During the 2023 User2User North America symposium, Ron Press, the technology enable director for Tessent, discussed clock generation methods with Tessent Streaming Scan Network (SSN). Press describes the different clock signals available in SSN and the four clock options you can use to optimize the shift capture and EDT clocks in each SSN host for your design, and what it means for timing closure. After his presentation, Press holds a Q&A session with the audience of test professionals.
Most SoC companies have started adopting the bus-based packetized test payload method of Tessent SSN. With SSN, any number of cores can be tested in parallel without having to align all the cores to shift and capture at the same time. This eliminates the need to balance timing with test clocks because each core it timed independently. Each core includes an SSN host node that drives one or more EDTs, takes the test information off of the SSN bus, and manages shift and capture. The user has several options when generating the internal clocks for each host node.