Analyzing Data Differently

What’s better than a waveform analysis? How about a data plot?


Data analysis is often a very time consuming process for a hardware design or verification engineer. We always end up using the waveform viewer which may not be very efficient in giving us a high-level overview of what we’re looking for. Data that is spread across a long simulation cycle is very hard to visualize on the waveform. Whenever I have to analyze a huge chunk of data, I always wonder what would be the best way to do it. It is often cumbersome to go through even a millisecond’s worth of waveform data to analyze the bigger picture. There are, of course, other tools that can take a VCD file and perform an analysis. But that involves buying and learning to use an additional tool.

Sometimes it’s not feasible to invest time and money into new tools. So we always go back to our trusty waveform viewer to make sense of the results. But what if there is a better way of analyzing such data, especially if you are doing some kind of signal processing application and have a lot of data that you would rather view in a format other than the time domain based representation of a waveform? For example, imagine you are trying to visualize the data of an FFT engine. On a waveform, it is next to impossible to visualize this.

The easier solution is to plot data using a plot viewer. Based on the settings, it will generate a plot of an object. It sounds very simple but it gives you a bigger picture of what your design object is doing over the course of the entire simulation, rather than just the slice you can see on the waveform between two points of time.

If the built-in plots feature does not provide you with all the details you are looking for, you can always consider exporting design objects to Matlab and creating your custom plots in Matlab. You can learn more about it here.

Aldec’s approach was to add a new plot window in the 2017.10 version of Riviera-PRO. It can now display a histogram, which gives you an accurate graphical representation of the distribution of numerical data. This type of representation not only gives you a higher level view of the design object but it also provides you with an indication of how the value is distributed over the course of the simulation. Coupled with our other plots – like the simple, polar and vector plots – along with the Image viewer, this provides a very efficient and powerful analysis.

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