CST IBIS Viewer

IBIS is short for I/O Buffer Information Specification. It is an ASCII data format standard used by many IC vendors and a valuable tool for easy and successful Signal Integrity analyses (see SITD). The CST IBIS Viewer can be used to get a quick overview on the IBIS models which are used in CST PCB STUDIO or CST DESIGN STUDIO. Also simple changes of the model can be done with the CST IBIS Viewer. The IBIS viewer can be reached via IBIS_viewer of the I/O-modeling (see I/O Device Modeling) or by changing to the schematic View ribbon via View:Change View/ToolsIBIS Viewer.

Main GUI

The GUI consists of a menu bar, a tree view with a property page, a graphical frame to display the waveforms and a transcript.

Tree View

In the tree view you can see all parts of the IBIS model which are relevant for the simulation.

Header Information: When selecting this item generic information about the IBIS model is shown in the property frame below.

Components: An IBIS model may contain one or more components. Each component contains a pin list. In case of active pins the model information is shown as well.

Models: Here you get a list of all models available in the currently opened IBIS file. Depending on the type a model contains ramp information, static curves (Pullup, Pulldown, POWER_clamp and GND_clamp) and dynamic curves (one or more rising waveforms and one or more falling waveforms). When selecting an item its properties are shown below and the corresponding curves are displayed in the graphical frame.

Model Selector: In some cases an IBIS file may use model selectors. Every selector contains a list of models. Instead of referencing directly to a specified model a pin can also refer to a model selector. In CST IBIS viewer only the first model of the selector will be used for the simulation.

Property page

Below the tree you can see the property frame. When selecting any item in the tree that contains any additional properties, you will see them here.

Graphical frame

By default a model view is shown in this field. In addition, separate charts and a text editor can be displayed.

Model View: When a model or a pin containing a model is selected in the tree the static or dynamic curves are displayed. With the buttons Static/Dynamic on the bottom left side you can switch between the two variants.

Separate Charts: When double-clicking on one of the small charts off the model view you can open a separate chart of the selected curve. Here you have the possibility to zoom in and out and to pick points via the context menu.

Text Editor: In the main menu you can open a text editor of the IBIS file. The keywords are shown in different colors for a better overview. Only large IBIS files will be displayed in monochrome due to performance reasons. When selecting any item in the tree view the editor will jump to the corresponding position in the IBIS file.

Transcript

The transcript informs you about the current workflow. When starting the standard IBIS file checker the results are listed there. When double clicking to an error or warning of the output the text editor will show the actual position in the IBIS file.

Menu bar

All important items of the menu bar can be reached directly about the icon tool bar.

File

• Open: Opens any other IBIS file. Only one IBIS file can be handled at the same time

• Close: Closes the currently opened IBIS file

• Save: Saves all changes you have made in the text editor. Disabled to prevent modification of currently used IBS files

• Save As: Saves the file with a new name

• Print: Prints the currently selected graphical or the IBIS file

• Exit: Exits the CST IBIS Viewer

Edit

• Cut: Cuts a marked section in the text editor

• Copy: Copies a marked section in the text editor

• Paste: Pastes a section which was copied first

• Find: Searches for any text string inside the text editor

View

• Colors: Changes the colors of curves displayed in the IBIS charts

• Line Width: Changes the line width of curves displayed in the IBIS charts

• Font Size: Changes the font size of the axes and legend displayed in the IBIS charts

• Inverse: Switches between black and white background in the IBIS charts

• Grid:  Switches on and off the grid inside the separate IBIS charts

• Legend: Switches on and off the legend in the IBIS charts

• Display Mode: All shows the typical, minimum and maximum curves of an IBIS file at once. The three curves can be displayed separately, too.

• Sort Pins/Models: The pin list in the tree can be sorted by the pin id or by the signal name.

Modeling

• IBIS File Check: Starts the golden IBIS parser to check the syntax and the correctness of the IBIS file. The results are shown in the transcript. When double clicking on an error or warning containing a line number the IBIS text editor will jump to this position.

Window

• IBIS Curves: Shows the window containing the passive or active curves off the currently selected model or pin. To switch between the passive curves (Pullup, Pulldown, POWER_clamp and GND_clamp) and the active curves (falling and rising waveforms) use the buttons below the tree view.

• IBIS File Editor: Opens a text editor with the IBIS file. Simple editing functions can be done inside this editor. Selecting any items in the tree view will force the text editor to jump at the actual position.

• Separate Charts: For Pullup, Pulldown, Power Clamp, GND Clamp, Falling and Rising Waveform a separate chart can be opened. This chart will show the curve of the currently selected model.

Help

• Help Contents: Opens the CST online help.

• About: Shows the version of the CST STUDIO SUITE