NetSpeed Systems Utilizes Cadence Solutions for Efficient Verification of Complex IP Products

NetSpeed Systems is a provider of scalable, coherent, on-chip network (NoC) IPs to system-on-chip (SoC) designers across a wide range of markets, from mobile to high-performance computing and networking. The company's NoC platform delivers significant time-to-market advantages through a system-level approach, a high level of user-driven automation, and state-of-the-art algorithms. NetSpeed developed Gemini, its cache-coherent NoC solution, to address two key limitations in existing hardware-based coherency solutions: performance and scalability. Gemini supports all three levels of coherent traffic—cache coherent, I/O coherent, and non-coherent traffic—in a single NoC, offering high performance, scalability, and configurability for a wide range of applications.

NetSpeed Systems, a provider of scalable, coherent, on-chip network (NoC) IPs to system-on-chip (SoC) designers, faced significant challenges in designing its cache-coherent NoC solution, Gemini. The product's flexibility allowed for an endless number of configurations, necessitating an astronomical number of test cases. This posed a risk of introducing prolonged delays in the development schedule. Additionally, the coherency verification process was deeply stateful, requiring long runs to accumulate internal chip states and hit corner cases. Coherency bugs were unforgiving, with a single bug capable of bringing down the entire product. The vast verification space, including a large warm-up period and the need to expose bugs that manifest only after millions of cycles, added to the complexity. The company needed a solution that could provide comprehensive test coverage in this massive verification space, generate all possible NoC configurations, provide an intelligent, coordinated stimulus for the test cases, and enable efficient debugging and reproduction of errors.

NetSpeed Systems turned to Cadence's Palladium XP acceleration/emulation platform as part of its multi-layered approach to exhaustively verify Gemini. The company adopted a 'depth and breadth' verification strategy that used Cadence Incisive simulation to quickly cover large numbers of configuration and emulation to validate complex time-dependent scenarios. The Palladium XP platform allowed NetSpeed to run more realistic workloads and test more complex SoC power interactions that were not possible in simulation. Self-checking stimulus loaded onto the Palladium XP platform enabled running billions of instructions, helping NetSpeed reach further faster and flush out elusive bugs. The methodology also enabled NetSpeed to replay emulation runs in Incisive simulation, matching every cycle between the two. NetSpeed used its in-house NocWeaver software to generate more than 1000 NoC designs every night. Using the Palladium XP platform, NetSpeed was able to run much longer, exhaustive tests. Implementation and bring-up of the Palladium testing environment took less than a week, and testing that would normally have spanned weeks was completed in minutes.

• The use of Cadence's Palladium XP platform has become an integral component of NetSpeed's solution for verification challenges. The platform has enabled comprehensive testing that would otherwise be infeasible, mitigating business risk and helping to build customer confidence in NetSpeed's products. The ability to run more realistic workloads and test more complex SoC power interactions has enhanced the quality of the product. The ability to replay and debug in a timely manner has proved especially crucial, improving the efficiency of the verification process. NetSpeed plans to use the Palladium XP platform on future product releases, demonstrating the significant operational benefits derived from its use.

• Increased validation speed hundreds of times faster compared to simulation
• Enabled exhaustive test coverage of a massive verification space
• Improved validation team productivity: operations that previously took weeks were completed in minutes