Beomseok Nam, Henrique Andrade, et al.
ACM/IEEE SC 2006
Assume that information is transmitted in parallel among many lines in such a way that an electrical transition represents a 1 and an absence of a transition represents a 0. The propagation delay in the wires varies and results in asynchronous reception. The challenge is to find an efficient communication scheme that will be delay-insensitive. One of the common solutions to this problem is to use a handshake mechanism. Namely, the transmitter sends the next vector only after getting an acknowledgment that the current vector was received. A natural question is: how does the receiver know that reception of the current vector is complete? This problem was solved by Verhoeff by using the so-called unordered codes. However, in practice, it is common that the communication lines are arranged in pairs (double-rail) such that the propagation delay on the lines within a pair is identical. In general, the lines can be arranged in groups (of size larger than 1) where transmission within a group is synchronized. We have created a few delay-insensitive schemes that take advantage of partial synchronization within groups. To achieve that, we have generalized to arbitrary alphabets the following known results: Sperner's theorem on unordered sets, Henry-Knuth's construction of balanced codes, and Berger's con- struction of unordered codes. Finally, we have focused on practice, and constructed a code that uses double-rail channels but has the advantage that it is a rate 3/4code as opposed to the rate 1/2double-rail code (that is the common code being used in real systems). © 1994 IEEE
Beomseok Nam, Henrique Andrade, et al.
ACM/IEEE SC 2006
Frank R. Libsch, S.C. Lien
IBM J. Res. Dev
Donald Samuels, Ian Stobert
SPIE Photomask Technology + EUV Lithography 2007
Hang-Yip Liu, Steffen Schulze, et al.
Proceedings of SPIE - The International Society for Optical Engineering