspecified and declared(P) and not virtual(P)

Reads: net.attributes, on_net, pin.electrical_type. Tier R.