Tutorial - Creating Device Symbols

This tutorial will show you how to use the symbol editor tool to create your own device symbols.

Creating a New Library
Symbol library files hold collections of device symbols along with associated pin function information, default attribute values, and internal-circuit definitions. A single library can contain from one to thousands of part definitions, as suits your application.

Creating a Device Symbol
Device Editor

The symbol editor window contains a drawing area for your symbol, plus a toolbar and a Pin Name List. The toolbar includes standard drawing tools as well as special items for normal and bus  pin placement.

Setting Pin Name Visibility

By default, the symbol editor displays the name of each pin next to the pin stub. For this example, we want to turn this off. To do this:
Setting items in the Properties command with no objects selected sets the default properties when future objects are created.

Drawing the Symbol
The position of the symbol in this window is not important.

Placing Pins
Inverter Symbol in Device Editor
Note: The crossbar portion of the pin tool appears only during placement and dragging, for alignment purposes.

Entering Pin Names and Numbers

Placing the pin graphics on the symbol causes pin names to be added automatically to the pin list. In this section, we will enter more meaningful names and add pin numbers.
Pin Name Editing
Device Editor Save Dialog
Placed LM741

Autocreating a Symbol

For standard types of rectangular symbols, the Autocreate feature will generate a symbol for you in seconds.
Auto Create Symbol
The entry D7..0 will generate a set of eight pins named D7, D6,etc. (9..2) refers to the corresponding pin numbers. The three commas indicate that we want extra space between these pins. Finally, CLK(1) creates a single pin called CLK with pin number 1. The pin numbers can be omitted , if desired.
The autogenerated symbol should now display the pins and pin numbers entered previously.
Autocreated ALS 374
These items can be edited using the drawing tools and Pin Info box, if desired.
The symbol can now be placed in a schematic in the usual manner.