Component Syntax

The component section begins with the keyword COMPONENT. Each component begins with the keyword COMP.

COMPONENTS                         begin component section
COMP                               begin component
REFDES <ref_designator>            reference designator
CLASS <class i.e. IC,DIE,PASSIVE>  properties (if known)
NAME <name>
DEVICE <device_name>
VALUE <value>
PART_NAME <part_name>
PINS <number of pins>              enumeration of pins
PIN <pin_num> <x> <y> <net (index to NET TABLE)>
PIN 10 108.81 93.65 231
PIN 9 108.81 91.11 321

REFDES - each time a component is placed it is assigned a unique reference designator. This is because a component symbol (such as a chip resistor) might be used 10-100 times in the same circuit. While the basic component does not change, the placement coordinates will be different and the value of the component may be different.

CLASS - this is just an attribute taken from Allegro/APD. Allegro divides components into certain classes such as IC (for a die chip), IO (for a connector or BGA substrate with pins, PASSIVE for a chip resistor, capacitor or inductor. Note: Class names are not always correctly applied within Allegro. We have seen passive components defined as IC or IO.

NAME - a name assigned to this component by Allegro.

DEVICE - a device name assigned to this component

VALUE - a value for this component. It might be empty or it might be appropriate for a capacitor or resistor.

PART_NAME - yet another name; we don't know how this differs from NAME or DEVICE.

PINS - the number of pins for this component

PIN - a specific pin followed by its label, its x,y position and an index to its net.