University
of Rhode Island Department of Electrical and Computer Engineering
University
of Rhode Island
Department of Electrical and Computer Engineering
Section 4: Mentor Graphics Accusim Tutorial
Accusim is a spice-like circuit analysis tool. This section of the tutorial will demonstrate how to use Accusim to perform a transient analysis of the inverter.
1) Set up the default models in the schematic sheet
- Use Design Architect (DA) to open the schematic sheet that you created in Section 1: Design Architect.
- Right click on the pnp transistor, and choose Properties > Modify Multiple.
- Initially, the value of the ASIM_MODEL property is blank. Change the value to "mp4lv" as shown here. This property specifies the name of the spice model to use for the device.
- In a like manner, change the value of the ASIM_MODEL property of the npn transistor to "mn4lv".
2) Copy the model library
- In the ~/inv container directory, create a new directory called asim_lib.
- Now copy the ps3.model.lib file into the asim_lib directory. The ps3.model.lib file contains the spice models for the two transistors.
When Accusim starts, it will automatically read the contents of any .lib files that are found in the asim_lib directory.
3) Invoke Accusim
Using Design Manager, browse to the ~/inv directory. Right click on the Design Viewpoint that you created with DVE (it is probably called "default"). Choose Open>Accusim on the menu that appears. The Accusim window will appear as shown below.
4) Set up and Run the Transient Analysis
- Switch to Transient Analysis by clicking the "Time Mode" button on the Palette. A dialog box will appear. Enter "1p" in the "Time Step" box, and enter "10n" in the "Stop Time" box. Click OK.
- Use the Add > Keeps menu item and "Add All" keeps in the dialog box that appears.
- Use the "Add Force" button to add a DC force of 10 Volts to the VCC input on the inverter. The Add Force dialog box and parameters can be seen here.
- Similarly, create a pulse force on the IN input port. The dialog box and parameters for the pulse force can be seen here.
- In the Schematic Sheet window, use the mouse to select both the IN and OUT ports of the inverter. Now Click the "Trace" button on the Palette to create a trace window for the two signals.
- Finally, click the RUN button on the Palette. When the run is finished, the trace window should look like the image below:
5) Print the Trace to a File
You cannot print the trace directly to the printer, it must be saved to a file first.
Use the File > Print > Active Window menu item to open the print dialog box.
Click the "Export Graphic" Button, and choose "EPS (Encapsulated Postscript)" as shown below.
Enter a path and a name for the file; Accusim will automatically add the .eps extension.
Click OK.
Use the lp, or the lpr command to send the file to the printer.
Congratulations! You have reached the end of the Tutorial.
Mentor Graphics Tutorial Home Page
created by Seth Milman, 7/16/98
last update: 7/16/98
