Pulse-mode link for robust, high speed communications
Merritt P. Miller, Greg Hoover, Forrest D. Brewer · 2008
This paper describes shape-preserving pulse-mode CMOS circuits for use in on-chip serial communication links. These links are competitive with conventional high-speed serial links but are simpler, more robust, and have remarkably small design overhead. In particular, they can be fabricated with limited voltage swings on minimum and medium wire sizes in highly scaled technologies as efficient point to point links. The key idea in this design is the notion of an ‘atomic’ pulse whose width and minimum period are preserved by circuit behavior, removing the jitter/length trade-offs of conventional techniques. Pulse-based data encoding removes the need for clock recovery or timing maintenance for time-scales larger than a single pulse. This allows quiescent link operation with no preamble, keep-alive, or channel encoding requirements. A prototype link design is developed and evaluated and is shown to be competitive for power, performance, and signalling robustness.