Sigasi Studio Manual

Setting Up Sigasi Studio

Distribution and flavours

Sigasi Studio is distributed online. It is available in two versions: as a stand-alone application or as a plugin inside a standard Eclipse installation. Your license gives you the right to use either version, at any time, at your discretion. Therefore, your first task is to decide which version suits your requirements, based on the description below. Depending on the chosen version, you should then follow the corresponding installation instructions.

Sigasi Studio App

The stand-alone application has the following characteristics:

Sigasi Studio Eclipse plugin

The Eclipse plugin has the following characteristics:

Installation of Sigasi Studio App

To download and install Sigasi Studio as a stand-alone application, follow the online Installation Instructions.

After downloading, choose or create a folder where you want to install the software and unpack the archive there. The archive contains a single top-level folder called sigasi. Inside the folder there is an application startup file, also called sigasi. Start the application by executing this startup file.

If you are using RedHat Linux 6 or CentOS 6, you need to follow the Plugin installation instructions as explained here.

Running Sigasi Studio with multiple users on the same server

Starting with Sigasi Studio 3.8, the Sigasi launcher listens on port 4444. To avoid conflicts on this port when Sigasi Studio is used on a server with multiple users concurrently, the following changes need to be made:

This way Sigasi Studio uses the default Eclipse behaviour (instead of the custom sigasi runner): more info

Installation of Sigasi Studio Eclipse Plugin

There are two ways to install the Sigasi Studio Eclipse Plugin:

  1. On-line installation of the Eclipse Plugin
  2. Off-line update site to install the Eclipse Plugin (only for customers with XL or XPRT licenses)

Prerequisites: Eclipse

Eclipse Foundation member

For more information on system requirements: System Requirements

Install the Eclipse Plugin

This requires the host where you install the Sigasi Studio Plugin to have access to our download server. After starting Eclipse:

  1. Click Help > Install New Software…
  2. In the Work with: field enter and press enter.
  3. Check the checkbox next to Sigasi Studio
  4. We recommend to install the optional features too.
    Install Sigasi Studio plugin
  5. Click the Next button.
  6. The following steps are pretty self-explaining.
  7. After the installation you will need to restart Eclipse. Once this is done, go to Window > Perspective > Open Perspective > Other… and select the Sigasi Perspective. You can then close the Welcome View to show the Sigasi Views.

Installing the offline update site

This feature is supported for customers with Sigasi Studio XL or Sigasi Studio XPRT licenses.

Installing the offline update site is very similar to installing from the main update site, where step 2 is replaced with these steps:

  1. Download the offline update site from the link you received from your sales representative.
  2. In the Install Wizard, click Add…
  3. Click Archive…, browse to the zip file you downloaded, and confirm with OK.
    Add offline update site archive

Next, continue with step 3. in the general eclipse installation instructions. It is recommended to disable the option Contact all update sites during install to find required software when installing the offline update site.


The license key can be filled in under Window > Preferences > Sigasi > License Key.

More details can be found here. The license unlocks the features for your edition.


Sigasi Studio stores its projects on the file system in one or more workspaces.

When you start the tool for the first time, it will propose to create a workspace for you:

Choose workspace

Although you can work with multiple workspaces, we recommend to use a single workspace for all your projects.

Software updates

Sigasi Studio has an automated update system. When updates are available, you are notified by a pop-up window called Updates Available in the bottom right corner:


If you want to install the updates, click anywhere in the pop-up window. After a few seconds, a new window will appear with further instructions.

The updates can be postponed by closing the pop-up. You can perform the updates at any time by clicking the Update icon-icon in the status bar at the bottom of the screen.

It is good practice to first create a backup of your installation folder before running an update. This can be done by simply compressing the eclipse or the sigasi folder in an archive (zip file)

Sigasi Studio App

If you run Sigasi Studio as a standalone application, the automated update system will periodically check for software updates.

Sigasi Studio Eclipse plugin

If you run Sigasi Studio as an Eclipse plugin, you may need to check for updates manually, by clicking Help > Check for Updates.

You can enable automatic updates by opening this preference page : Install/Update > Automatic Updates. Next enable Automatically find new updates and notify me. Feel free to modify any of the available options.

Firewalls and Proxies

If the updates are not automatically fetched from the Sigasi Studio update server you are probably behind a firewall or proxy server. You can configure Sigasi Studio’s proxy settings in Window > Preferences > General > Network connections. If you can not add a firewall exception for our update site, the fall back solution is to download the complete application from our website. You can completely replace your old installation; all settings are stored in your workspace (the default is workspaceSigasi in your home directory).

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Setting Up a Project


Your work with Sigasi Studio typically is organized as a project. A project is a collection of VHDL and/or (System)Verilog files that belong together. Sigasi Studio understands the HDL units defined in the files, and the relationships between them.

Your first step is to set up a project. There are a number of ways to do this. The most common ways are:

These two methods and other methods are discussed in detail in the following sections.

Importing a project from the file system

1: Import the project

You can import an existing VHDL or (System)Verilog project from the file system by clicking File > Import… > Sigasi > Import a VHDL project (or Import a (System)Verilog project). Browse to the root directory of the project, and press Finish.

2: Set Libraries (VHDL or Mixed)

Since Sigasi Studio 4.4, Sigasi Studio automatically configures libraries of imported projects, based on project information such as library and use clauses. If you need to customize the library configuration, you can assign different libraries to your files and folders. Right-click on a file or folder and select Library Mapping > New Library…. Then fill out the correct library name.

3: Add any files that are in other directories

If you need additional files that are not in the project root directory, just drag them from your Windows Explorer (or other file browser) into the project. You will have the option to create a link rather than copying the files.

Note 1: dragging files works on Windows (using Windows Explorer), on Mac OS X (using Finder) and on Linux (using Gnome Nautilus). If you use KDE, you should install Nautilus.

Note 2: to avoid absolute paths in the .project file, environment variables can be used. Right-click the file or directory in the project explorer and select Properties > Resource > Location > Edit… to configure the path of the resource. To access environment variables, you have to prefix the environment variable with ENV-. For example: to refer to the home directory you can use ENV-HOME.

Creating a new, empty project

To create a new project, select File > New > VHDL Project or File > New > (System)Verilog Project. Then give your project a name.

By default, the Use default location checkbox is checked, which means that new projects will be located in the workspace folder. Alternatively, you can uncheck the checkbox and choose an arbitrary location for your project. This is especially useful if you want to use Sigasi Studio with an existing design.

You can also select the VHDL version or the version of .v files.

After creating a new project, you can add existing files by dragging them from your filesystem into the project explorer. New files can be added by clicking File > New > VHDL file or File > New > (System)Verilog file.

Other ways to set up a project

Adding VHDL or Verilog support to an existing Eclipse project

You can also add VHDL or Verilog support to any project in your workspace by right-clicking the project in the project explorer and selecting Configure > Add VHDL support or Configure > Add (System)Verilog support. You can also remove VHDL or Verilog support from Sigasi Studio projects by selecting Configure > Remove VHDL support or Configure > Remove (System)Verilog support.

Note that only with a Sigasi Studio XL license, you can have mixed VHDL and Verilog support at the same time.

With a Sigasi Studio Creator license, a project can contain both VHDL and Verilog files, but only one of the languages will have full support. Files in the other language will be treated as External Files.

Importing a project from an archive

Sigasi Studio projects can be shared using file archives. All project-related settings are stored in two hidden files in the project folder. Therefore, you can create an archive of the entire top level folder (File > Export > General > Archive file) and send it to someone else.

You can import a project from an archive by clicking File > Import… > General > Existing projects into Workspace and selecting Select archive file. Browse to your project archive and press Finish.

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HDL libraries are a very powerful feature of the HDL languages. Sigasi Studio makes it easy to configure and use them. In this chapter, we assume that the basic concepts of HDL libraries are understood. We will explain how they are implemented in Sigasi Studio.

Like with any HDL tool, Sigasi Studio needs to know where the libraries are located on the file system. We will describe how the library configuration can be examined and modified using the GUI.

We will also present some use case about how to set up libraries with Sigasi Studio to organize your projects.

Examining the library configuration

You can examine the library configuration in the Libraries View and in the Project Explorer view. The Libraries view shows how design units are mapped. The Project Explorer view show how VHDL or SystemVerilog files are mapped.

In the Libraries view you can see a tree of all libraries in your projects. You can open each library to see all contained design units.

In the Project Explorer view each physical file or folder is annotated with the library it belongs to, between square brackets:

What you see here is the initial library mapping of a demo project (you can create such a project by selecting File > New > Other > Tutorial VHDL Project or Tutorial SystemVerilog Project).
In the screenshot we see a project called Demo, with a folder named Common Libraries. In that folder, you see the typical standard libraries (std and ieee) upon which all VHDL projects depend. The demo project itself consists of a few VHDL files.

Next to the project’s name Demo, is the annotation work. This means that, barring any overrides, everything in the project will be stored inside the work library.

Lower down, we see overrides. For example, the STD folder has an annotation std. This means that, again barring any further overrides, the entire contents of the STD folder will be mapped into the library std. There are no limits to the number of overrides that can be performed. If this needed, any individual file can be mapped to a separate library.

Modifying the library configuration

The library mapping for project files can be modified in the Libraries and Project Explorer view.

Select a file or a folder in the Project Explorer and right-click.

You get a Set Library context menu, with a number of options:

When you map a file into a library, only that file is affected. However, when you map a folder into a library, then everything in that folder will be mapped into that library. Any overrides in the folder and its sub-folders will be removed. When you are defining the library mapping for a new project you should map from top to bottom.

So in the case of our Demo project, you would change (if work is not a good default) the top folder’s mapping first and then override the mapping in the sub-folders.

When you are changing the library mapping of a project, the project will be rebuilt completely. In order to avoid several consecutive rebuilds while you are setting up your libraries, you can temporarily disable the automatic rebuilds, until you are finished setting up your library mappings. You can do this by disabling the Project > Build Automatically option.

To exclude a file from all libraries, the library mapping context menu provides an Exclude from build option. You can apply that to any file or folder in the project. Sigasi Studio will then assume that the corresponding resource is not a part of the project and will not include that resource in a project build. This is typically useful when you have stale copies of HDL files or folders lying around that you want simply to be ignored.

Configuration file

All library configuration information is stored in the .library_mapping.xml file in the root of your project. If you edit this file, your project will be cleared and rebuilt automatically (a so-called Clean Build).

Sigasi Studio only writes changes to this configuration file when you make changes to the library configuration with the context menu in the Project Explorer. When you do make changes, Sigasi Studio first checks that all paths in the library configuration still exist. If a path no longer exists, is will be removed from the configuration file. Note that the library configuration file is case-sensitive, even on Windows.

Common Libraries

Each VHDL project has a folder called Common Libraries. This is where reusable libraries go: either vendor libraries, third party IP libraries or your own reusable libraries. By default, the STD and IEEE libraries are added to this folder. The Common Libraries folder behaves like any other folder. You can delete it, rename it and apply a different library mapping. In most cases, however, the default configuration is just what you need.

How to add files to Common Libraries ?

In any newly created VHDL project, the Common Libraries folder contains the VHDL files of the IEEE and STD libraries. To add files to the Common Libraries folder, locate a folder with VHDL files on your file system using the Project Explorer or the file explorer of your OS and drag the folder with VHDL files to the Common Libraries folder.

How is Common Libraries different from another folder ?

Pre-compile Common Libraries

Xilinx and Intel (Altera) have recommendations on how to pre-compile their simulation libraries for use with with third party simulators.

What if I broke my Common Libraries folder?

If you have modified the Common Libraries folder, you can always revert it back to the original state. Right-click on the Common Libraries folder of your project in the explorer view and apply menu-entry Set Library > Reset Common Libraries.

IEEE Vital

See How can I use the IEEE Vital libraries with Sigasi Pro?

Shared libraries

Sigasi Studio allows you to share libraries between multiple projects. The easiest way to do this, is to develop each library in a separate project and configure the Project Dependencies accordingly. To configure the project dependencies, right click the project (the one that uses the shared library) and select Properties. Next click Project References and mark the library project as referenced project.

Using third party libraries

Many projects use third party libraries. These can be added to the project as any other set of VHDL files.

A number of popular third party libraries are the following:

VendorLibraryInstall dir example

On Linux the default installation location for Xilinx is /opt/Xilinx and /opt/altera for Altera.

For many common third party libraries, you can set up the library using a Quick Fix for third party libraries.


XilinxCoreLib is a very big library with more than a thousand entities and architectures. If you include all of these design units, it slows down the compilation phase of Sigasi Studio. In order to avoid that, Sigasi Studio only adds the packages with the component declarations to your project by default. It excludes the entities and architectures from compilation.

You can easily add selected entities (and architectures) to your project by right clicking the corresponding file (filename = entity name.vhd) in the Project Explorer, and selecting Set Library > xilinxcorelib.

Library errors from external compilers

If you are using the External Compilers, the external compiler can also put error markers on library clauses. You can easily verify this by checking the prefix of the error message (e.g. vcom: for vcom errors). Consult the Libraries section of the external compiler integration for more information on configuring libraries for your external compiler.

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User Interface

The Sigasi Studio perspective

Sigasi Studio is built upon the Eclipse platform, which permits to use multiple languages within a single environment. The user interface can be customized for a particular language. In Eclipse terminology, this customized user interface is called a perspective. The icon and name of the current perspective is highlighted in the upper right corner.

Sigasi Studio provides a Sigasi perspective to work with both VHDL and Verilog files.

If you use the standalone version of Sigasi Studio, this perspective is the default. If you use the Eclipse plugin, another perspective may be open instead. You can select the Sigasi perspective by clicking the button next the perspective icon. A window pops up in which you can select the perspective.

Quick Access

The Sigasi Studio toolbar contains a widget called Quick Access. This widget allows you to quickly find open editors, available perspectives, views, preferences, wizards, commands, etc. Simply start typing the name of the item you wish to invoke.

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When you open a project in Sigasi Studio, a number of views are presented in the user interface. Here is a typical screenshot, with the views highlighted.

The views provide alternative ways to access the information in a project. They permit efficient navigation, inspection and editing.

This chapter lists and explains the most important views in Sigasi Studio. Some views are not covered here, more specifically some views that are either inherited from Eclipse, or views that are provided by third-party plugins. Please refer to the Eclipse documentation or to the specific plugin documentation for further information on those views.

You can open a View in several different ways:

Project Explorer View

This view shows the directory structure of all files in all projects. You can use it to navigate to a particular file in your project and select it. When you double click on a file, the file opens in the Editor view. If you right-click a file, you see the context menu which offers extra commands.

You can customize the behavior of the Project Explorer view in ways that can be particularly handy for large projects. For example, if you click the Link with Editor icon , the Project Explorer will be linked to the Editor view. Now, the active file in the editor view will always be selected in the Project Explorer.

You can apply filters to choose which files are shown. Select the icon View Menu and then Customize view. You can then select a filter whose matching files will be hidden in the view. For example, you can filter out all non-VHDL or non-Verilog files.

Editor View

The Editor view shows the content of files, and allows you to edit files. It is a tabbed view so that multiple files can be open for editing simultaneously. The currently selected file is the active file.

Outline view

The Outline view displays the contents of the active file, in terms of the HDL objects that it contains.

You can sort the elements in the outline alphabetically, by enabling the sort button .

You can also filter all concurrent signal assignments from the outline by enabling the Hide Signal Assignments button . Double-click in the Outline view to navigate to the corresponding location in the editor.

If you enable the Link with Editor icon and you click an element in the outline view, the corresponding code will be selected in the editor.

Hierarchy view

The Hierarchy view shows the design hierarchy starting at a selected top level object. To choose a top level, open a file and right-click on an architecture (or entity or configuration or module). Then click Set as Top Level. Alternatively you can click the Set Top button in the hierarchy view to open a hierarchy top level selection dialog. You can use the filter field to quickly search for a certain top level.

The hierarchy view automatically refreshes itself when you save your design files. If you have a really large design this could slow you down. You can turn the automatic refresh on and off by toggling the refresh button .

To highlight the current selection of the HDL editor in the hierarchy view, enable the Link with Editor button . If the editor selection is part of the evaluated hierarchy tree, the corresponding hierarchy tree node will be selected.

The hierarchy view also shows the generic and constants values of VHDL components in the hierarchy. The internal compiler computes the generics and constants, even if they are passed down through the hierarchy, and even if arithmetic operations are used to define new values. If the value cannot be computed for some reason, the Hierarchy View will report the value to be unknown.

When you double-click an object in the hierarchy, the Editor view is updated accordingly, possibly by displaying the contents of a different file.

Use the instantiations filter , to hide everything except instantiations and structural statements are shown.

You can launch a simulation with the button, if you first set up an Launch simulator.

The Hierarchy View also offers an action Select required files, which selects all design files that are part of the current hierarchy, in the project explorer. This allows you to easily perform the same action on all files in the hierarchy. E.g. team commands, … [Only in Sigasi Studio XL]

You can also export a CSV-file with all dependencies of the selected element via the context menu: right click and select Export Dependencies to CSV file.

Problems view

The Problems view shows problems (errors and warnings) related to your code. These problems were reported either by the internal compiler or by an external compiler tool. You can navigate to the source of the problem by double clicking on a given problem. Problems can be sorted by clicking the column headers. The content of this view can be customized via the View Menu . Possible customizations are scope (workspace, project, selection), type, maximum number of problems, …

Libraries view

The libraries view shows the library mapping of the design units in all projects. You can use it to navigate to a particular design unit in your project. When you double click on a file, the file opens in the Editor view. If you right-click a file, you see the context menu which offers extra commands for setting libraries and for setting the top level.

If you enable the Link with Editor button , the Library view will be linked to the Editor view. Now, active file in the editor view will always be selected in the Library view.

Tasks View

It is common practice to add TODO and FIXME comments in your code. Sigasi Studio automatically scans your comments for TODO and FIXME tags and clearly highlights these comments with Task Tags. You can get a nice overview of all task markers in your workspace in the Task View (Windows > Show View > Tasks).

You can configure extra tags in the Task Tag preference page: Preferences > Sigasi > VHDL > Task Tags

Block Diagram View

[Only in Sigasi Studio XPRT]

The Block Diagram View displays a graphical (block diagram) view of all architectures, modules and their instantiations in your current VHDL or SystemVerilog editor. VHDL processes are also shown in the block diagram.

This viewer automatically updates when you save your code and gives a convenient way to visually inspect and navigate your code, even when your code is still unfinished or broken.

You can open the block diagram view by right clicking in the editor and selecting Show In > Block Diagram. Alternatively you can open the view via Window > Show View > Other… > Sigasi > Block Diagram.

You can also double click blocks, ports or wires to navigate to the corresponding HDL code. If you want to go into a block, you have to select it, right click and click Open Entity Declaration, Open Architecture or Open Module.

To find an object in the Block Diagram, you can navigate from your code to the Block Diagram. In your code, right-click a signal, port, process or instantiation and select Show In > Block Diagram - just like when opening the Block Diagram View the first time. If the Block Diagram already is open, the corresponding element is highlighted and the Block Diagram View is centered on it.

You can export the block diagram view to an image with the save button. Both SVG and PNG are supported. Choose a the *.svg filename for SVG export or a *.png filename for PNG export.

You can also export all block diagrams of an entire project at once: Click Project > Export… > Sigasi > Block Diagrams export and select your project. All SVGs will be created in diagrams/blockdiagrams/ in your project.

State Machine View

[Only in Sigasi Studio XPRT]

The State Machine View displays a graphical (bubble diagram) view of all state machines in your current VHDL or SystemVerilog editor. This viewer automatically updates while you are editing your code and gives a convenient way to visually inspect and navigate your code, even when your code is still unfinished or broken.

You can open the state machine view by right clicking in the editor and selecting Show In > State Machines. Alternatively you can open the view via Window > Show View > Other… > Sigasi > State Machines.

If you have documented your state transitions (i.e. the assignments), the comments will be added as text to the transitions in the view.

You can also double-click nodes or transitions to navigate to the corresponding HDL code.

With the button, you can toggle the display of edge labels. These labels show the code comments of the transition statements. You also have to option to Zoom In, Zoom Out or Zoom to Fit.

You can export the state machine view to an image with the save button. Both SVG and PNG are supported. Choose a the *.svg filename for SVG export or a *.png filename for PNG export.

You can also export all state machines of an entire project at once: Click Project > Export… > Sigasi > State Machine Diagrams export and select your project. All SVGs will be created in diagrams/statemachines/ in your project.

You can watch a screencast at State Machine Viewer.

Dependencies View

[Only in Sigasi Studio XL]

The Dependencies View visualizes the dependencies of your VHDL, SystemVerilog or mixed language projects. This view shows the relationships between your source files and makes it easy to see top levels and important packages. The Dependencies View also makes it easy to detect orphaned files.

The view is automatically updated each time you save your files.

Dependencies View for a complete project with libraries and design units

The dependencies view has following options:

The dependencies view can help you navigate too. Double click a file name in the diagram to open the corresponding editor.

The dependencies View can also be pinned. This prevents the diagram from changing when you switch editors.

You can export this diagram for documentation by clicking the save icon.

Documentation View

The Documentation view gives you a live preview of the automatic documentation Sigasi Studio can generate for your project.

Net Search View

[Only in Sigasi Studio XL] - [Only for VHDL]

With Net search, you can you to find loads and drivers of a net. A net is defined as a signal or port and all other signals and ports that are directly connected to it. The loads are where you read the value of the net and the drivers are where you write to this net.

To find the entire net of a signal or port, place your cursor on the identifier and right-click. Now select Find Net. Alternatively, you can press CTRL+SHIFT+H.

The Net Search view will appear. For big designs, it might take a while before the results appear.

From the Net Search view, you can navigate to the VHDL code by double-clicking the search results.

Preprocessor view

[Only for Verilog]

In the preprocessor view you can preview the expanded text of Verilog macros. This view automatically synchronizes with the active editor. When you select text in the (System)Verilog editor, the expanded text will be highlighted in the Preprocessor view. This also works the other way: when you select text in the Preprocessor view, the corresponding, original source will be selected in the editor.

Class Hierarchy View

[Only in Sigasi Studio XPRT] ,[Only for Verilog]

The Class Hierarchy view displays more information of the hierarchy of a class. It consists of a hierarchy tree and a list of the class members. To open the Class Hierarchy of a class, click the class name, right-click and select Open Class in Hierarchy (or press F4).

Class Hierarchy tree

The class hierarchy tree displays either the superclasses, subclasses or both.

Class HierarchyDisplays all superclasses and subclasses.
Superclass HierarchyDisplays all superclasses and implemented interface classes.
Subclass HierarchyDisplays all subclasses that extend or implement the selected (interface) class.
Show Qualified Class NamesShows the qualified name next to each class.

Member list

The member list shows all members of the class that is currently selected in the class hierarchy tree.

Show Inherited MembersShows or hides all members inherited from superclasses.
Sort By Defining ClassSorts members by the class in which they are defined.
Hide FieldsHides all fields in the members list.

Console view

When Sigasi Studio launches external tools (e.g. external compiler, documentation generation,…) the output is logged to the console view. This is a generic Eclipse view [Documentation].

Different tools can open different consoles. You can switch between different consoles by clicking the icon console display-icon.

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Sigasi Studio Editor

The Editor shows the content of files, and allows you to edit files. It is a tabbed view so that multiple files can be open for editing simultaneously. The currently selected file is the active file.

VHDL and SystemVerilog Editor

The VHDL and SystemVerilog (or Verilog) editors are optimized to help you browse and edit VHDL and SystemVerilog code. Most browsing and editing features are similar for both languages.

Language specific features are explained in “VHDL Specific” and “SystemVerilog Specific”.

Code highlighting (syntax coloring)

As all editors, Sigasi Studio colors your code to make the structure more clear. Unlike other tools, Sigasi Studio offers coloring based on the meaning of a word, rather than just the syntax.

Sigasi Studio supports both syntax highlighting and semantic highlighting. Syntax highlighting colors pieces of code according to the lexical class the code belongs to, such as a keyword or string. Semantic highlighting means that code gets colored according to their meaning. For example a constant is shown in another color than a signal.

Code highlighting is fully configurable. Color, background, style and font can be customized. Learn more about configuring colors.

Type-time Syntax error reporting

Sigasi Studio marks VHDL and SystemVerilog syntax errors while you type. It will also report broken SystemVerilog preprocessor code.

Project exploration and navigation

Sigasi Studio offers powerful techniques to explore a file or project, and navigate through it. This section covers: hovering, Occurrence Highlighting, Open Declaration and Find References.

Occurrence Highlighting

If you click on an identifier, it is highlighted. In addition, all other occurrences of the identifier that refer to the same object are highlighted. Note that this occurrence highlighting is intelligent: it is not based on the identifier’s string value, but on the object that the identifier refers to.

You can turn occurrence highlighting on or off. Click the “Toggle Mark Occurrences” icon Mark Occurrences in the toolbar.

Find References

To look for occurrences of a given identifier in different files, place your cursor on the identifier and right-click. Now select Search References.

A search window will appear on the bottom of your workbench, displaying all occurrences of the selected identifier. You can easily navigate through all occurrences by clicking the Show Next Match arrow and the Show Previous Match arrow in the search result view. Note that all occurrences are highlighted and marked with a small arrow at the left border of the editor for easy recognition.

Open Declaration You can easily navigate to the declaration of any port, signal, entity, etc. Place the cursor on the identifier, right-click and select Open Declaration. The editor immediately switches to the line that declares the object. Since this operation is so commonly used, it is assigned to the shortcut key F3.

Hyperlinks You can also navigate your code like a web browser by clicking hyperlinks. If you press and hold the Ctrl key, hyperlinks will appear in your editor. If you click the link (while holding the Ctrl key), you will navigate to the target of the link. Sigasi Studio offers following links:


To learn more about the declaration of a given identifier, hold your mouse pointer over it. After about a second, a popup shows you the name and datatype of the signal. This technique is called hovering.

In the hover pop-up, can show different kinds of information:

Since Sigasi Studio 4.1 the hovers also offer extra links that make it easy to navigate to the declaration, find references, …

Auto-complete and Content Assist

Sigasi Studio provides powerful autocompletion capabilities. This means that the tool can help you to complete identifiers and constructs as you are working on the code. Like other tools, the tool provides autocompletion based on the HDL language. However, it goes much further. It also provides autocompletion based on the design context. It can provide this additional level of intelligence as it knows all objects that have been declared in the design.

Autocompletion interface

Autocompletions may come from different sources, as will be discussed in the following sections. However, the user interface to initiate them is always the same. At any point as you are entering code, you can press Ctrl+Space and the tool will suggest appropriate autocompletions.

Based on the design context

Sigasi Studio uses its knowledge of the design to provide intelligent autocompletions that can boost productivity tremendously.

The tool knows which objects are appropriate and which identifiers are visible at any given point in the code. As you start typing and ask for an autocompletion, it will suggest the appropriate identifiers as autocompletion candidates.

Sigasi Studio provides help to autocomplete:

Based on templates

Sigasi Studio can help you to declare VHDL and SystemVerilog objects, using autocompletion based on templates. Sigasi Studio comes preconfigured with templates for all common declarations and statements, including (for VHDL):

Some autocompletions are templates which require further user input. In such a case, the editor goes into a special template editing mode after the autocompletion has been performed. You can use TAB to cycle through the items that have to be modified or completed. When done, you can press ENTER to return to the normal editing mode. The cursor will be placed at an appropriate position to continue working.

You can also configure your own templates. To edit or create templates, go to Window > Preferences > Sigasi > VHDL or (System)Verilog > Templates. Here you get an overview of existing templates. You can create New… templates, Edit… existing templates or remove templates.

Templates can be exported and imported. This is useful for sharing templates with colleagues.

Other editor features

Code folding

If you work with large files, you might want to hide certain pieces of your code. This can be done with code folding. Certain constructs, such as if-statements or process-statements can be folded so that they use a single line in the editor view. You can do this by clicking the little ”-” symbol next to the statement.

Code Folding

You can also enable/disable code folding and perform other actions by right-clicking in the gutter (the small column to the left of your code) and selecting Folding.

Configure Code Folding

Rename refactoring

Right click on any identifier (VHDL or SystemVerilog) and select Refactor > Rename element (Alt+Shift+R) to change the name of the declaration and all its references. If you press Alt+Shift+R twice, you can preview the rename before applying it.

Full screen view

Double click on the editor tab to make it full screen.

Block selection

Note: In other tools, this feature may be known as column editing or column select.

Block selection is an alternative for standard (paragraph) selection. Block selection mode differs from standard selection mode in that it allows to select rectangular regions, or to set the cursor over multiple lines. Block selection is ideal for selecting vertical regions, for example a column of a table or all port names in a port map.

Block selection

To toggle between normal and block selection modes use Alt+Shift+A or press the Toggle Block Selection icon in the tool bar.

Structured selection

Structured Select enables you to select VHDL or SystemVerilog code, based on its syntactic structure. (Screencast: “Select code, based on its structure”)

Show whitespace

You can turn showing whitespace markers on or off by clicking the “Show Whitespace Characters” icon Show Whitespace Characters in the toolbar.

Move and Duplicate lines

You can easily move lines up and down by pressing: Alt+Up and Alt+Down.

You can duplicate your current line, or the lines of the current selection by pressing: Ctrl+Alt+Down.

Configure key bindings

See Keyboard Shortcuts

Emacs/VI emulation mode

See VI and Emacs

Remove Trailing Whitespace

The action to remove trailing whitespace is hidden by default. You can access it by pressing Ctrl+3, type RTW and then select the correct action. Alternatively, you can bind this action to Keyboard Shortcuts of your preference. This action is being executed on the saved file, not in the editor. So before using this action you have to make sure your file is saved.

Customize color preferences

There are several ways to customize color preferences in Sigasi Studio.

Multiple Screen Support

You can right-click the title tab of any view and select Detach to move the view into a separate window that can be dragged to another screen. Alternatively, you can drag a view out of the current window to create a new window from it.

Once multiple windows are available, views can be dragged between screens.

Resetting the Sigasi Studio perspective will move all views into a single window.

See also this FAQ item.

Split Editor

Editor Menu

The Editor View can be split or duplicated in independent viewports that access the same file buffer. There are 3 ways to split the Editor View.

To split the editor view, go to Window > Editor and select the desired action. There are Keyboard Shortcuts to toggle the Horizontal Split (Ctrl+_) and the Vertical Split (Ctrl+{).

There can only be a single horizontal or vertical split within an Editor View. Multiple Editor Views can be cloned and re-arranged to obtain a custom layout with many views on the same file buffer.

Side-by-side Diff

Opening project files

The default way to open files in the VHDL and SystemVerilog editor, is to double click the files in the Project Explorer. But there are more methods to open files in your projects.

Open Resource

When you press Ctrl+Shift+R the Open Resource dialog opens. In this dialog you can type a name or pattern to open a specific file name.

Open Design Unit

When you press Ctrl+Shift+D the Open Design Unit dialog opens. In this dialog you can type a name or pattern to open a specific VHDL or SystemVerilog design unit name.

Open Design Unit Dialog

Note that excluded design files do not appear in this list.

Lightweight editor for large VHDL and SystemVerilog files

Sometimes you have to deal with very large HDL files such as large concatenated library files, generated files or netlists. Unfortunately the Sigasi Studio VHDL and SystemVerilog editors can not cope with huge files yet. Large files stress the interactive compiler too much to give timely feedback.

To allow you to edit large HDL files Sigasi Studio contains a lightweight VHDL and SystemVerilog editor that can handle all files without problems. This editor does not analyze your files at type time. It only offers syntax highlighting and the default Eclipse editing features. The lightweight editors will check for errors when you save your file.

The current threshold file size that is used to switch to the lightweight editor is 1 MB.

If you still want to edit large files using the Sigasi Studio VHDL editor, this can be done following these steps:

VHDL Specific

In addition to the powerful features of an Eclipse editor, the VHDL editor that comes with Sigasi Studio supports a number of advanced editing features which are specifically useful for VHDL editing. These are described in this chapter.

Code highlighting

Highlighting Classes for VHDL:

VHDL specific autocompletes

Instantiating an entity

Note: In other tools this feature may be know as paste as instantiation or port translation.

Sigasi Studio knows all entities in the design and their interfaces, and can therefore automate much of the instantiation process. At the point in the code where you normally enter the entity name, you can use autocompletion instead to suggest a list of possible entities. Upon selection, the tool will complete the instantiation with a generic map and a port map with named associations. As an initial suggestion, each actual parameter will have the same name as its formal parameter. Of course, the actual parameter names need to be reviewed and edited by the user. Therefore, the editor will go into template editing mode after the autocompletion.

Instantiating a component is similar to instantiating an entity. Note that components will only be shown if they are visible in the current scope.

Declaring a component

Note: In other tools this feature may be know as paste as component or port translation.

If you want to use instantiation based on a component (as opposed to direct instantiation) you need to associate an entity with a component. Sigasi Studio can automatically declare a component for an existing entity. At the point where you normally enter the component name, you can use autocompletion instead to show the list of available entities. Upon selection, the tool will automatically complete the component declaration.

Type Conversion

In VHDL design you need to do a lot of type conversions. Sigasi Studio’s autocomplete functionality can help you with those. Put a dot (.) after the element you want to convert, and the autocomplete suggestions will appear. The conversion functions have descriptions like “convert type” and “convert to …”.


Stuttering is an editing technique popularized by Emacs, that lets you type certain things really fast. Stuttering means that you tap a certain key twice and it expands to something more complex. For example, press the period key . twice, and the editor will expand it to a right arrow =>. Stuttering works like double clicking: if you type keys slowly, the stuttering mechanism will not be triggered.

The following stuttering keys are available:


Stuttering can be disabled or enabled throught the Enable stuttering option in the Window > Preferences > Sigasi > VHDL menu.

Smart Indentation

When you press enter, Sigasi Studio automatically adjusts the indentation of current and the new line. Depending on the content of the preceding line, Sigasi Studio will automatically increase or decrease the indentation level. E.g. an extra indent after and if-statement and remove an indent for the matching else-clause.

You can enable/disable this feature via Window > Preferences > Sigasi > VHDL by toggling the “Enter adjusts indentation on current and next line” setting.

Tabs vs. spaces: This features inserts tabs characters or spaces, according to your preferences.

See also:

VHDL code formatting

Press Ctrl+Shift+f to format your current VHDL file.

This includes:

Context based

Sigasi Studio’s formatter is context based and tries to respect the style of the author. So depending on the original source style, the formatter might make different choices.

One example is the decision to format a conditional signal assignment on one, or multiple lines. Sigasi Studio makes this decision based on the position of the first else keyword. If you put the else keyword on the first line, the formatter will put everything on one line. If you put the else keyword on a new line, the formatter will use multiple lines for the assignment.

  demo <= (others => '0') when enable = '1'
    else (others => '1') when input = '1' -- else on new line
    else (others => 'X');

Note about broken code: If your VHDL source file contains syntactical errors, the formatter can not always figure out an appropriate formatting. For this reason the formatter is programmed to stop applying (whitespace) changes when unsupported syntax errors are encountered.


You can set your preferences for Tabs or spaces under Window > Preferences > General > Editors > Text Editors > Insert Spaces for Tabs.

Other preferences for code formatting are part of Sigasi Studio XL . You can configure them at Window > Preferences > Sigasi > VHDL > Formatting Configurable settings currently include:

Correct indentation only

Sigasi Studio can also correct the indentation of your code without making any other changes. Inside a VHDL editor, open the context menu and click Source > Correct Indentation, or hit Ctrl+I. This only changes whitespace at the start of you lines.

If you select code first, only the code in the selection will be indented.

Disable formatting in defined regions

You can disable the formatter for defined regions in your VHDL source files by enclosing them by off and on tags:

Format code on save

You can configure Sigasi Studio to automatically format your VHDL files when you save your source files via Preferences > Sigasi > VHDL, next enable Enable code format on save.

Format project

[Only in Sigasi Studio XPRT]

Since Sigasi Studio 4.5 you can format (System)Verilog and VHDL files without opening them in the editor. Right click a project, folder or file and select Source > Format.

Note that the option is only available for files that are part of the build.

SystemVerilog Specific

In addition to the powerful features of an Eclipse editor, the SystemVerilog editor that comes with Sigasi Studio supports a number of advanced editing features which are specifically useful for SystemVerilog editing. These are described in this chapter.

Initial preprocessor definitions for SystemVerilog projects

Since Sigasi Studio 3.6 you can configure definitions that are set before other files in the project are processed. Right click your project and select Properties > (System)Verilog Preprocessor.

The code in the Initial preprocessor definitions field is preprocessed before all other SystemVerilog code in your project. This allows you to, for example, set global defines without an explicit include statement.

Verilog version

You can configure the Verilog version via Window > Preferences > Sigasi > (System)Verilog and select whether *.v files are treated as Verilog or SystemVerilog. *.sv files are always treated as SystemVerilog.


Press Ctrl+Shift+F to format your current SystemVerilog file.

The current formatter implementation corrects indentation only.

Smart Indentation

When you press enter, Sigasi Studio automatically adjusts the indentation of current and the new line. Depending on the content of the preceding line, Sigasi Studio will automatically increase or decrease the indentation level. E.g. an extra indent after a module and remove an indent for the matching endmodule.

You can enable/disable this feature via Window > Preferences > Sigasi > (System)Verilog by toggling the “Enter adjusts indentation on current and next line” setting.

Tabs vs. spaces: This features inserts tabs characters or spaces, according to your preferences.

See also:

SystemVerilog Preprocessing/Macros

When you hover over a SystemVerilog preprocessor directive (e.g. include ...), Sigasi Studio presents you the preprocessed text. This hover also shows you, at the bottom, a convenient link to open the Preprocessor View.

In the Preprocessor View, you can preview the expanded version of your preprocessed SystemVerilog source files.

You can configure the include paths of your SystemVerilog projects in the (System)Verilog Preprocessor Property page. You can open this page by right clicking your SystemVerilog project and selecting Properties > (System)Verilog Preprocessor.

You can specify multiple include paths by separating them with a ;. All paths are relative to the project folder. You can add the main project folder as include path by entering ..

You can also add an include path by running the Quick Fix on `include errors.

On the (System)Verilog Preprocessor Property page you can also declare Initial preprocessor definitions.

Ctrl+Click on `defines (or F3) will lead you to the corresponding declaration. Autocomplete will also offer you a list of all visible `defines.

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Mixed language projects

[Only in Sigasi Studio XL]

You can create mixed language projects by adding both VHDL and Verilog or SystemVerilog support to your project: right click your project and select Configure > Add VHDL support and Configure > Add (System)Verilog support.


In mixed language projects you can navigate from instantiation statements to the matching entity or module. This works for both VHDL entity instantiations in (System)Verilog code and (System)Verilog module instantiations in VHDL code. You can also open the declaration of ports and generics/parameters in mixed instantiations.

Other supported features:

Screencast : Mixed languages: instantiating Verilog in VHDL code

Using two languages in Sigasi Studio

If you don’t have the correct license for mixed language projects, you can still create your designs using two separate languages. In this case, choose your main language and enable support for this language (in this example: VHDL). Now, the files in the other language (in this example: Verilog) can still be in your project. You can still edit them and you even get Sigasi Studio support inside any one Verilog file. What is disabled now are the references from and to any Verilog files, but they work within a single Verilog file.

If you want to instantiate a (System)Verilog module in VHDL you need to work with a component declaration so that the VHDL part know the interface of you (System)Verilog module.

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Opening Files

Opening Files from the Command Line

You can call Sigasi Studio from the command line to open files. Just run sigasi yourFile.vhd. You can also drag and drop files on the Sigasi Studio icon to open them.

You can specify a linenumber by appending +yourLineNumber to the command line. For example: sigasi test.vhd +10 will open test.vhd at line 10.

You can also specify the project location with the -p <project path> parameter. If the specified project was not open in the workspace yet, this will import and open the project in the workspace.

Note that the VHDL file you specify on the command line has to be in an open Sigasi project to enjoy all of Sigasi Studio’s powerful editing and navigation features. If the file you open from the command line is not in a Sigasi Studio project, Sigasi Studio opens the file as an external file. This is nevertheless really handy for quick edits.

This feature enables you to configure Sigasi Studio as default editor for other EDA tools.

Note You could get a firewall warning when you start Sigasi Studio because Sigasi Studio opens and listens to a port (4444 by default). This is necessary for the communication between the running Sigasi Studio instance and the command line executable. Configure your firewall to allow Sigasi Studio access for opening this port.

Eclipse Plugin

Eclipse plugin users can also use this feature but need to specify a few more command line options. You have to type eclipse -application instead of sigasi. For example: eclipse -application test.vhd +10 will open test.vhd at line 10.

Other command line options

You can add some extra parameters to Sigasi Studio to modify the behavior.

External Files

You can edit VHDL files without setting up a project. When a file that doesn’t belong to a project is opened in Sigasi Studio, this file is called an external file and it will be opened in single file mode.

Single file mode is a limited environment in which not all Sigasi Studio features are available. Navigation only works within a file. For that reason missing declaration are not flagged as errors.

There are several ways to open VHDL files:

If the file belongs to a project, Sigasi Studio will open the file as part of that project. If not Sigasi Studio opens the file as external file.

In general, if you want to benefit from all of the Sigasi Studio features, you should set up a proper project.

Setting up Sigasi Studio as Default Editor


To configure Sigasi Studio as default VHDL editor in Windows:

Repeat this procedure for *.vhd files and for *.vhdl files.



Sigasi Studio as default editor in KDE


Sigasi Studio as default editor in Gnome

Mac OS X

When I double-click a VHDL file, I want it to open with my favorite VHDL editor. Sigasi Studio, obviously.

Here is how to set this up in Mac OS X:

Repeat this procedure for *.vhd files and for *.vhdl files.

Setting the default application for VHDL files

Altera Quartus II

In Altera Quartus II, open the preferences page in Tools > Options > General > Preferred Text Editor.

Configuring Sigasi Studio as default VHDL editor in Altera Quartus

As command-line options, you should have %f +%l -p %p. Optionally you could add -noSplash to skip the splash dialog.

Xilinx Vivado

You can configure Sigasi Studio to be the preferred editor for Xilinx Vivado.

  1. In Xilinx Vivado, click Tools > Settings…
  2. Open the Tool Settings > Text Editor tab
  3. Locate the Current Editor drop down menu and instead of ‘Vivado Text Editor (default)’ select ‘Custom Editor…
  4. If needed click the button and in the pop-up dialog enter: <path to Sigasi Studio>/sigasi.exe [file name] +[line number]
  5. Click OK to close the dialog and OK to close the Settings window.

Configuring Sigasi Studio as default editor in Xilinx Vivado menu
Configuring Sigasi Studio as default editor in Xilinx Vivado

Extra steps for the Sigasi Studio plugin on Windows

If you use the Sigasi Studio Eclipse plugin on Windows, you might need to take some extra steps before you can open files from Vivado in Sigasi Studio.

Make sure to close Eclipse before making the changes below.

The first time you might need to pick a workspace and enable the use this as default and do not ask again option.

Xilinx ISE

To configure Sigasi Studio as default VHDL editor in Xilinx ISE:

  1. In Xilinx ISE, Click Edit > Preferences and ISE General > Editors
  2. Select Custom instead of ISE Text Editor
  3. If Sigasi Studio is on your path enter sigasi.exe $1 +$2 (Windows) or sigasi $1 +$2 (Linux). If Sigasi Studio is not on your path, use the absolute path instead. If there are spaces in this path, you need to enclose the path in curly braces . For example:c:\\My\ Applications\sigasi\sigasi.exe $1 +$2.
Configuring Sigasi Studio as default VHDL editor in Xilinx ISE

If you now open any VHDL file in Xilinx ISE, Sigasi Studio will automatically open the selected file.

You can find more info on configuring Xilinx ISE to work with external editors in the Xilinx documentation.

HDL Designer

To configure Sigasi Studio as external editor in HDL Designer:

  1. In HDL Designer, click Options > Main
  2. Click the Text tab
    Main Settings Text 1
  3. Press the Setup… button in the Editor section to open the Editor Command Setup dialog.
  4. Fill the Name, Command and Arguments sections as shown.
    Editor Command Setup 1
  5. Click the Add button to add Sigasi Studio to the list of available editors.
    Editor Command Setup 2
  6. Press OK to close the dialog.
  7. Press the Setup button in the HDL Viewer section and repeat this procedure from step 4.
    Editor Command Setup 3
  8. You now can select the Sigasi entry in the list box for the Editor and HDL Viewer sections.
    Main Settings Text 2
  9. From now on you can double click on a file or a line in a file - for example by selecting an architecture or an entity - and Sigasi Studio will open the file at the correct location.

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Linting and Quick Fixes

In addition to syntax validation, Sigasi Studio also checks your code for semantic problems (Linting, or Linter checks). Some of these problems can be automatically resolved with Quick Fixes. Both syntax checking and linting happen at type-time: new markers appear as you are typing your code.


VHDL code Lint is defined as code that is strictly correct according to the language definition, but still suspicious or problematic. Sigasi Studio has a built-in VHDL linter, which provides info about code lint in the design.

Marker Icons

Configuring the Severity Level

The Sigasi Studio VHDL linter has reasonable defaults for the severity level of reported lint problems. However, the severity level of certain classes of lint is configurable for additional flexibility. The configuration interface is available in Window > Preferences > VHDL > Errors/Warnings.

Configuring the severity of Sigasi Studio linting checks

You can also configure the severity level per project.

Suppressing warnings

Specific warnings can be suppressed in your code by adding a @suppress comment (-- @suppress for VHDL, // @suppress for SystemVerilog), on the same line as the warning.

You can limit the suppression to a specific warning by putting a prefix of the warning message between quotes after @suppress. Sigasi also recommends adding a reason why the warning was suppressed by adding an extra comment after @suppress:

<line with warning> // @suppress "Warning message prefix" Reason why warning is suppressed

Since Sigasi Studio 4.2 the @suppress comment also suppresses Errors. Since Sigasi Studio 4.3 warnings have a quickfix to automatically add the @suppress comment with a matching warning message prefix.

No Linting for Common Libraries

Common Libraries are considered to be production ready libraries. Linting is skipped for all files in the Common Libraries folder.

Quick Fixes

Some of the VHDL lint problems can be automatically resolved with Quick Fixes. These problems have markers annotated with a lightbulb icon (like ). To trigger a Quick Fix, click the problem marker or press Ctrl-1 and select the Quick Fix.

List of (System)Verilog code rules

The table below lists the (System)Verilog code rules that can be checked automatically by Sigasi Studio. The availability of code rules depends on the license requirements.

LicenseQuick FixDescriptionID
STFile encoding differences between including and included files
XPRTNull loops1
XPRTCheck Naming Conventions2
XPRTDisallow ‘reg’ datatype3
XPRTVHDL keyword as module name7

List of VHDL code rules

The table below lists the VHDL code rules that can be checked automatically by Sigasi Studio. The availability of code rules depends on the license requirements.

LicenseQuick FixDescriptionID
STDeclaration could not be found
STDuplicate declarations
STSignal/variable assignment operator
STCase statement does not cover all choices
STMissing enumeration literal in case statements
STInstantiation statement validation
STLibrary validation
STSubprograms in packages (e.g. function body in a package, rather than in the package body)
STMissing return statement in function bodies
STCorrect attribute entity class in attribute specifications
STC-style equality and inequality operator (= and /= vs == and !=)
STVHDL 2008 features in VHDL 93 mode (Learn about choosing your VHDL version)
STPort/Generic lists cannot be terminated with a ‘;’
STPort/Generic maps cannot be terminated with a ‘,’
CRDeprecated IEEE packages8
CRNon-standard packages37
CRA process must either have a sensitivity list or contain one or more wait statements38
CRThere has to be a whitespace before physical units47
CRSuperfluous library clause49
CRLibrary is not available Configure Altera, Xilinx, ModelSim and VUnit libraries50
CRFind unused declarations55
CRBitstrings may only contain std_logic metavalues57
CRDuplicate, conflicting design unit names64
CRFind unused ports67
CRFind unused generics68
CRFind incomplete sensitivity lists72
CRFind superfluous signals in sensitivity lists73
CRReport encrypted files84
CRFind duplicate signals in sensitivity lists85
CRIncorrect use of keyword all184
XLNull range: The left argument is strictly larger than the right1
XLCase alternative contains redundant choices12
XLCase statement contains all choices explicitly. You can safely remove the redundant ‘others’13
XLInfinite loop. Loop is missing a wait20
XLNull range: The left argument is strictly smaller than the right26
XLUnbound component instantiations48
XLFind dead states in state machines71
XLFind dead code (unreachable statements)79
XLDetect signals and variables that are never written88
XLDetect signals and variables that are never read89
XLNone or multiple matching entities for component90
XLCheck naming conventions92
XLIncomplete port map or generic map94
XLVector width in assignments and port maps144
XLAll references must have the same capitalization as their declaration163
XLCheck for positional associations in instantiations164
XLInvalid port associations (incompatible port modes in instantiations)169
XLOrder of generic and port associations177
XLIncorrect component name in configuration180
XLIncorrect instantiation statement label in configuration181
XLMissing or incorrect binding indication182
XLIncorrect name in binding indication183
XLRedundant boolean equality check with true185
XLBoolean equality check with false186
XLCheck for component/entity mismatch187
XLHeader comment check188
XLFilename must contain primary unit name189
XLEmpty loop statement190

Detailed explanation of code rules

Dead Code lint

Dead code is code that is does have any effect in your simulation or synthesis. Examples of dead code are signals that are never used, or conditions that are never triggered.

Dead code does not bother the simulator nor the synthesis tool. However, it consumes mental energy of anybody reading the code. People will try to figure the puropose of a given statement and it may take a while before they realize that they are dealing with dead code. This makes it more expensive to review code and to reuse code. In general, dead code is a form of technological debt that should be avoided.

Sigasi Studio flags some kinds of dead code:

For unused declarations, there is also a Quick Fix to help you remove unused declarations fast.

Deprecated IEEE Packages, Non-Standard Packages

Some packages are widely spread, but were never standardized by IEEE. Different vendors have shipped different versions, with incompatible implementation. These packages should not be used and are flagged as Deprecated IEEE packages.


Instead, use the standard ieee.numeric_std package.

The package ieee.std_logic_misc has the same problem of not being standardized by IEEE. Contrary to the packages above, there is no consensus on how to replace this package.
Sigasi Studio flags this package as Non-standard package.

Read more in Deprecated IEEE Libraries.

Incomplete Port Maps and Generic Maps

Available since Sigasi 2.25

Sigasi Studio warns about port maps and generic maps that are not complete:
Port map is using default values. Missing optional actuals: yourport

Input ports and generics need to be be assigned in your instantiation statement, if they don’t already have a default value. If you don’t do this, you are writing illegal VHDL. Sigasi Studio will mark an error, and so will all other tools.

Input ports and generics with a default value, as well as output ports do not need to be assigned explicitly. However, this is often not intended. For that reason, Sigasi Studio can warn you about this.

Positional Association in Instantiations

Available since Sigasi 2.30

Most VHDL designers prefer named associations in port and generic maps in instantiations. This makes it a lot easier to spot wrong connections. By default Sigasi Studio warns when positional associations are used. You can change the severity of this check via Preferences > Sigasi > VHDL > Errors/Warnings in the Instantiation statement valiadation section.

Quick Fix for Third Party Libraries

If you are using vendor libraries from Altera or Xilinx (ISE or Vivado), you do not need to set up these libraries by hand. Sigasi Studio has a Quick Fix to do this for you.

The library statement that tries to import a missing library (like altera) will be have a yellow warning marker next to it. Click this marker and select Configure library altera. If the path to your Altera Quartus (or Xilinx ISE) installation is not yet set, Sigasi Studio will ask to set the path now. You can always change these paths in Window > Preferences > Sigasi > Toolchains. Note that for the Xilinx libraries we only map the packages with the component declarations. By default all entity and architecture declarations are not mapped (excluded). This significantly reduces the time for a clean build. If you use direct entity instantiations, you can easily map the entities you need.

Redundant “others”

If a case statement contains all the possible choices (usually in an enumerated datatype), you can safely remove the when others clause. Sigasi Studio warns about this:

Case statement contains all choices explicitly. You can safely remove the redundant others.

There is some debate on this coding rule. However, the vast majority of synthesis tools do not take the others into account if all choices are enumerated. If the synthesis tool is set up to generate fault-tolerant hardware, the fallback state is the same as the reset state (for most synthesis tools). Check the manual of your synthesis tools and run some experiments. For more information, see VHDL case statements can do without the “others”.

Sensitivity List

VHDL requires a sensitivity list for each process (or wait statements in the project).

Since VHDL-2008, you can write process (all) to make sure you have all signals in the sensitivity list. In all earlier versions, incomplete sensitivity lists can cause unexpected behavior. That is: your simulation results may be different from your synthesis results. Most synthesis tools ignore your sensitivity list. In traditional workflows, only the synthesis warnings will give you a hint that your sensitivity list is incomplete. This report will be available only hours or even days after you have finished typing your code. Flagging this problem earlier saves time and lets you catch the problem early.

Sigasi Studio can warn about problems with your sensitivity list:

Superfluous Library Clause

The VHDL language reference manual states that:

Every design unit except package STANDARD is assumed to contain the following implicit context items as part of its context clause:

    library STD, WORK;
    use STD.STANDARD.all;

Hence, any extra library statement that includes STD or WORK is pointless, as is any use clause that includes std.standard.all. Hardly anybody would type the use clause, but quite some people start all of their files with two extra library clauses. Sigasi Studio flags this as warning.

Dead Code (unreachable code)

If the Sigasi Studio analyzer can determine that a condition is always false, it will mark the if-statement because it contains dead code.

Null Range (empty range)

In VHDL, you can use ranges with to and downto. But, if you use the wrong direction, you get an empty range, which is usually not what you want: 7 downto 0 is a range of eight. 7 to 0 is an null range. We have a lint check that warns about this, even if you use constants (or some simple arithmetic).

Space Before the Physical Unit

If you type a numeric literal with a physical unit, there should be a space between the number and the unit.

    T := 25ns; -- ILLEGAL, but accepted by ModelSim
    T := 25 ns; -- OK; according to VHDL language standard

Mentor Graphics’ ModelSim and QuestaSim accept the former (illegal) version. As a result, some VHDL designers got used to writing the incorrect version, producing code that is not portable to other simulators. Sigasi Studio accepts the ModelSim-style physical literals, but warns about this.

Capitalization of Identifiers

Although VHDL is not case sensitive, it is recommend to always use the same capitalization when referring to the same declaration. Since version 2.30, Sigasi Studio warns when the capitalization of a reference differs from the capitalization of the declaration. Because external libraries can have different code styles, this linting only checks references in the same library as its declaration.

Since Sigasi 2.31 this can easily be fixed with a Quick Fix.

Since Sigasi Studio 3.6 all capitalization issues in a file can be fixed in one click.

Naming Conventions

On the Navigation conventions preference page (Window > Preferences > Sigasi > VHDL/(System)Verilog > Naming conventions) you can configure patterns to check correct naming of your VHDL and SystemVerilog identifiers. Patterns are configured with Java regex syntax.

Only names with a specified pattern are checked. Empty patterns are omitted.

Example: to enforce a style where all variables have a _v suffix, you would specify .*_v pattern in the Variable name field.

Vector width in assignments and port maps

Sigasi Studio checks the vector size in assignments (Since Sigasi 2.28) and port maps (Since Sigasi Studio 3.1). This check works at type-time and takes the (symbolic) value of generics into account.

Sigasi Studio will not take into account the value assigned to a generic in instantiations. The reasoning behind this is explained here.

Order of associations

Sigasi Studio gives a warning when the order of generics or ports in a map differs from the original generics or ports declaration order.

Check for component/entity mismatch

Sigasi Studio gives a warning if a component declaration is not equal to its matching entity. You can easily fix this by applying the quick fix.

Check header comment

Sigasi Studio can check that the header comment matches a specified pattern. A header comment is the comment that starts at the first character of your file (no leading whitespace).

The check can be enabled in Preferences > Sigasi > VHDL > Naming conventions. The pattern can be set on the same page.

Since Sigasi Studio 4.4, the raw string of the header comment is checked to allow for maximum compliance checking. This means that when a new line is matched, users should use \r?\n or the newly introduced \\R to make sure the naming conventions work on all platforms.

Check header comments

Check that filename contains primary unit name

Sigasi Studio can check that the filename contains the name of at least one of the design unit names inside that file. Note that this check is ignored by default. You can enable it in the VHDL Errors/Warnings preference page (Style Validation > Filename must contain primary name).

Check file name

Project specific Linting settings

Severity of Linting checks

The default way to configure the severity of the Sigasi Studio linting checks is to set their severity in the Errors/Warnings preference page. You can override these setting by creating a settings file for your projects.

In each project, you can override the coding rules settings. You can override rules for the entire project, for folders in the project, or for individual files.

Errors/Warnings property page

To configure the severity level, right click the project (or file or folder) in the Project Explorer and select Properties > VHDL Errors/Warnings or Properties > SystemVerilog Errors/Warnings.

Configure linting severity per project

Project settings are stored in this settings file:

    ${project location}/.settings/com.sigasi.hdt.vhdl.linting.prefs

You can search for a specific rule, by using the search field at the top of the property page.

Search for a specific rule

Manual configuration

To configure the severity of validations, add a line for each validation:

    ${validation id}/severity/${path}=${severity}

Where ${validation id} can be

Validation ID numbers are listed in the List of VHDL code rules and can also be found in the Project Properties under VHDL Errors/Warnings.

Where ${path} can be:

Where ${severity} can be:

Whitespace must be escaped with a back slash (\). You can add comments with #.


    72/severity//Folder\ name/Extra\ folder=INFO

Naming Conventions per project

While Naming Conventions can be configured globally for a workspace, they can also be defined per project. The project-specific Naming Conventions are stored in this settings file:

    ${project location}/.settings/com.sigasi.hdt.vhdl.linting.prefs

The validation ID for Naming Conventions is 92. Therefore all lines that configure Naming Conventions should start with 92 and are of this format:


Valid ${identifier} values are:


Naming Conventions can be restricted to a specific library using ${lib}. Possible values are:

The pattern that defines the Naming Convention is set in ${convention}. Patterns are configured with Java regex syntax.

Naming Conventions for a project and setting the severity of the linting checks are configured in the same settings file. Examples:


Errors in the patterns will be reported in the log file: Help > Open Log.

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Tool Integration

Sigasi Studio supports a number of ways to work with external tools such as simulators. Different techniques offer varying degrees of flexibility and automation.

Most people will want to set up their external compilers so that Sigasi Studio can use them to compile and start simulations.

Another way to compile your project is to export your project to a CSV (comma separated values) list of all the files in your project, in the correct compilation order. Learn more about how to export your project’s file list.

The third, and more advanced way of working with compilers or simulators is to use the standard Eclipse mechanisms of builders and external tools.

By creating a builder, you can arrange for an external tool to be run automatically when a Sigasi Studio project is rebuilt. By default, this happens each time you save a file. External Tools Configuration allow you to call any program or script from within the Sigasi Studio GUI. You have to write and maintain the scripts yourself, but you have complete flexibility as to what is in the scripts.

External Compilers

If you have a simulator or lint tool installed, you can use this for two purposes:

  1. Save-time Compilation: Compile and check your files each time you save. Any errors or warnings will show up in the file, on the line number of the problrem
  2. Launch Simulator: Start the simulator in its own window, ready to run a simulation.

Learn about which external compilers are supported and how to Configure external compiler.

Launch simulator

If an external compiler is enabled, you can also start a simulation from Sigasi Studio. You can start a simulation by first selecting your top level in the Hierarchy View. Next click the Simulate button in the hierarchy view to launch the simulator gui with an elaborated design ready for simulation. Sigasi Studio opens a new console for each simulation launch. You can terminate a simulation by clicking the Stop icon .

When you launch a simulation, Sigasi Studio opens a new console in the Console View You can switch between different consoles by clicking the icon console display-icon.

Configure external compiler

You can configure the external compiler settings by clicking Window > Preferences > Sigasi > Toolchains. There is a sub-page for each supported toolchain. Before you can enable a toolchain on the main page, you must specify its installation path. Clicking Restore Defaults on a Toolchain page will automatically fill in the installation path if your toolchain is installed on a default location. After you press Apply, you can select your toolchain on the Sigasi > Toolchains page.

For some toolchains you can specify extra command line arguments. Note that these preference pages support Eclipse Variables which allow you to more easily share settings in a team.

Environment variables are supported too. If you want to use the $HOME environment variable, you can call this variable by typing ${env_var:HOME}.

List of toolchains

By “toolchains”, we mean any tool or set of tools that processes VHDL or Verilog code, and that is supported by Sigasi Studio. At this time, external compiler include simulators and lint tools, but in the future it could also include synthesis tools.

For each toolchain Sigasi Studio can support any combination of the following:

Currently the following external compilers are supported:

Toolchainsave-time compilationstart simulation
Aldec Riviera-PROtruetrue
Aldec Active-HDLtruefalse
Aldec ALINTtrue(run elaboration checks)
Aldec ALINT-PROtruefalse
Altera Quartus IIfalsefalse
ModelSim / QuestaSimtruetrue
Xilinx ISEtruetrue
Xilinx Vivadotruetrue
Cadence Incisivetruefalse
OneSpintrue(run elaboration checks)

For information on where to obtain free HDL simulators, see this section in our FAQ.

Save-time compilation

Sigasi Studio can use an external VHDL or Verilog compiler for additional code validation. At this time, Sigasi Studio supports:

Catching bugs earlier is cheaper than catching them late. Traditionally, the first errors are found when the hardware designer decides to run a simulation. At this time, the simulator’s compiler tool will detect errors and fail. At Sigasi we think that this is too late. Problems should be detected as soon as possible.

Sigasi Studio adds two extra layers of error detection to catch problems earlier. First, there is the type-time error detector. As soon as the designer writes an error, it is marked in the text much like a spell checker in a word processor. Second, as soon as you save a file, Sigasi Studio calls the external compiler for further analysis. All errors that the external compiler finds are marked inside your file, so that you can find and fix them easily. Sigasi Studio intelligently controls the external compiler incrementally and only recompiles design files that need recompilation.

All output from external compilers is logged in Sigasi Studio’s console view for your convenience. Paths to your design files are automatically converted to hyperlinks to ease naviation.

The table below lists some examples of VHDL errors that are detected in Sigasi Studio at type time, at save time and with the external compiler integration.

CheckType timeSave timeSave time compile
Syntax errorsyesyesyes
Undeclared signalsyesyesyes
Multiple filesnoyesyes
Data type mismatchnonoyes
Multiple driversnonoyes


Libraries are fully supported. But note that Sigasi Studio does not send Common Libraries to the external compiler for compilation. These libraries are expected to be pre-compiled. Contact if you want to add more libraries to this list.

If your project root contains a modelsim.ini file, Sigasi Studio will add this file to the vcom command with -modelsimini. This allows you to configure custom settings for Mentor’s vcom.

External Tools Configuration

Select Run > External tools > External Tools Configurations to get started, or use the icon.

To create a new configuration, first select Program, then click .

Enter all necessary information to start your external tool:

You can test your tool configuration with the Run button.

The following example screenshot shows how to set up configuration to run a script from within Sigasi Studio.

The following example screenshot shows how to set up a configuration to run make clean on a Linux machine.

To run the external tool just select the configuration from the dropdown menu on the -icon. You can rerun the last configuration by simply clicking .

Variables in Arguments

In the arguments field you can use variables, which are automatically expanded when the external tool is run. This allows you to do things like adding the currently selected file in the file explorer as an argument for an external tool configuration (${resource_path}).

Sigasi Studio adds following variables for VHDL and (System)Verilog projects:

Variable NameDescription
${library:<argument>}Get the library name of <argument>. For example, to the get the library of the currently selected resource use ${library:${resource_path}}
${vhdl_toplevel}Get the name of the current top level name

Creating a Builder

An external tool configuration as described in the previous section makes it easy to run an external tool, but you still have to do so explicitly. For some programs, such as the make utility, it makes sense instead to do this automatically upon a change in your project. This functionality can be accomplished by a builder. We will show how to create a builder for a Modelsim Makefile as an example.

To create a builder, right-click your project and select Properties > Builders.

Click New… and the builder configuration window will pop up:

You will be asked to select a configuration type: select Program.

Next, configure the builder in a configuration window pop up window:

With the default settings the ModelSim Makefile will only be run during a manual build or after a “Clean”. To make sure Sigasi Studio runs make every time you save a change to a file, click the Build Options tab and check the During auto builds checkbox.

After configuration, the new builder will appear in the builder list.

When you close the builder configuration dialog windows, the new builder will automatically be run. In our example of a Modelsim Makefile, Modelsim’s messages will appear in the console view.

For the specific case of Modelsim, warnings and error messages in the console are made clickable. When you click a message, the corresponding location will automatically be opened in the Editor view.

You can add as many extra builders as you want. This can be useful for additional linting tools or code generators.

Altera Quartus II integration

If you are using Altera Quartus II 12.1 , you can use Sigasi Studio as preferred HDL editor.

If you use the Sigasi Studio/ Altera Quartus II integration, you can easily open VHDL files by double clicking on them in Quartus II. Sigasi Studio will be aware of the entire Quartus II project, so that you can perform project-wide searches and navigation actions in Sigasi Studio. Furthermore, if you add or remove files in the Quartus II project, these changes are automatically applied in Sigasi Studio.

Note: If you want to set up a project independent of Altera Quartus II, please read the documentation on setting up a project.

Setting the preferred editor

While importing a Quartus Project in Sigasi Studio, you have the possibility to configure Sigasi Studio as preferred editor in Altera Quartus II. This offers the ability to open files in Sigasi Studio from within Quartus.

Open a Quartus II Project in Sigasi Studio

After you have configured Sigasi Studio to be the preferred editor in Quartus II, you can open files by double clicking on them in Quartus II.

Sigasi Studio will import entire Quartus II project and your file will open in the Sigasi Studio editor view. If you make changes to your Quartus II project (like adding or removing files), these changes are reflected in Sigasi Studio as well.

The first time you import your project, it may take a few minutes. After that, you can leave Sigasi Studio open and double-click other files in Quartus II to open them in the Sigasi Studio editor view.

If your Quartus II Project File (.QPF file) contains a reference to a file that does not exist, Sigasi Studio will show an icon for that file with the broken link icon .

Quartus II Preferences

The first time you import a Quartus II project, Sigasi Studio will ask for the Quartus II installation location. Sigasi Studio needs this path to find the Quartus II libraries. You can change the Quartus II installation location by selecting Window > Preferences > Sigasi > Toolchains.

Add files to your Quartus II project in Sigasi Studio

To add a file to your Quartus II project, you can use the default New VHDL file wizard of Sigasi Studio (File > New > VHDL File).

Add a new VHDL file to a Altera Quartus II project in Sigasi Studio

Note that Quartus II does not automatically update its UI after you add files to your project. In order to update the files list, you should run a work flow action in Quartus II, like starting a compilation.

Xilinx integration

Setting the preferred editor

To open the Sigasi Studio editor from Xilinx, you first have to configure Sigasi Studio as preferred editor in Vivado or ISE.

Importing Xilinx Projects in Sigasi Studio


The process of importing a Xilinx Vivado project is explained in Generating a Sigasi project from a Vivado project.


The process of importing a Xilinx ISE project is explained in Importing a Xilinx ISE project in Sigasi.

Xilinx Preferences


You can change the Xilinx Vivado installation location by selecting Window > Preferences > Sigasi > Toolchains > Xilinx Vivado. Sigasi Studio needs this path to find the Xilinx Vivado libraries.


You can change the Xilinx ISE installation location by selecting Window > Preferences > Sigasi > Toolchains > Xilinx ISE. Sigasi Studio needs this path to find the Xilinx Vivado libraries and to run the ISim compiler and simulator.


You can export a list of all HDL files in your project, sorted in the correct compilation order. You can use your own simple scripts to manipulate such list and run any EDA tool, including simulators, synthesis and linter tools.

To export a comma separated value (CSV) list of files in your project, right-click your project and select Export…. In the Sigasi category, select CSV File. Then select the project you want to export. As a result, you get a file named compilation_order.csv, which lists the VHDL files in your project in a valid compile order.

Example (for the tutorial project):

work, dut.vhd
work, clock_generator.vhd
work, testbench.vhd

This file will use relative paths, except when the file is on a different drive (on Windows).


You can also configure Sigasi Studio to auto-export this CSV file, every time the dependencies change.

Right click on the project you want to auto-export in the Project Explorer, and select Properties and Sigasi auto export.

Auto export CSV file with dependencies

If you do not set a fixed top level name (i.e. empty top level name in the property page), Sigasi Studio will use the current top level in the Hierarchy View as input. Note that this only works if the top level belongs to the selected project.

This information is stored in .settings/com.sigasi.hdt.vhdl.ui.prefs in your project.

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Sigasi Studio VUnit Integration

[Only in Sigasi Studio XPRT]

VUnit is an open source unit testing framework for VHDL and SystemVerilog. VUnit helps you to write tests more easily and run them frequently.

Sigasi Studio can help you manage VUnit projects and enables you to run and inspect test results straight from the IDE.

When you import a VUnit project or add VUnit support to an existing project, Sigasi Studio runs VUnit in the background and automatically adds the correct libraries - as specified by the VUnit script - to your project. It also shows error markers in the VUnit script ( if anything goes wrong.

VUnit project

VUnit project setup in Sigasi Studio

Import VUnit Project

To import an existing VUnit project, click File > Import… > Sigasi > Import a VUnit project. Next, select the VUnit script ( and the location for the Sigasi Project.

Add VUnit support to an existing Sigasi project

You can also add VUnit support to an existing project: Right click your project and select Configure > Add VUnit support. Next, select an existing script or let Sigasi create an example script.


For SystemVerilog projects you need to manually add the VUnit include files to your projects: * Right click your project, select New > Folder > Advanced > Link to alternate location and add VUNIT/verilog/include as location. * Use the quick-fix on the failing `include "vunit_defines.svh" to add the include folder to the include paths.

Add verilog include path

Run VUnit Tests

There are multiple ways to run VUnit tests in Sigasi Studio:

Run VUnit VHDL tests

Inspect VUnit Test Results

When you run VUnit tests in Sigasi Studio, the VUnit view is opened. This view presents a convenient way to inspect the test results.

VUnit SystemVerilog Example

You can also open the Console View to inspect the entire VUnit output.

VUnit console view

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Documentation Generation

The Sigasi Studio documentation generator makes the documentation process easier by automatically extracting information from your HDL source files. The biggest advantage is that there is only a single source for both your design and your documentation. While this gives no guarantee for the design staying in sync with the documentation, it certainly makes it easier.

The Sigasi documentation generator has following advantages:

Export Documentation

You can export documentation for the entire project or a specific toplevel by clicking the save icon on top of the Documentation View or via the Export… menu.

The result is saved in the sigasi-doc folder in the root of your project.

Since Sigasi 2.27 this export also saves the DocBook source code, if you have a Sigasi Studio XPRT license. This enables you to customize the pdf generation flow to your liking. Users without a Sigasi Studio XPRT License can also export a pdf, but it will contain a watermark.

Since Sigasi Studio 4.5 it is possible to export to HTML directly in addition to the pdf export. There are 3 options to export the documentation.

All errors are logged to the console view.


The exported documentation also includes statemachine and block diagrams. If you created custom graphics configurations for one or more of your diagrams, these will be used instead of the default diagrams.

If you have multiple graphics configurations for the same diagrams, the alphabetically first one is used.

Customize templates

The templates used for the pdf documentation can be copied and modified in the workspace so that template customizations are not overwritten by updates of Sigasi Studio.

Comment Association

Comments in HDL code are used to add extra information or documentation to that code. Sigasi Studio uses certain rules to determine which comment belongs to which code. This is important for documentation hovers, refactoring, formatting,… Which comment belongs to which exact code is subjective.

Sigasi Studio associates comments with HDL declarations with following rules:

The association rules are illustrated in the image below:

comment association rules

The Formatter and Structural select respect (and fix) comments according to the association rules.

Special cases

Comment markup with MarkDown

VHDL and SystemVerilog comments are processed with a Markdown processor. This allows to add markup (e.g. bold, code, paragraphs, hyperlinks,…) to comments. This results in nicer hovers and documentation.

MarkDown in comments

In hovers the complete Markdown syntax is supported. For documentation generation following features are supported:

Sigasi Studio 4.6 added support for Fenced Code blocks in comments. This enables you to add text to the documentation without Markdown rendering. To add a comment verbatim to the documentation, surround it with with triple back ticks: ```<verbatim comment>```

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Graphics Configuration

[Only in Sigasi Studio XPRT]

The BlockDiagram- and StateMachine views are a very useful way to explore and understand HDL designs, but sometimes that just doesn’t cut it. The diagrams can be too complex and crowded to understand a design. For this reason, the diagrams can’t always be directly used in documentation. To solve this challenge you can make use of the Graphics Configuration Language.

The Language

The Graphics Configuration Language is a plain text file containing declarations and configurations, which when interpreted, result in grouping, filtering and coloring in the diagram. You can see it in action in the images below:

This BlockDiagram

Original BlockDiagram

Turns into:
Filtered BlockDiagram

This StateMachine

Original StateMachine

Turns into:
Filtered StateMachine

A plain text format was chosen over a buttons and menus for several reasons:

Getting started

To get started, choose a design with a BlockDiagram or StateMachine you want to simplify.

Create a new Graphics Configuration file by going to File > New > Other > Graphics Configuration > Graphics Configuration File. You can also press the Sigasi button on the top right of the BlockDiagram or StateMachine view.

From there, you can declare groups and configure your diagram, check it in to version control and share it with your colleagues. Auto-complete (Ctrl+Space) helps you write most of the code while formatting (Shift+Ctrl+F) helps you to keep your file clean. If you’re interested in the language’s exact syntax, you can find it here.


The Graphics Configuration features:

Note that in the BlockDiagram you can group blocks and wires while in the StateMachine you can only group states.

Graphics Configuration Editor features:

Graphics Configuration for BlockDiagrams

You can express which diagram you want to filter in the first line of the file by writing diagram fullyQualifiedName. The fully qualified name in VHDL is always library.entity.architecture. In SystemVerilog this is work.module.
E.g. if you want to filter the diagram for the architecture RTL implementing the entity ent in the work library, you use the following line as the first line: diagram work.VME64xCore_Top.RTL.

The file is read from bottom to top. You start with the above definition of the diagram, then within that you can hide reassignments, create groups and finally, create configurations for ports, blocks and edges.

Hiding reassignments

When using a lot of reassignments or when you’re indexing vectors, you can get a skyscraper effect in the generated block diagrams. By using reassignments hide you can draw through the assignment blocks making the diagram a lot simpler.



Hidden reassignments

Hidden reassignments

Multiple reassignments

Multiple reassignments

Hidden reassignments

Hidden reassignments


After hiding the reassignments you can define groups of edges or blocks. The syntax for a group is as follows:
def Type group ID (Identifiers)
Where Type is block or wire, ID is the new name of the group and Identifiers is a comma separated list of existing IDs (Graphics Configuration, VHDL or SystemVerilog) or a regex.

The syntax for a regex is regex"regex_pattern". This uses Java regexes, you can also find a cheat sheet here. You can also check what the regex matches by hovering over the query.

E.g. if you want to group block2 and block3 you can add either of the following lines:
group block middle regex"block[23]"
group block middle (block2, block3)





The same can be done for wires by using wire instead of block.
Ports can be grouped by grouping the wires attached to the ports into a bus.


The syntax for a configuration block is as follows:
Type Identifiers { ConfigurationItem* }
Where Type is block, wire or port.

The syntax for a ConfigurationItem is as follows:
hide | collapse | color GraphicsColor | reassignments hide
You can discover which colors are available here or through the autocomplete.

E.g. we can color a block, called middle, green and hide its internals:
Colored and collapsed group

Colored and collapsed group

Configurations are not cascading (unlike CSS). Coloring the middle block green does not turn all its internal blocks green as well.

Note that the language can not see everything: it can not see blocks, wires or ports that are within another block.
E.g. we can’t type block block3 { color red } as block3 is part of the block middle. To access a block within a block, we have to nest configurations.

Nested configuration

Nested configuration

Another use case would be to hide (unconnected) ports by using port a { hide }.

Hidden port

Hidden port

Note that when you hide a block or port, the edges that are connected to them will also be hidden.

It is also possible to hide reassignments in configurations, as you saw in the above skyscraper example, the reassignment in the generate block was not hidden. You can do so as follows:

Hidden reassignment in generate

Hidden reassignment in generate

Graphics Configuration for StateMachines

StateMachines are configured in the same way as the above BlockDiagrams, except the only Type that can be used is state. The header is also slightly different, the syntax is as follows:
statemachine architecture : state_variable.

For an example you can check out 4_state_machines.vhd (in our VHDL Tutorial) with this filter file.

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Third party plugins

Since Sigasi Studio is built on Eclipse, you can install third party Eclipse plugins.

The best place to start looking for a plugin is the Eclipse Marketplace. We list some interesting plugins here. Since these are third party plugins, there is no official support from Sigasi.

Installing plugins

Unlike most Eclipse distributions Sigasi Studio is shipped without the Eclipse Marketplace plugin, and without the standard Eclipse update sites. Hence, you have to use the old mechanism for installing new plugins, and add the plugin update site.

Revision Control Systems

Sigasi Studio supports a wide range of Revision Control Systems (also know as Version Control or Source Control systems). Support for revision control is based on Eclipse plugins. This section contains a preliminary listing of the most popular revision control systems.


Recommended plugin: EGit This plugin is shipped with the standalone version of Sigasi Studio.

Subversion (SVN)

There are 2 alternatives.


The Subversive plugin (Installation instructions) is only available up to Eclipse oxygen. As update site, you should use:


To install the Subclipse plugin, perform these steps in the Help > Install New Software… window:


Recommended plugin: ClearCase (Update site:

Note that this is the Open Source ClearCase plugin hosted on SourceForge, not the official ClearCase plugin distributed by IBM .

Learn more about ClearCase.

Local history

While this is not strictly speaking a version control system, Sigasi Studio has a built-in feature that keeps a local history of your files. Learn more.

Other systems

Some other popular revision control systems include:

  1. CVS learn more.
  2. Mercurial (Hg) learn more.
  3. Perforce learn more.

VI and Emacs

Other languages

Opening to a shell

If you want a quick way to open files and folders from the Project Explorer in a terminal, EasyShell is a useful plugin.

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The user interface is unresponsive

If the user interface of Sigasi Studio is unresponsive, you can interrupt the internal compilation process by pressing the stop button in the progress view. To activate the progress view, select Window > Show View > Other… > General > Progress, or click the tiny conveyor belt icon , on the right side of the status bar.

The editor displays old contents of a file

If you edit a file outside of Sigasi Studio with an external editor, Sigasi Studio will normally notice the changes and ask if you want to load the changes. If it doesn’t, you can refresh the editor’s content by pressing F5 or by right-clicking a file or a project in the project explorer and selecting Refresh.

How much local history will be stored?

Sigasi Studio stores the history of your file so that you can compare your current version with the version you saved an hour ago.

You can define how much disk space is used for storing local history in Windows > Preferences, select General > Workspace > Local History.

For more information on local history, check out this page.

I see hundreds or thousands of errors

If you see a large number of errors, you either have very, very buggy code (not so likely) or your project is not configured correctly.

  1. Check that all files are mapped to the correct library.
  2. Check that all stale files are ignored. (see the section on unneeded files)
  3. Check that all third party libraries are included.
  4. Make sure that automatic build is enabled.

Auto Build is not Enabled


Cause: Project is not built automatically

Resolution: Enable automatic project builds: Project > Build Automatically

Project does not have VHDL support


Cause: The project does not have VHDL support enabled

Resolution: Enable VHDL support: right-click the project > Configure > Add VHDL support

Project does not have Library Mapping Information


Cause: The project does not have a (valid) VHDL library mapping information file

Resolution: Reset the library mapping: right-click the project > Library Mapping > Reset Library Mapping

Project does not have Common Libraries


Cause: Common libraries are not configured correctly.

Resolution: Reset the common libraries: right-click the project > Library Mapping > Reset Library Mapping

Sigasi Studio analyzes HDL files that I do not need

By default, Sigasi Studio assumes that all VHDL or Verilog files are part of the project. However, some projects may contain multiple files with older or alternative definitions of a VHDL object. We call these stale files, because they are no longer used. In such a case you will want Sigasi Studio to ignore certain files.

To exclude files (or directories) from analysis, consult the Libraries manual page.

Ignored resources are decorated with a icon in the project explorer view.

Sigasi Studio startup fails: “Could not create the Java virtual machine”

On some computers, the standalone version of Sigasi Studio will fail to start with an error message similar to: “Could not create the Java virtual machine.” This happens especially on 32-bit Windows machines with less than 2GB of physical memory. The reason is that the Java virtual machine tries to allocate more memory than what is available.

In order to solve this, you can decrease the default heap size settings. You can do this by adding following lines to sigasi.ini or eclipse.ini in your Sigasi Studio installation folder:


This sets the maximum heap size to 1000 MB (instead of the standard 3GB).

Note: Do not use eclipsec.exe, as this will ignore all of the settings configured in the eclipse.ini file.

Sigasi Studio shows a startup message about port 4444 already being in use

If you want to run Sigasi Studio on a server with multiple users, the configuration files should be updated according to the descriptions here.

I want a clean restart

If you ever suspect that the state of your project is inconsistent in Sigasi Studio, you can do one or all of the following things. Consider these steps to be advanced usage; you should not need them during normal operation.

Force a clean compilation

You can force a completely clean compilation by selecting: Project > Clean … > Clean All Projects > OK.

Remove stale markers

Sometimes markers remain visible, even after the problem is fixed or when a file is excluded from compilation. We call these stale markers and they are can be caused by a crash during compilation.

You can delete these stale markers from the Problems View: In the Problems View, select the markers and press DEL (or right-click and select Delete).

Note that during the next build, the tool may generate new markers. If you want to suppress certain warnings, you can configure the linting rules.

Remove the workspace state

Much of your configuration and cached data is stored in your workspace. By default, Sigasi Studio’s workspace is located in ${HOME}/workspaceSigasi. A lot of this data is stored in the hidden .metadata directory. Sometimes, a part of your metadata can become corrupt. It can help to remove the .metadata directory (take a backup first!). This clears all of your workspace state.

Keep getting reports about an “Incompatible version of Quartus II”

If you are using the integration with Altera Quartus II. Some people keep getting a dialog box that says:

Incompatible version of Quartus II

Project interface was created with an older, incompatible version of Quartus II. Is it OK to upgrade the project to match the installed version of Quartus II?

Obviously, you should upgrade the project. If this message keeps popping up, you may want to check that Sigasi Studio is using the correct version of Quartus II, in the Sigasi Studio application: Window > Preferences > Sigasi > Toolchains > Altera Quartus II.

Contact support

If this troubleshooting guide did not solve your problem, please send us an email .

Any of the following information will help us help you:

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Keyboard Shortcuts

As you become more experienced with Sigasi Studio, you will find that there are a number of actions that you perform quite often. At some point, you may feel that the GUI-based approach becomes too slow for these actions. For that reason, Sigasi Studio provides a number of keyboard shortcuts. They are a great way to boost your productivity. A printable cheat sheet with all shortcuts on one page is available for download.

A printable cheat sheet with all shortcuts

In this chapter, we describe the available keyboard shortcuts.

Top keyboard shortcuts

In this section, we list the most important shortcuts.

  1. Open Resource (Shift+Ctrl+R):
    Shift+Ctrl+R opens a dialog that allows you to swiftly open an editor on any file in the workspace.
  2. Open Declaration (F3):
    Use F3 to navigate to the declaration of the selected identifier.
  3. Open Design Unit (Shift+Ctrl+D):
    Shift+Ctrl+D opens a dialog in which you can type a name or pattern to open a specific VHDL or SystemVerilog design unit name.
  4. Backward History (Alt+Left):
    Often, when you navigate to a declaration you want to go back to where you came from; just press Alt+Left.
  5. Content Assist (Ctrl+Space):
    With content assist (autocomplete) you can really speed up coding VHDL. Just press Ctrl+Space to get a suggestion of possible autocompletes in the current context.
  6. Go to next marker (Ctrl+.)
    Does your file contain warnings or errors? Quickly navigate to the next problem by pressing Ctrl+. (Ctrl+, jumps to the previous problem).
  7. Quick Fix (Ctrl+1):
    To fix problems even quicker, navigate to the problem with the previous shortcut. Press Ctrl+1 to activate the Quick Fix, select the fix with the UP or DOWN keys and execute the Quick Fix with Enter.
  8. Go to Line (Ctrl+L)
    You can directly jump to a certain line with this shortcut. You can display the line numbers by right-clicking on on the gray bar on the left side of the editor view and clicking on Show Line Numbers.
  9. Search references (Shift+Ctrl+G)
    To search for all occurrences of a given identifier, just select the identifier and press Shift+Ctrl+G. The search view is displayed, with a match for each occurrence (possibly in multiple files)
  10. Rename Refactoring (Shift+Alt+R)
    Once you get used to the rename refactoring you will be using it all the time. Use Shift+Alt+R to run it even quicker.
  11. Toggle Block Selection (Shift+Alt+A)
    Switch between regular and block selection mode.
  12. Structured Select (Shift+Alt+Up/Down/Left/Right)
    Select VHDL or Verilog code, based on its syntactic structure. (Structured selection)
  13. Format (Shift+Ctrl+F)
    Format your current VHDL or SystemVerilog file.
  14. Quick Access (Ctrl+3, This is the shortcut to use, when you forgot the shortcut you actually need.)
    With Quick Access you can quickly find open editors, available perspectives, views, preferences, wizards, commands, etc. Simply start typing the name of the item you wish to invoke.

Keyboard shortcut reference

CategoryDescriptionKeyboard shortcut
Basic EditingDeleteDelete
CopyCtrl+C, Ctrl+Insert
PasteCtrl+V, Shift+Insert
CutCtrl+X, Shift+Delete
Select AllCtrl+A
Toggle Block SelectionShift+Alt+A
Toggle Word WrapShift+Alt+Y
Zoom inCtrl++
Zoom outCtrl+-
Quick FixesQuick FixCtrl+1
AutocompletionContent AssistCtrl+Space
Word completionAlt+/
Basic SearchFind and ReplaceCtrl+F
Find NextCtrl+K
Find PreviousShift+Ctrl+K
Incremental FindCtrl+J
Incremental Find ReverseShift+Ctrl+J
Close AllShift+Ctrl+F4, Shift+Ctrl+W
CloseCtrl+F4, Ctrl+W
New menuShift+Alt+N
Save AllShift+Ctrl+S
NavigationLast Edit LocationCtrl+Q
Open ResourceShift+Ctrl+R
Open Design UnitShift+Ctrl+D
Backward HistoryAlt+Left
Show In…Shift+Alt+W
Go to LineCtrl+L
Go to Matching BracketCtrl+Shift+P
Collapse AllShift+Ctrl+Numpad_Divide
Forward HistoryAlt+Right
VHDL/Verilog specificSearch referencesShift+Ctrl+G
Rename - RefactoringShift+Alt+R
Toggle CommentCtrl+/
Open DeclarationF3
Open matching entityShift+F3
Go to next problemCtrl+.
Go to previous problemCtrl+,
Expand structured selectionShift+Alt+Up
Contact structured selectionShift+Alt+Down
Expand structured selection leftShift+Alt+Left
Expand structured selection rightShift+Alt+Right
Advanced searchFind Text in WorkspaceCtrl+Alt+G
Open Search DialogCtrl+H
Previous WordCtrl+Left
Advanced editingInsert Line Above Current LineShift+Ctrl+Enter
Scroll Line DownCtrl+Down
Delete Next WordCtrl+Delete
Test StartCtrl+Home
Toggle OverwriteInsert
Insert Line Below Current LineShift+Enter
Delete Previous WordCtrl+Backspace
Delete LineCtrl+D
Copy LinesCtrl+Alt+Down
Duplicate LinesCtrl+Alt+Up
Move Lines DownAlt+Down
Delete to End of LineShift+Ctrl+Delete
Select Next WordShift+Ctrl+Right
Scroll Line UpCtrl+Up
Select Line EndShift+End
Move Lines UpAlt+Up
Join LinesCtrl+Alt+J
To Upper CaseShift+Ctrl+X
Select Line StartShift+Home
To Lower CaseShift+Ctrl+Y
Select Previous WordShift+Ctrl+Left
Next WordCtrl+Right
Text EndCtrl+End
Line StartHome
Line EndEnd
Show Tool TipF2
ViewsMaximize Active View or EditorCtrl+M
Next EditorCtrl+F6
Next ViewCtrl+F7
Show View MenuCtrl+F10
Show Key AssistShift+Ctrl+L
Show System MenuAlt+-
Show Ruler Context MenuCtrl+F10
Previous EditorShift+Ctrl+F6
Activate EditorF12
Switch to EditorShift+Ctrl+E
Previous ViewShift+Ctrl+F7
Quick AccessCtrl+3
Quick Switch EditorCtrl+E
Toggle Full screenAlt+F11
Toggle Horizontal Split EditorCtrl+_
Toggle Vertical Split EditorCtrl+{

Mac users

If you are using Mac OS X, most of these keyboard shortcuts use Command instead of Ctrl. To inspect the exact list of keyboard shortcuts, go to Preferences > General > Keys.

Customizing keyboard shortcuts

Keyboard shortcuts can be easily customized via Preferences > General > Keys.

This preference page also enables you to select the Emacs scheme, for more Emacs-like keyboard shortcuts, or (if you have installed the UltraEdit key bindings for Eclipse plugin) the UltraEdit key bindings.

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Configuring Your Design Environment

Choosing your VHDL and Verilog version

Sigasi Studio supports VHDL version 1993, 2002 and 2008 and Verilog (2005) and SystemVerilog (2012). You can select the default VHDL version to use in: Window > Preferences > Sigasi > VHDL. You can set the default Verilog version in: Window > Preferences > Sigasi > (System)Verilog.

Since Sigasi Studio 3.2, you can also set the language version per project, per folder and per file. In the Project Explorer, right click your project, folder or file; select Properties > VHDL Version or Properties > (System)Verilog Version and select the version via the dropdown menu.

When you change the language version of a file, only that file is affected. However, when you change the version of a folder, then everything in that folder will have the new language version. Any overrides in the folder and its sub-folders will be removed. When you are defining the language versions for a new project you should map from top (project root) to bottom (files).

The version information is stored in <project path>/.settings/com.sigasi.hdt.vhdl.version.prefs and <project path>/.settings/com.sigasi.hdt.verilog.version.prefs. We recommend you add this file to version control so you can share it with your team.


Colors and Fonts

You can configure the code coloring by selecting Window > Preferences > Sigasi > VHDL > Syntax Coloring. For each class of semantic and syntactic elements, you can select the font, letter color, background color, style (bold, italic, underline, strike through).

Font size

Sometimes you want extra small fonts, so that you can fit more content on your screen. Another time you may want extra large fonts, so that you can use a beamer and your audience can see what you are doing.

Most fonts, including the font that is used by the editors, can be controlled in the preferences: Window > Preferences. Fonts are controlled in General > Appearance >Colors and Fonts. The font of the editors are in Basic > Text font.

Some fonts cannot be controlled in this preference page. These fonts are defined by general system settings, and are used for writing the menu names, the Project Explorer view and the Outline and Hierarchy views. On Windows, you can change these fonts by changing your font settings in the Windows Control Panel. On Linux, these fonts are controlled by a settings file: ${HOME}/.gtkrc-2.0 . You can change the font by adding a line like:

gtk-font-name = "Sans 10"

You have to restart Sigasi Studio before these changes take effect.

Annotations Colors

Annotations are colors added on top of your text editor, and to the right of your text editor, in the scroll bar. The image below shows annotations for each occurrence of a certain data type. The color has been changed to bright green.

Annotations in Bright Green

You can change the color of annotations in Window > Preferences > General > Editors > Text Editors > Annotations. For the particular case of occurrence annotations, you want to modify the color for annotation type Occurrences. If more than one Occurrences type is displayed, you need the org.eclipse.xtext.ui.editor.defaultOccurrenceAnnotation. The others may refer to occurrences for Java or other plug-ins.

Tabs and Spaces

If you want to use spaces instead of tabs, you can set your indentation preferences in: Window > Preferences > General > Editors > Text Editors. Here you can select choose to Insert Spaces for Tabs and choose your preferred Displayed Tab Width.

The “Gutter”

The Gutter is the small area to the left of the editor view. It is used for displaying extra information about your code.

There is not much to configure about markers, but the other categories can be turned on or off.

Line numbers

To enable line numbers, right-click in the gutter and select Show Line Numbers.

Quick Diff

Instead of using a compare editor, you can enable quick diff support and see the changes within the text editor. This feature can be enabled via Window > Preferences > General > Editors > Text Editors > Quick Diff.

When you enable Quick Diff, you can see changes in the active editor with the version on disk (or the latest version in version control), by hovering the annotations in the gutter.

more info

Linting rules

You can choose the severity of linting rules in: Window > Preferences > Sigasi > VHDL > Errors/Warnings. Read more information about Linting and Quick Fixes.


Eclipse is available in several languages, and you can install the language pack of your choice. Read more in this support article : Installing translations for Eclipse

Keyboard shortcuts

Sigasi Studio comes with a large number of Keyboard Shortcuts preconfigured. You can configure keyboard shortcuts (key bindings) in Window > Preferences > General > Keys. You can modify individual keyboard shortcuts or add new key bindings. There is also a preconfigured scheme for Emacs-like keyboard shortcuts.

After you have configured your keyboard shortcuts, you can export your settings and share them with your colleagues (or re-import them on another computer): To export, go to File > Export… > General > Preferences, and select Key Preferences. To import that file: File > Import… > General > Preferences.


Formatting options for VHDL are documented in the VHDL Code Formatting section of the Editor manual.

Finding more options

[Not Documented Yet]
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License Key Management


Sigasi Studio’s license key management system is based on the well known FlexNet (a.k.a. FlexLM) license manager. Sigasi Studio supports both node-locked and floating license keys. The Sigasi Studio edition is controlled by the license key.

Node locked licenses

If you have a node-locked license, you can enter your license key directly in Sigasi Studio.

  1. Open the Sigasi Studio License Key preference page: Window > Preferences > Sigasi > License Key
  2. Click Edit License File
  3. paste your key in the dialog

An example node-locked license looks like this. Note that the first line starts with INCREMENT

INCREMENT com.sigasi.hdt sigasi 2.0 18-nov-2012 uncounted \
        VENDOR_STRING=";mac:10f2dd92c5ac;name:John \
        Doe;type:trial" HOSTID=ANY ISSUER=Sigasi ISSUED=21-Oct-2012 \
        START=21-Oct-2012 SIGN="0CCC 87EA 9BB6 256E 7D81 E49D B2A6 \
        E53D 1CA5 41D4 63DF 8671 5695 EF82 0E30 1028 732D DED3 0999 \
        FD11 8B97 42B0 7CF2 F51F 20A0 DA6E 7F54 9D64 FF29 49AB"

Floating licenses

If you have a floating license key, you need to configure both a license server and Sigasi Studio.

An example floating license looks like this. Note that the first line starts with SERVER or DAEMON:

DAEMON sigasi port=27001
SERVER your_server_name1 BD41FCF5DE27 27000
INCREMENT com.sigasi.hdt sigasi 2.0 18-nov-2012 4 \
        VENDOR_STRING=";mac:10f2dd92c5ac;name:John \
        Doe;type:trial" HOSTID=ANY ISSUER=Sigasi ISSUED=21-Oct-2012 \
        START=21-Oct-2012 SIGN="0960 9728 7193 4DA5 15C2 3652 21E1 \
        EF82 1060 8FC1 9EA6 0C43 4842 C50B 684F E4DA 8EEF 37E9 5384 \
        8DF4 106C 52B4 EECE 0A69 CBAC 0CF2 47E2 00F2 A244 E22F"

Configuring Floating license in Sigasi Studio (FlexNet Client)

In order to use a floating license, Sigasi Studio needs to know how to contact the server. The license server can be configured in Sigasi Studio or using an environment variable.

Configure the license server in Sigasi Studio

In Sigasi Studio, navigate to the License Key preference page via: Window > Preferences > Sigasi > License Key. Next enter <portnumber>@<servername> in the License key path. For example:

If you have redundant license servers, enter each of the license servers separated by “&“. For example:

If you leave the License key path empty, Sigasi Studio will try to use an environment variable to find the license server.

Configure the license server in an environment variable

You can also set your license server via an environment variable instead of configuring it in Sigasi Studio. Both SIGASI_LM_LICENSE_FILE and LM_LICENSE_FILE are supported. When SIGASI_LM_LICENSE_FILE is set, LM_LICENSE_FILE is ignored.

Note that if you want to use an environment variable, you can not enter a path in the License Key preference page. The value on this page has priority over environment variables.

Linux Example:


For redundant license servers, the servers should be separated using “:” on Linux and using “;” on Windows.

Linux Example:


License server setup

Download the FlexNet daemons

FlexNet version

FlexNet version

Customize License Server settings

You can change the port of the FlexNet and Sigasi daemon by changing the port numbers in the license key. By default ports 27000 and 27001 are used.

The port of the Sigasi daemon is set on the DAEMON line. For example: DAEMON sigasi port=27001, forces the Sigasi daemon to use port 27001.

The port of the FlexNet daemon is set on the SERVER line For example: SERVER your_server_name1 BD41FCF5DE27 27000, forces FlexNet to use port 27000.

You can change the ports and servername without breaking the signature.

Starting the FlexNet and Sigasi daemon on Linux

the easiest way to start the Sigasi FlexNet daemon is like this (on Linux)

echo "Starting the Sigasi floating license server"
$LOCATION/lmgrd -c $LOCATION/sigasi.lic -l $LOCATION/debug.log

Starting the FlexNet and Sigasi daemon on Windows

  1. Download the Sigasi daemon (see above)
  2. Create a folder to hold the license manager software, in this example we will use D:\Sigasi\license.
  3. Unpack the zip file into the license folder (D:\Sigasi\license)
  4. Run the license configuration tool lmtools.exe as administrator.
  5. Save the license file supplied for Sigasi Studio to the license folder
  6. Using a text editor, edit the license file and replace your_server_name1 with the name of the machine you are using, for example: From: SERVER your_server_name1 74e50bb0911e To: SERVER Maple 74e50bb0911e

    Note: If you are not sure of the name of the machine you are using click on the System Settings tab of lmtools, where it is shown, see below:

  7. Click on the Config Services tab and fill in the following, use the browse button when available:

    • Service Name: Sigasi License Manager
    • Path to lmgrd.exe: D:\sigasi\license\lmgrd.exe
    • Path to license file: D:\sigasi\license\sigasi.lic
    • Path to the debug log file: D:\sigasi\license\debug.log Note: You will probably need to type the “Path to the debug log file”, in full as the file will not exist so you cannot browse to it.
  8. Ensure both the following check boxes are checked:

    • Use Services
    • Start Server at Power Up
  9. Now click the Save Service button, and click yes on the confirmation dialog.

  10. Switch to the Start/Stop/Reread tab and start the server.

The license server should now be configured correctly, and looks a bit like this one

Floating License options

Release a floating license

You can release a floating license (check a license in) without closing your Sigasi Studio application or Eclipse application. This is useful if you use Eclipse to edit other files than VHDL files, like C or Tcl.

First, make sure that all VHDL and Verilog files are closed and all VHDL and Verilog projects are closed. Next select Help > Sigasi > Floating license > Release Sigasi Floating Licenses

To get the license back (to check the license out), open the license dialog Help > Sigasi > Configure License… and press Apply.

How to block Sigasi Studio from checking out a license?

If you have configured an environment variable with the location of a FlexNet license server, you can instruct Sigasi Studio not to check out a license by setting the Sigasi Studio License key to none.

Mix of Creator and XL licenses

If your license server serves both Sigasi Studio Creator and XL licenses, you can configure Sigasi Studio to only checkout Sigasi Studio Creator licenses (and not XL licenses) by enabling the “Do not try to checkout floating Sigasi Studio XL licenses” option on Window > Preferences > Sigasi > License Key > Floating Options

Checking out and releasing the XPRT license

If you have licenses for Sigasi Studio XPRT, this is actually licensed as a Sigasi Studio XL Flexnet feature and an XPRT Flexnet feature. The XL license is checked out as described above.

The XPRT license is checked out automatically in the following cases:

The XPRT license is released via: Help > Sigasi > Floating license > Release Sigasi Studio XPRT Floating Licenses.


If your license key does not work, the first things to check are:

Floating licenses

If your floating license server does not function properly, try the following steps:

If the steps above do not help, feel free to send us an email and send us a screenshot of the license dialog with the error message.

Typical error messages

Check the content of the Sigasi License preference page via : Window > Preferences and Sigasi > License Key

No license

No Such Feature Exists

Invalid license key (inconsistent authentication code)

Internal Flexlm Error

Invalid Message Received From License Server

Updating DACL Failed: “Service has been created but failed to update the DACL settings of FlexNet Licensing Service. It will give problem for accessing TS features. Check whether FlexNet Licensing Service is correctly installed or not and delete and create this service again.”

(lmgrd) license manager: can’t initialize:No SERVER lines in license file.
(lmgrd) License Path: “C:\FlexLM\sigasi\license.dat”
(lmgrd) FlexNet Licensing error:-13,66

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Sigasi Studio Talkback

Talkback is a Sigasi Studio service that automatically collects metadata about how Sigasi Studio is used and sends this metadata to Sigasi through a secured connection.

Why should I enable Talkback?

By enabling Talkback you help us improve Sigasi Studio:

The end result is that you can use an always-improving Sigasi Studio.

How does Sigasi use this information

Sigasi uses the information transmitted by Talkback for marketing and product planning and development. We use it for deciding which features to develop and improve, for finding and fixing bugs and for finding and fixing performance issues.

What kind of information is sent through Talkback?

Talkback transmits meta-information about your project, operating system, Java Virtual Machine, tool usage, and incident reports (stack traces) that occur due to software errors. Talkback never transmits any HDL code. All transmissions are through an industry standard SSL secure connection, unless you choose to use plain text transmissions.

In the Talkback transmissions, we identify your Sigasi/Eclipse workspace using a generated identifier (a standard Java universal unique identifier UUID).

Talkback stores all the information it transmits in a log file, so that you can inspect it. The information is human-readable, in JSON (JavaScript Object Notation) format.

You can access the Talkback log to verify by clicking Window > Preferences > Sigasi > Talkback > Talkback log.

This log file is rotated for each new Sigasi Studio session or when the log reaches a certain size.

How do I enable or disable Talkback?

Talkback is always disabled by default. To enable Talkback, or to disable it later on, click Window > Preferences > Sigasi > Talkback and select or deselect the checkbox “Enable Talkback”.

What about my Firewall or Proxy?

By default Talkback uses the https protocol to send the information. If your firewall blocks SSL connections you can use the http protocol: go to Window > Preferences > Sigasi > Talkback and select the checkbox “Send unencrypted”. Your firewall should allow outgoing connections to port 443 for https or port 80 for http.

Talkback does not support Proxies. If Talkback is unable to connect to our server directly because of your firewall or proxy server, you need to purchase a commercial license.

Features like Talkback are against our corporate policy, even if it is disabled. What can I do?

Please send us an email so that we can discuss a solution for your company.

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This single page manual was generated on 2020-01-22.