Altium Designer Documentation

Project Options - Class Generation

Modified by Susan Riege on Oct 25, 2018
All Contents

The Class Generation tab of the Project Options dialog

Summary

This tab of the Project Options dialog enables you to configure and control class generation. Classes are a logical collection of a particular type of design object. For example, a group of related components could be grouped into their own Component Class, which could then be used as the basis for creating a targeted rule. This tab provides controls to determine which classes are automatically generated and which user-defined classes are generated when the source schematic documents are synchronized with the PCB design document.

Access

This dialog is one of multiple tabs available when configuring the options for a project and is accessed from within the Project Options dialog. To access the Project Options dialog:

  • From the PCB or schematic editor, click Project » Project Options.
  • Right-click on the project name on the Projects panel then click Project Options from the context menu.

Options/Controls

Automatically Generated Classes

  • Generate Net Classes for Buses - check this option to automatically generate a net class for each bus in the design. The members of a class will be the individual constituent nets of the bus (from which that class was generated).
A generated net class will be named using the name of the bus.
  • Generate Net Classes for Components - check this option to automatically generate a net class for each component in the design. The members of a class will be the associated nets to which the pins of the component (from which that class was generated) are connected.
A generated net class will be named using the designator of the component in the format <ComponentDesignator>_Nets.
  • Generate Separate Net Classes for Bus Sections - check this option to automatically generate a separate net class for each bus section. A bus section is created by specifying a bus which is actually a section of a larger bus, for example D[15..8], from the bus D[15..0].
  • Generate Net Classes for Named Signal Harnesses - enable this option to automatically generate a net class for each named signal harness in the design. The members of a class will be the nets associated to the signals gathered by the named signal harness (from which the class was generated).
A named signal harness is one that has a net label attached to it. A generated net class will be named using the name of the net label attached to the signal harness.
  • Sheet-Level Class Generation Grid - this region allows you to control the automatic generation of component and/or net classes at the individual schematic sheet level. All source schematic sheets for the project are listed with the following information presented for each:
    • Sheet Name - the name of the schematic document.
    • Full Path - the absolute path to the folder in which the document resides.
    • Component Classes - check this option to have a component class generated for the sheet.
    • Net Classes Scope - use this field to determine whether to have a net class generated for the sheet and, if so, the scope of generation. The field's drop-down provides the following choices:
      • None - do not generate a net class for this sheet.
      • Local Nets Only - generate a net class for this sheet but only containing member nets that are local to the sheet.
      • All Nets - generate a net class for this sheet that contains all member nets associated with the sheet (local and those that go elsewhere).
    • Structure Classes Generate Structure - check this option to have a structure class generated for the sheet.
Enable/disable component class generation or set the scope for net class generation as a whole using commands available from the right-click context menu for a column. Multiple sheet entries can be selected using standard multi-select techniques (Ctrl+click, Shift+click, click&drag).
For components and/or nets on the top sheet, the respective component and/or net class will be named using the schematic document name. For components and/or nets on child sheets, the respective component and/or net classes will be named using the sheet symbol designators.
The text at the bottom of this region dynamically changes based on the choices made and provides a summary of which classes will be automatically generated.

User-Defined Classes

  • Generate Component Classes - check this option to generate user-defined component classes when the design is transferred to the PCB. Component classes are manually defined on the schematic by adding a ClassName parameter to targeted components and setting its value to the desired class name.
  • Generate Rooms for Component Class - check this option to generate rooms based on the user-defined component classes. These components need to have the component parameter with 'ClassName' as its parameter name.
  • Generate Net Classes - check this option to generate user-defined net classes when the design is transferred to the PCB. Net classes are manually defined on the schematic through use of the Net Class directive. To make a net a member of a Net Class, attach a Net Class directive to the relevant wire or bus (or a blanket) and set the value of the its ClassName parameter to the desired class name.
Note: To generate classes (automatic and/or user-defined) when transferring the design to the PCB, you must ensure that the respective Comparator settings have been set to Find Differences on the Comparator tab of the Project Options dialog. For net classes, this is the Extra Net Classes comparison type found in the Differences Associated with Nets category. For component classes, this is the Extra Component Classes comparison type found in the Differences Associated with Components category.

 

In addition, you must ensure that the respective ECO settings have been set to Generate Change Orders on the ECO Generation tab of the Project Optionsdialog. For net classes, this is the Add Net Classes modification type found in the Modifications Associated with Nets category. For component classes, this is the Add Component Classes modification type found in the Modifications Associated with Components category.
Found an issue with this document? Highlight the area, then use Ctrl+Enter to report it.

Contact Us

Contact our corporate or local offices directly.

You are reporting an issue with the following selected text
and/or image within the active document:
ALTIUM DESIGNER FREE TRIAL
Altium Designer Free Trial
Let’s get started. First off, are you or your organization already using Altium Designer?

If would like to speak with a representative, please contact your local Altium office.
Copyright © 2019 Altium Limited

In that case, why do you need an evaluation license?

If would like to speak with a representative, please contact your local Altium office.
Copyright © 2019 Altium Limited

Got it. You actually don’t need an evaluation license for that.

Click the button below to download the latest Altium Designer installer.

Download Altium Designer Installer

If would like to speak with a representative, please contact your local Altium office.
Copyright © 2019 Altium Limited

Please fill out the form below to get a quote for a new seat of Altium Designer.

By clicking “Get Your Free Trial”, you are agreeing to our Privacy Policy.
You may receive communications from Altium and can change your notification preferences at any time.

If you are on Altium Subscription, you don’t need an evaluation license.

If you are not an active Altium Subscription member, please fill out the form below to get your free trial.

By clicking “Get Your Free Trial”, you are agreeing to our Privacy Policy.
You may receive communications from Altium and can change your notification preferences at any time.

Why are you looking to evaluate Altium Designer?

If would like to speak with a representative, please contact your local Altium office.
Copyright © 2019 Altium Limited

You came to the right place! Please fill out the form below to get your free trial started.

By clicking “Get Your Free Trial”, you are agreeing to our Privacy Policy.
You may receive communications from Altium and can change your notification preferences at any time.

Sounds exciting! Did you know we offer special discounted student licenses? For more information, click here.

In the meantime, feel free to request a free trial by filling out the form below.

By clicking “Get Your Free Trial”, you are agreeing to our Privacy Policy.
You may receive communications from Altium and can change your notification preferences at any time.

Got it. You can download a free Altium Designer Viewer license which is valid for a 6 months.

Please fill out the form below to request one.

By clicking “Get Your Free Trial”, you are agreeing to our Privacy Policy.
You may receive communications from Altium and can change your notification preferences at any time.

That’s great! Making things is awesome. We have the perfect program for you.

Upverter is a free community-driven platform designed specifically to meet the needs of makers like you.

Click here to give it a try!

If would like to speak with a representative, please contact your local Altium office.
Copyright © 2019 Altium Limited

Got it. You can download a free Altium Designer Viewer license which is valid for a 6 months.

Please fill out the form below to request one.

By clicking “Get Your Free Trial”, you are agreeing to our Privacy Policy.
You may receive communications from Altium and can change your notification preferences at any time.