VCD Files

Any currently viewed channel data or bus data can be exported into an IEEE standard VCD (Value Change Dump) file. The VCD file format is an ASCII text file format for waveform information, which can be imported by many popular logic simulators, logic analyzers, and waveform viewers. Signals from VCD files can also be imported back into the ChronoVu software, providing an easy method for comparing the results from two or more different acquisitions or comparing simulated results to acquired results. When ChronoVu data is exported to a VCD file, the exported data will be written according to all currently defined signal names and bus definitions. Only visible signals or bus channels will be included in the exported file.

Preparing to Export Waveform Data

Before exporting the VCD file, insure that all signal names and buses that are to be included in the output are appropriately defined and visible (see Bus Analysis Setup for assistance).   All visible signal and bus names will be written directly into the VCD file, so it is important to insure that signal names are appropriate for importation into the program of choice.  It is usually advisable to avoid white spaces and other special characters in the signal names. Once the signals and bus parameters are set, pan and zoom the visible window until the edges of the visible window roughly define the portion of the waveform that is to be written into the VCD file.

Exporting the Data

To export the data into a VCD file, click on the File–>Export Data in VCD format menu item from the menu bar. (see User Interface for assistance).  Select the sample window to be exported on the VCD Export pop-up window using the spin buttons provided. Initial values will be pre entered as defined by the currently visible window, however these values can be adjusted as needed.  Time t=0 in the VCD output file will be defined as the left edge of the exported window.  Once the desired window has been set, simply click OK.  A file name will be requested, after which the exported file will be generated.