ERC

Function

Electrical Rule Check.

Syntax

ERC

This command is used to test schematics for electrical errors. The summary is written into a text file with the extension .erc.

The following warning messages may be generated:

• SUPPLY Pin Pin_Name overwritten with Net_Name
• NC Pin Elem._Name Pin_Name connected to Net_Name
• POWER Pin El._Name Pin_N. connected to Net_Name
• only one Pin on net Net_Name
• no Pins on net Net_Name
• unconnected Pin: Element_N. Pin_N.
• Junction at (x, y) appears to connect nets Net_Name and Net_Name
• NET Net_Name: missing Junction at (x, y)
• NET Net_Name: close but unconnected wires at (x, y)
• NETS Net_Name and Net_Name too close at (x, y)
• NET Net_Name: wire overlaps pin at (x, y)
• pins overlap at (x, y)

• no SUPPLY for POWER Pin Element_Name Pin_Name
• no SUPPLY for implicit POWER Pin El._Name Pin_Name
• unconnected INPUT Pin: Element_Name Pin_Name
• only INPUT Pins on net Net_Name
• OUTPUT and OC Pins mixed on net Net_Name
• n OUTPUT Pins on net Net_Name
• OUTPUT and SUPPLY Pins mixed on net OUTNET
• uninvoked MUST gate Gate_Name in part Part_Name (Device_Name)
• SUPPLY Pin Pin_Name overwritten with more than one signal (Net_Name, ...)

Consistency Check

The ERC command also performs a Consistency Check between a schematic and its corresponding board, provided the board file has been loaded before starting the ERC. As a result of this check the automatic Forward&Back Annotation will be turned on or off, depending on whether the files have been found to be consistent or not.

Please note that the ERC detects inconsistencies between the implicit power and supply pins in the schematic and the actual signal connections in the board. Such inconsistencies can occur if the supply pin configuration is modified after the board has been created with the BOARD command. Since the power pins are only connected "implicitly", these changes can't always be forward annotated
. If such errors are detected, Forward&Back Annotation will still be performed, but the supply pin configuration should be checked!