Using HSPICE effectivly with SUE

This pages describes how to start HSPICE from within a Sue schematic. In addition, NST is used to quickly draw waveforms right out of Sue.
The following describes how to do that by using a standard Nand gate. Both, examples for transient analysis and for dc-analysis are given.

Example 1: Transient Analysis

Enter the following Schematic:

Use the "t" command to enter text. As inputs you can use the "pulse" icon. Doubleclick on it and enter some waveform values. The actual waveforms don't matter too much for now.

Be sure you are in "spice" mode. If necessary do "Sim | Change Simulation Mode..."
Hit "h" to produce a netlist and run it through HSPICE. You can follow the progress in the Sue terminal window
In the end, a "nst" window like the following will come up:

Now you are ready to plot nodes: In Sue, highlight a wire by clicking on it. Then hit "p" to print the net, or "o" to un-print the net. All those commands are also listed under the "Sim" menu in the menubar.

Example 2: DC Analysis

Performing a dc-sweep is not quite as straightforward as a transient analysis. The reason is that nst tries to open a .tr0 file, which is the standard output file for transient anlysis. DC-analysis however defaults to a .sw0 file. In addition, "awaves" seems to handle sweep plots better than "nst".
Therefore, the following procedure is recommended for DC-Analysis:

Enter the schematic as follows:

The battery symbols are called "dc_supply". Double-click on them and give them the shown names and voltages.
In the ".dc" command it is necessary to use "Vvds" since SUE will put a "V" before all source-names.
The probe command is necessary since by default only voltages are saved.
Hit "h" to run HSPICE. At the end there will be an error "Aborting, can't find data output file circuit.tr0"
Switch to another terminal, change to the directory where your schematic is located
Start "awaves", which looks like the following:

In "awaves" there will be a results browser, where you simply double-click on "I(M_0)".

How does it work?

Its a very straight forward process: Sue produces a spice netlist with all transistors and sources on the schematic webpage. Then it loads the transistor models for the AMI 0.5um technology and adds them to the netlist. Finally it puts all text that starts with "^" into the netlist. Thats the way to specify what kind of simulation to run. Usually you want to run a transient simulation, so you use the ".tran stepsize stoptime" command. Stoptime is the total time you want to run the simulation and stepsize is the maximum time step HSpice will take.

Instead of putting symbols for the input signals, you can also put commands like ".dc" onto the schematic page. Anyting that follows the HSpice syntax is allowed.

If something fails, look in the Sue command window for a "*error*" message.

1/30/02 Johannes Grad