Creating Device Symbols and Libraries
Creating a New Library
- Right-click on the Parts palette’s parts list and select the “New Lib” command from the pop-up menu.
- Create a new library called “MyLib.clf” in the Libs directory.
Device library files hold collections of part symbols along with associated pin function information, default attribute values and external circuit references. A single library can contain from one to thousands of part definitions, to suit your needs.
Creating a Device Symbol
- Select New from the File menu
- In the “New” dialog select “Device Symbol”.
The Device Editor window contains a drawing area for your symbol, a tool palette and a pin list. The tool palette includes standard drawing tools plus special items for normal, inverted and bus pin placement.
- Click on the polygon (
) tool in the tool palette. - Draw a symbol similar to the one shown (Note: double click on the last point to terminate polygon drawing).
) tool in the tool palette.
- Select the (
) pin tool. - Place input pins on the symbol by clicking at the positions shown.
- Select the (
) pin tool. - Place an output pin as shown.
) pin tool.
) pin tool.
Note: The crossbar portion of the T pin tool only appears during placement and dragging for alignment purposes
- Return to the pointer (
) tool. - Select the Part Attributes command from the Options menu. (Note: there will be no attributes in the list if there is no active design).
- Select the Part field in the list.
- Enter the value “LM741”.
- Select the Package field in the list.
- Enter the value “NAT8DPN” or other package code.
- Click the Done button.
) tool.
These attribute values will appear as the defaults when this part is used on a schematic. If desired, these values can be overridden for each individual device.
Entering Pin Names and Numbers
- Double Click on the PIN1 item in the pin list and then type in the name “INA”.
- Click in the “Pin Number” text box and enter 2
- Double Click on the PIN2 item in the pin list and then type in the name “INB”.
- Click in the “Pin Number” text box and enter 3
- Double Click on the PIN3 item in the pin list and then type in the name “OUT”.
- Click in the “Pin Number” text box and enter 6
- Select “Output” in the Pin Function drop-down menu.
We have now entered default values for the pin numbers. These can be edited on the schematic for individual pins, if desired.
Saving and Using the Part
- Select the Save As command from the File menu.
- Enter the part name “LM741” or any other desired name.
- Click on the “MyLib.clf” library in the list to select a destination and press “Save”.
- Close the Device Editor.
If it is not already selected, select the “MyLib.clf” library in the drop-down library list in the Parts palette.
- If it is not already selected, select the “MyLib.clf” library in the drop-down library list in the Parts palette.
- Double-click on the newly-created part and place one in the schematic.
Auto-Creating a Symbol
For standard types of rectangular symbols, the Auto Create feature will generate a symbol for you in seconds.
- Select New from the File menu.
- In the “New” dialog select “Device Symbol”.
- Select the “Auto Create Symbol” command from the Options menu.
- In the Name box, enter “ALS374”, or any other desired symbol name.
- In the “Left Pins” box, enter the text “D7..0(9..2),,,CLK(1)”.
“D7..0” will generate a set of 8 pins named D7, D6, etc. “(9..2)” are the corresponding pin numbers. The three commas indicate that we want extra space between these pins. “CLK(1)” creates a single pin called CLK with pin number 1. The pin numbers can be omitted, if desired.
- In the “Right Pins” box, enter the text “Q7..0(12..19)”.
- Click on the Generate button.
The auto-generated symbol should now display the pins and pin numbers entered above. These items can be edited using the drawing tools and Pin Info dialog, if desired.
- Select the Save Part As item in the file menu and save the new part to the “MyLib.clf” library.
- Close the Device Editor window.
This completes the tutorial section “Device Symbol Editing”.