1989 Reports

Psi: A Silicon Compiler for Very Fast Protocol Processing

Abu-Amara, H.; Balraj, Timothy S.; Barzilai, T.; Yemini, Yechiam

Conventional protocols implementations typically fall short, by a few orders of magnitude, of supporting the speeds afforded by high-speed optical transmission media. This protocol processing bottleneck is a key hurdle in taking advantage of the opportunities presented by high-speed communications. This paper describes PSi, a silicon compiler that transforms formal protocol specifications into efficient VLSI implementations. PSi takes advantage of the parallelisms intrinsic to a given protocol to accomplish very high-speed implementations. Initial application of PSi to the IEEE 802.2 (logical link control) leads to processing rates in the order of 106 packets per second (p/s). The 802.2 was selected as a benchmark of complexity; light-weight protocols can accomplish even higher processing rates, reaching the limits set by chip clock rates (i.e., a packet per cycle). These speeds significantly exceed typical of software implementations (up to a few hundred p/s) or special hardware-assisted implementations (up to a few thousands p/s). More importantly, at these rates when the packet size is 103-4 bits the protocol throughput of 109-10 bits/sec reaches the limiting throughput afforded by memory technology. Thus, the protocol processing bottleneck is pushed to the ultimate bounds set by VLSI technologies.