Editing Netlist (section)

==Contents and structure of a netlist==
Most netlists either contain or refer to descriptions of the parts or devices used. Each time a part is used in a netlist, this is called an "instance".

These descriptions will usually list the connections that are made to that kind of device, and some basic properties of that device.  These connection points are called "terminals" or "pins", among several other names.

An "instance" could be anything from a [[MOSFET]] transistor or a [[bipolar junction transistor]], to a [[resistor]], a [[capacitor]], or an [[integrated circuit]] chip.

Instances have "terminals". In the case of a vacuum cleaner, these terminals would be the three metal prongs in the plug. Each terminal has a name, and in continuing the vacuum cleaner example, they might be "Neutral", "Live" and "Ground". Usually, each instance will have a unique name, so that if you have two instances of vacuum cleaners, one might be "vac1" and the other "vac2". Besides their names, they might otherwise be identical.

Networks (nets) are the "wires" that connect things together in the circuit. There may or may not be any special attributes associated with the nets in a design, depending on the particular language the netlist is written in, and that language's features.

Instance based netlists usually provide a list of the instances used in a design.
Along with each instance, either an ordered list of net names is provided, or a list of pairs provided, of an instance port name, along with the net name to which that port is connected. In this kind of description, the list of nets can be gathered from the connection lists, and there is no place to associate particular attributes with the nets themselves.  [[SPICE]] is an example of instance-based netlists.

Net-based netlists usually describe all the instances and their attributes, then describe each net, and say which port they are connected on each instance. This allows for attributes to be associated with nets.
[[EDIF]] is probably the most famous of the net-based netlists.