Cadence demonstrated its proprietary optical connectivity solution for PCIe 7.0 at the PCI-SIG DevCon 2024 earlier this month. The world's first demonstration of 128 GT/s PCIe 7.0 interconnection over optics is largely a proof-of-concept as the PCIe 7.0 specification is yet to be finalized. However, having a working optical connectivity solution for a standard that is set to be used towards the end of the decade clearly demonstrates Cadence's technical prowess.
During the event, Cadence demonstrated its 128 GT/s PCIe 7.0 IP's transmission and reception capabilities using a real-world, low-latency, non-retimed, linear optical connection. This setup consistently achieved a pre-FEC BER of ~3E-8, well within the PCIe specification requirement of 1E-6, making it the first stable demonstration of 128 GT/s over standard optical connectors. The receiver Eye PAM4 histograms, depicted on an image demonstrated by Cadence, exhibit excellent linearity and margin.
