Coherency verification, especially on a large System-on-Chip (SoC) with many masters, multiple load/store variants, and coherent components is a particularly complex operation. Typical verification techniques for generating tests and measuring coverage do not apply to these scenarios, which require different thinking. Algorithms that stress test the full SoC with a broad range of data access mechanisms are required that are designed to trip up the coherency protocols.

Coverage metrics must be measured at the scenario level, as any kind of implementation coverage metric is meaningless for coherency. This presentation will outline coherency verification methods that may be deployed across complex SoCs, an approach to automate their application, and methods to measure appropriate coverage. Its application on Arm and RISC-V systems, including custom instructions, will be described.

Key Points:

• Coherency verification is a unique process that render traditional techniques relatively ineffective.
• Automating coherency verification on complex SoCs require a range of specialized algorithms and coverage approaches.
• New RISC-V processors add further complexities over Arm and X86 systems.

Dave Kelf, is the CEO of Breker Verification Systems, the leader in test content synthesis using the PSS standard. Dave most recently served as vice president of worldwide marketing solutions at formal verification provider OneSpin Solutions. Earlier, Kelf was president and CEO of Sigmatix, Inc. He worked in sales and marketing at Cadence Design Systems, and was responsible for the Verilog and VHDL verification product lines. As vice president of marketing at Co-Design Automation and then Synopsys, Kelf oversaw the successful introduction and growth of the SystemVerilog language, before running marketing for Novas Software, noted for the Verdi product line, which became Springsoft and is now part of Synopsys.

Dave holds a Bachelor of Science degree in Electronic Computer Systems from the University of Salford and a Master of Science degree in Microelectronics from Brunel University, both in the U.K., and an MBA from Boston University.