Virtuoso AMS Environment User Guide

Using External Text Designs

Using Modules Located in a Cadence Library

Once your modules are located in Cadence libraries, there are many tools that you can use to analyze and manipulate the modules. Perhaps the most important tool for the AMS environment is the Cadence hierarchy editor. With the hierarchy editor, you can create a configuration for your design and then run through the simulation process.

Creating a Configuration

The Cadence hierarchy editor greatly facilitates the process of building components into your design by allowing you to create configurations that specify the view to be used for each cell.

If you need more information about creating a configuration, see“Creating Config Cellview” on page 200.

If you use the AMS template to create a configuration, the resulting configuration selects the views verilogams, veriloga, behavioral, functional, schematic, and symbol. However, if your design was created outside of the AMS environment, the AMS_Compatibility template might do a better job of selecting appropriate views. Note that any selected symbol views must be associated with a model that the AMS simulator can use to describe the device.

If a newly created configuration does not automatically select the views that you need for each of the cells, you can select views manually. For guidance, see the “Defining Cell-Based

Bindings and View Lists” section, in the “Overview” chapter of theHierarchy Editor Help. The goal is to be sure that the views you want to simulate are actually specified in the configuration.

Preparing for Simulation

The AMS entry, in the Cadence hierarchy editor menu, provides several tools that can help you prepare for and run a simulation that uses text modules.

■AMS Design Prep, which you run by choosing AMS – Design Prep, generates a cds_globals module. This module contains information about global signals and design variables contained in any translated schematics but not about those within text modules. If your text modules contain global signals or design variables, you can edit the cds_globals module to add them.

■Choosing AMS – Options opens a form that allows you to set options for the elaborator and the simulator.

■Choosing AMS – Run Simulation opens a form that allows you to run the simulator.

Virtuoso AMS Environment User Guide

7

Using Existing Designs in the AMS

Environment

This chapter explains how to use analog primitives and SPICE and Spectre® netlists and subcircuits.

This chapter contains the following sections:

■Using Analog Primitives on page 188

■Using SPICE and Spectre Netlists and Subcircuits on page 188