Product Documentation
Virtuoso Technology Data ASCII Files Reference
Product Version IC23.1, June 2023

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The ASCII Technology File

An ASCII technology file defines the contents of a technology database. This chapter contains high-level information about a technology file. It contains the following topics:

Introduction to the ASCII Technology File

An ASCII technology file defines the contents of a technology database. Specifying the data for incremental technology databases in multiple technology files and compiling the ASCII technology files in their reference order creates an incremental technology database graph. This guide details how to specify data in an ASCII technology file.

Each ASCII technology file is made up of sections and subsections that must be specified according to the structure and syntax. The various sections of the technology file allow you to specify and define technology file controls; design layers, layer attributes, sites, vias, and devices; design constraints; and the layer display in the Palette.

When you specify a constraint, you must use its proper name, as defined in the Virtuoso Technology Data Constraints Reference, and specify it according to the ASCII syntax defined in this manual. Conforming to these guidelines allows interoperability between tools, which means that the constraints can be interpreted by any applications that use them.

To provide the greatest flexibility and satisfy the needs of a wide range of applications, the technology file provides a place to define many different constraints and rules. Applications can require that you define specific technology data and constraints in your technology file. Refer to the documentation for any application you are using to determine the technology file requirements and to ensure that your technology data is complete and is used by the application. User-defined technology data can be included in the technology file, but is not recognized or used by Cadence applications.

The technology file also allows you to set up multiple constraint groups that define design constraints, which can then be applied during design sessions based on the applications in use. Constraint groups allow a flexibility of application that is not characteristic of design rules specified in other parts of the technology file. Refer to the application documentation to determine the constraint groups it recognizes and the order of precedence it applies to them.

A technology file must be compiled with the Technology Tool Box New or Load command before it can be used. ASCII technology file functions cannot be typed directly into a shell window or the Command Interpreter Window (CIW); they can be specified only in an ASCII technology file. The Virtuoso Technology Data User Guide contains detailed information about setting up and creating incremental technology databases, including information important for specifying ASCII technology files, such as information about planning technology database contents and about the technology data you can and cannot duplicate in multiple technology databases in a graph.

Another important file in this context is a display resource file. It defines the packets that the design software uses to display the layers in your design. It also defines the different display devices, such as monitors and plotters, that you use. For display resource file syntax, see Display Resource File.

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Technology File Structure

The technology file contains the following statements and sections:

Technology file section Establishes Technology file subsection

Statement: include

A file to be included in the technology file

N/A

Statement: comment

A comment to be preserved during technology file loading and dumping

N/A

controls

A process node setting for the technology database

processNode

Technology file version

techVersion

Technology parameters for use throughout the technology file

techParams

Distance measure type: Euclidian or Manhattan

distanceMeasure

Units for view types

viewTypeUnits

Overall design manufacturing grid resolution

mfgGridResolution

An ordered list of reference technology databases

refTechLibs

A process family name for the technology database

processFamily

The fabric type of the technology database

fabricType

layerDefinitions

Layers

techLayers

Layer purposes

techPurposes

Priorities for layer-purpose pairs

techLayerPurposePriorities

Displays

techDisplays

Properties on layers

techLayerProperties

Derived layers

techDerivedLayers

layerRules

Equivalent layers

incompatibleLayers

Layer functions

functions

Layer attributes

analysisAttributes

Layer manufacturing resolutions

mfgResolutions

Layer routing directions

routingDirections

Electrical characterization rules

Specified as currentDensity or currentDensityTables rules:

constraintGroups

Constraint groups

N/A

siteDefs

Scalar site definitions

scalarSiteDefs

Array site definitions

arraySiteDefs

viaDefs

Standard via definitions

standardViaDefs

Custom via definitions

customViaDefs

viaSpecs

Via specifications

N/A

devices

(Activates) predefined Cadence device classes, declares devices, establishes multipart path templates, and defined templates for waveguide objects

tcCreateCDSDeviceClass

ruleContactDevice

multipartPathTemplates

waveguideTemplates

leRules

Layers displayed initially in Palette

leLswLayers

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Syntactical Guidelines for an ASCII Technology File

See Virtuoso Technology Data User Guide for information about properly planning and defining data to fit into an incremental technology database graph. This manual focuses on the data you can specify in an individual ASCII technology file, without consideration for setting one up for an incremental technology database.

Consider the following guidelines for specifying technology file data in an ASCII technology file:

Do not apply properties or attributes to system-reserved layers or purposes. The software discards any user customization applied to reserved layers or purposes.

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