Virtuoso AMS Environment User Guide

3

Setting Up the AMS Environment

This chapter contains the following sections:

■Overview on page 58

■The hdl.var File on page 58

■The ams.env Files on page 59

■Specifying the Text Editor to Use on page 60

■Specifying Fonts for the Cadence Hierarchy Editor on page 60

■Preparing to Use AMS Designer from the Hierarchy Editor on page 62

Virtuoso AMS Environment User Guide

Setting Up the AMS Environment

Overview

Several configuration files help you manage your data and control the operation of the tools used in the AMS environment. Among them are

■cds.lib

Defines your design libraries and associates logical library names with physical library locations. For more information, see “The cds.lib File” in the “Setting Up Your

Environment” chapter of the Virtuoso AMS Simulator User Guide.

■hdl.var

Defines variables that affect the behavior of tools and utilities. For more information, see “The hdl.arv File” on page 58.

■setup.loc

Specifies the search order that tools and utilities use when searching for thecds.lib, hdl.var, and ams.env files. For more information, see“The setup.loc File” in the “Setting Up Your Environment” chapter of theVirtuoso AMS Simulator User Guide.

■ams.env

Specifies the basic behavior of AMS Design Prep and the AMS netlister. For more information, see “The ams.env Files” on page 59.

The AMS environment and the AMS simulator operate on and store data in libraries that are organized according to a Library.Cell:View (L.C:V) approach. For more information, see “The Library.Cell:View Approach” in the “Setting Up Your Environment” chapter of theVirtuoso AMS Simulator User Guide.

The hdl.var File

The hdl.var file is an ASCII text file that contains

■Configuration variables, which determine how your design environment is configured. These include

Variables that you can use to specify the work library where the compiler stores compiled objects and other derived data. For Verilog-AMS, you can use the

LIB_MAP or WORK variables.

For Verilog-AMS, variables (LIB_MAP, VIEW_MAP, WORK) that you can use to specify the libraries and views to search when the elaborator resolves instances.

Virtuoso AMS Environment User Guide

Setting Up the AMS Environment

■Variables that allow you to specify compiler, elaborator, and simulator command-line options and arguments.

■Variables that specify the locations of support files and invocation scripts.

For example, the hdl.var file for the included tutorial contains the following:

softinclude $AMSHOME/tools/inca/files/hdl.var define WORK amslib

define NCVLOGOPTS -linedebug

define VIEW_MAP ($VIEW_MAP, .vs => shell)

You can have more than one hdl.var file. For example, you can have a projecthdl.var

file that contains variable settings used to support all your projects and localhdl.var files, located in specific design directories, that contain variable settings specific to each project, such as the setting for the WORK variable.

For more information about the hdl.var file, see“The hdl.arv File” in the “Setting Up Your Environment” chapter of the Virtuoso AMS Simulator User Guide.

The ams.env Files

The ams.env files are ASCII files that specify the basic behavior of AMS Design Prep and the AMS netlister. Cadence supplies a default ams.env file, which you can change to meet your needs. Perhaps the most convenient way to change the settings is to use the graphical interfaces available by choosing either Tools – AMS – Options from the CIW menu or AMS – Options from the Cadence hierarchy editor menu. For information about using these graphical interfaces, see “Specifyingthe Behavior of the Netlister and Compilers” on page 74. For detailed descriptions of the variables used in the ams.env file, seeAppendix A, “Variables for ams.env Files.”

The Cadence default ams.env file isyour_install_directory/share/cdssetup/ amsDirect/ams.env. You can also have other ams.env files tailored to your needs. The

AMS tools search for such files using the search mechanism described in the“Cadence Setup Search File: setup.loc” chapter of the Cadence Application Infrastructure User Guide.

Day-to-day changes in the ams.env files result from changes you make in the graphical interfaces, but if you need to create or edit an ams.env file directly, be aware of the following:

■Lines beginning with a semi-colon are considered comments.

■AMS Designer never writes comments to the ams.env files that it generates or overwrites. That means that if you add a comment to an ams.env file that AMS Designer reads and then writes, the comment disappears. For example, any comments you add

Virtuoso AMS Environment User Guide

Setting Up the AMS Environment

to the ams.env file in the run directory disappear as soon as you apply any changes to the options.

AMS Designer Supports Design Management

Design management controls access to design files to ensure that information remains synchronized as the design changes. AMS Designer supports design management for all components of a design except for

■The cds_globals module

■The contents of temporary (TMP) libraries

As described in the Cadence Library Manager User Guide, design management reacts to the settings of certain environment variables, such as CDS_AUTO_CKIN. You might need to change the value of these variables to obtain the design management behavior you want.

Specifying the Text Editor to Use

You can specify the text editor for AMS Designer by defining the UNIX shellEDITOR or CDS_TEXT_EDITOR variables. The value of the CDS_TEXT_EDITOR variable takes precedence over the value of the EDITOR variable. For example, the command

setenv CDS_TEXT_EDITOR emacs

sets up the UNIX environment so that AMS Designer uses the emacs text editor.

Specifying Fonts for the Cadence Hierarchy Editor

By default, the Cadence hierarchy editor uses a variable-width font for messages. However, some messages, such as error messages that include pointers, are best viewed with fixedwidth fonts. The easiest way to view such messages in a fixed-width font is to use the

NCBrowse window. (For more information, see “Viewing Messages” on page 289.) If you prefer to see messages in a fixed-width font in the hierarchy editor, you can change the hierarchy editor font.

For example, you notice a case like the one illustrated below where the error pointer bar is misaligned. The pointer should point to the last character in the initial statement, but does not. The problem arises because the default font used in the hierarchy editor is a variable-

Virtuoso AMS Environment User Guide

Setting Up the AMS Environment

width font but the alignment of the pointer is calculated as though the font were a fixed-width font.

To align the pointer properly, you can change the variable-width font to a fixed-width font by substituting a statement like

CDS.textFont=courier plain 10

for the original statement in the cdsresource.properties file. (For the steps involved, see “Changing the Hierarchy Editor Fonts” in Chapter 1 of the Cadence Hierarchy Editor

User Guide.)