This article describes how to use SmartSpice to run simulations from within the Cadence design framework. The process described below requires the Cadence HSPICE Socket feature to be installed.

What Makes It Work

When the user requests a simulation from a Cadence schematic, the Cadence software will use a script called hspice, (in the case of Meta-Software's HSPICE). The scripts supplied by Silvaco will override Meta-Software's script. The override enables SmartSpice to run.

Initial Setup

Before starting the Cadence Design Framework, ensure $SILVACO/bin is in your path, then enter:

ssi -Cadence <framework> [-e] [-i]

where <framework> is one of

-artist

-composer

depending on which environment you will be running simulations from.

The -e option allows you to edit the input deck before starting SmartSpice. This can be used to add extra control statements, e.g. .MODIF, to the input deck, or edit the netlist without modifying the schematic. (See the "Running a Simulation with -e option " section).

The -i option allows SmartSpice to run interactively, i.e. displays SmartSpice windows rather than run in batch mode (default).

This procedure will create a hspice script file in ~/bin.

You should also ensure that ~/bin precedes the path that points out to Meta Software HSpice script. Type 'which hspice' to verify this. The ~/bin prefix will ensure that the ~/bin/hspice script is used to run SmartSpice rather than Meta-Software's hspice.

You may then start the Cadence framework.

Figure 1 shows how a simulation is run from the Composer environment and Figure 2 is for Analog Artist.

Running a simulation with -e option

Figure 1. How to run a simulation from the Composer environment

Run the simulation -

COMPOSER: DesignEntryWindow ->Simulation

->Netlist/Simulate

ARTIST: AnalogArtist->Simulation->Run

To edit/view the input deck before SmartSpice simulations are run, wait for the simulation log to display the following message:

COMPOSER: Begin simulation

(Displayed in Run Log window)

ARTIST: HSPICE Execution

(Displayed in Analog Artist

window)

then in a cmdtool/xterm connected to the machine where SmartSpice will be executed, enter:

% ssi connect

this will produce output similar to:

****** Connection to SmartSpice established ******

Spice input deck can now be edited

Full path: {path}/{design}.run1/si.in

After editing reply 'ssi continue' - to continue,

'ssi quit' - to quit

The input deck can then be edited, for example

% vi {path}/{design}.run1/si.in

when modifications to the input deck are completed enter:

% ssi continue

to continue with the simulation, or

% ssi quit

to abort the simulation.

One of the following messages will be displayed:

SmartSpice started at Wed Mar 27 11:39:25 PST 1996

****** Simulation completed Wed Mar 27 11:40:55 PST 1996 ******

Figure 2. How to run a simulation from the Analog Artist environment.

this message indicates that the simulation completed successfully, or

****** SmartSpice bypassed ******

this message indicates that SmartSpice was not run, ie the user aborted the simulation

Output can then be viewed using the Waveform viewer.

Examples:

Run SmartSpice under the Artist simulation environment

% ssi -Cadence -artist

Run SmartSpice under the Composer simulation environment

% ssi -Cadence -composer

As above but allows the user to intercept the simulation job allowing the input deck to be edited

% ssi -Cadence -composer -e

The above commands may be entered at any time while the Cadence Framework is running allowing you to change the environment under which SmartSpice will be run. For example, you do not have to restart the Framework if you want to change the framework you will be using or if you want to run interactive SmartSpice.