Simulation integrates with measurement to advance high-speed design

Integration of simulation and measurement was a key topic at DesignCon last week. As previously reported, Tektronix president Pat Byrne delivered a keynote address on the topic. Keysight Technologies highlighted its extensive product line extending from simulation software to oscilloscopes. And Computer Simulation Technology (CST) and Wild River Technology (WRT) presented initial results of their cooperative effort to demonstrate the correlation of simulation and measurement for high-speed digital designs.

The CST and WRT demonstration focused on 3D electromagnetic field simulation, which, the companies said, is increasingly important as DDR4, SerDes, and other devices operate at ever higher speeds.

The demonstration was based on CST STUDIO SUITE software whose simulations can be verified against measurements made using WRT’s CMP-28 channel modeling platform, which includes a range of structures for benchmarking 3D EM simulations and verifying simulation and measurement methods.

“A strong correlation between measurement and simulation is absolutely critical to the successful use of the simulation tools,” said Dr. Klaus Krohne, market development manager for EDA at CST in a press release. “This cooperation with Wild River Technology means that users can now simulate the behavior of a high-speed channel and then easily check the simulated results against real measured data. This will not only give users more confidence in their results but also help them to avoid some of the common measurement or simulation mistakes that can slow down the development process.”

Keysight Technologies has addressed simulation and measurement links at least as far back as 2003 (when it was then the electronic measurement business of Agilent Technologies), leading to its current lineup of design and test integration technologies for industries ranging from wireless communications to aerospace and defense.

At DesignCon, Brad Doerr, senior R&D manager for the company’s Oscilloscope and Protocol Division, cited Keysight offerings that embrace design and simulation, analysis and debug, and compliance.

In addition to highlighting such products on the DesignCon exhibit floor, Keysight authors along with coauthors from TE Connectivity and the University of Ghent presented a paper titled “PAM-4 Simulation to Measurement Validation with Commercially Available Software and Hardware” (password required for access).

On the simulation side, the authors employed the Keysight Advanced Design System (ADS) software package that uses the IBIS-AMI methodology to simulate a PAM-4 link over a QSFP28 cable assembly. On the measurement side, they used instruments including the Keysight M8195A arbitrary waveform generator (to replicate the simulated Tx stimulus generated by the ADS IBIS-AMI model) and an 86108B precision waveform analyzer.

The authors concluded, “The ability to simulate the FFE corrected waveform on the simulation side and then use this exact waveform generated by an AWG on the measurement side resulted in excellent measurement to simulation correlation for a PAM-4 SERDES channel.”

Tektronix’s Byrne in his keynote address last week emphasized the importance of measurement science from the probe tip to the pixel on the instrument screen. But he also addressed the importance of software, saying that taking the industry to the next level will require the integration of simulation and measurement technology.

Tektronix’s specific product aimed at such integration is TekScope Anywhere software. Introduced at DesignCon 2015, TekScope Anywhere decouples analysis tools from the oscilloscope, facilitating collaboration with colleagues around the world.

TekScope Anywhere also supports analysis in simulation prior to the arrival of silicon. For these scenarios, TekScope Anywhere enables measurements on simulation data using the same algorithms that the oscilloscope will use during silicon PHY characterization post-fabrication. TekScope Anywhere supports a variety of waveform formats from oscilloscopes or simulation environments, including .h5, .wfm, .csv, .bin, .trc, and .tr0.

“TekScope Anywhere enables our oscilloscope customers to collaborate and work in a more flexible environment,” said Brian Reich, general manager, Performance Oscilloscopes, Tektronix, at the time of the product’s introduction. “For example, customers can now solve measurement correlation issues across multiple waveform formats from a variety of scopes and simulation environments—independent of the scope hardware.”