About Netlist Exporter

Front End Flow (FEF) is a design flow tool in which the Advanced Design System (ADS) schematic editor is used as a single point of entry to drive an entire design flow. ADS supports three other design flow tools: Netlist Translator, Intermediate File Format (IFF), and RFIC Dynamic Link.

Design Flow Tool Overview

Netlist Translator	Third party schematic entry tools are used to create SPICE or Spectre netlists. The netlists are translated into ADS netlists or schematics. This requires that schematic data be duplicated and synchronized in multiple environments.
IFF	ADS is used as a schematic entry tool. The schematic is transferred from ADS to other tools using IFF to complete the design. This requires that schematic data be duplicated and synchronized in multiple environments.
RFIC Dynamic Link	A single schematic entry tool, Cadence Virtuoso Composer, is used as the point of entry for schematic designs. ADS is used to add test bench data around the top level IC schematic symbol. All of the schematic data is represented in a single environment (Cadence); and there is a limited link to the ADS simulation tools and Instrument Server.
Front End Flow	Front End Flow allows all schematic design entry to be done in ADS. There is a single data representation for the schematic data with a direct link to the ADS simulation tools and Instrument Server. In addition, there are new customizable netlisters and tool interfaces available to allow the ADS schematic tool to interface with third party layout and Layout Verses Schematic (LVS) tools.

Front End Flow

The Front End Flow tool enables you to perform the following:

• Create schematic and layout designs from a single design entry point (ADS).
• Use the powerful ADS simulation and Instrument Server tools.
• Use third-party layout and LVS tools while maintaining a single schematic data source (no redundant data to maintain).
• Use third-party simulation tools.
  Front End Flow can be used to generate netlists on one platform that are transferred to other systems. This is necessary in cases where the third party tool does not run on the same system as ADS. For example, you may be running ADS on a PC and an LVS tool from Cadence that will only run on UNIX.

Design Flow Using Front End Flow

The key feature of the ADS Front End Flow tool is a configurable netlister that is able to target the netlist format required for any CAD tool. The most common target format is HSpice, which is supported by many CAD tools. ADS includes configurations for several HSpice derived formats including those for Cadence Assura, Cadence Dracula, and Mentor Graphics* Calibre. In addition, the netlister can be configured by modifying certain functions to support any other target format. The Netlist Exporter Installation and Configuration Guide covers the steps required to custom configure the Front End Flow netlister.
Front End Flow Flowchart depicts the design flow using the Front End Flow tool. Note that the Front End Flow netlister can generate netlists for several different tools.

Front End Flow Flowchart

General Process

The following describes the typical task flow using Front End Flow. Refer to Simplified Task Flow.

1. A schematic design is created within ADS.
2. This design is simulated using ADS.
3. When the simulation results match the circuit specification, a layout for the schematic is generated.
4. The Front End Flow netlister can create netlists that can be utilized to generate layouts, such as VirtuosoXL.
5. Once the layout has been generated, an LVS tool is used to verify that the layout representation is the same as the schematic representation.
6. To do this, a netlist is generated in an appropriate format for an LVS tool. Additionally, a layout extraction utility generates a netlist that the LVS tool will compare to the Front End Flow netlist.
7. When the layout and schematic match, the layout extractor can be used to generate netlists with parasitics.
8. If ADS is not the simulator used for the parasitic resimulation, the Front End Flow netlister can generate a netlist for a third party simulator.
9. Resimulate the netlist.

Simplified Task Flow is a simplified task flow for using Front End Flow.

Simplified Task Flow

Intended Audience

The audience intended for this manual consists of CAD System Administrators and RFIC Designers who are using Advanced Design System 2001 or newer to create RFIC designs. It is assumed that the designer using Front End Flow has some working knowledge of Advanced Design System. This manual does not cover how to use third party tools that can be accessed from ADS. For information on other vendor's tools, consult that vendor's manuals.

Main

Main Requirements

To use Advanced Design System Front End Flow, you must have Advanced Design System 2001 or newer installed. Front End Flow can be used on all platforms that are supported by Advanced Design System.

What's in this Manual

The goal of this manual is to help you get started, provide relevant examples that teach you how to set up and use the software and show you where you can get more information as you need it.
Creating Netlists provides step by step instructions for generating netlists using Front End Flow. This chapter covers procedures to use the pre-configured Front End Flow tools. Refer to the Netlist Exporter Setup documentation for instructions on generating custom netlists.