(Viewer) 3: Creating a Filter File to selectively load signals

The Set Filter File feature allows you to specify an optional "filter file" that controls what signals get imported from a waveform file (e.g. a VCD file) and the order in which they get imported. This feature is particularly useful when you need to repeatedly view the same subset of signals in several waveform files. The signal properties, such as MSB, LSB, and direction, are also controlled by the signal information that is stored in the filter file. Filter files do not contain any waveform data. Below we will change the ordering of the signals we imported in step 2 and save them into a filter file.

Drag ABUS to the top of the signal list:

•Drag and drop the ABUS signal label up to the top of the signal list so that the signals are no longer in the default order.

move_abus_start

move_abus_end

Save the Diagram as a Waveform Filter file:

•Select the File > Save As menu option to open the Save As dialog.

•In the Save As type drop-down, select Waveform filter (*.tim) if it is not already selected.

•Type VCD_Filter as the name of the filter file in the File name edit box.

filter_save

•Click the Save button to create the filter file.

Setup the viewer to use the filter file:

Once a filter file is created, it needs to be set as the current filter file to enable it. Once a filter file is set, each subsequent waveform file load will only load signals that match the filter file signal names.

•Select the Import/Export > Set Filter Diagram file for Import menu option to open the Filter Diagram File dialog.

•Check the Use Filter checkbox.

•Select the file by clicking the Browse button and finding where you saved it in the previous section.

•Click OK to close the dialog.

Set filter file

Test the Filter file by loading the original BTIM file:

When a filter file is set, only the filtered signals will be loaded. The filter file will operate on all files that are loaded, regardless of the file format. To try this out, let’s load the original BTIM file with the filter enabled:

•Open the exampleTim.btim file using the File > Open timing diagram menu.

•Notice that only the three buses that were in the filter file have been loaded. And notice that the signals are in the same order as listed in the filter file.

filter_load_file

•Also notice that the waveform's filename has been changed to FileName_FilterName.BTIM, so that you will not accidentally save this over the original waveform file.

Disabling the Filter file feature:

The filter file affects all files that are loaded, so you may need to turn it off when looking at a new file.

•Select the Import/Export > Set Filter Diagram file for Import menu option to open the Filter Diagram File dialog.

•Uncheck the Use Filter box.

remove filter file

•Close the currently open timing diagram, then choose the File > Open Timing Diagram menu and reload the exampleTim.btim file again. Note that all signals are now loaded from the diagram because we’ve disabled the filter file.