Partially Systematic Constant-Weight Codes for Delay-Insensitive Communication

The increasing complexity and modularity of contemporary systems makes the availability of flexible and robust, yet efficient, module-level interconnect instrumental. Delay-insensitive codes are very attractive in this context. In this paper we explore the idea of composing hybrid coding schemes that combine the benefits of constant-weight codes, namely simple completion detection, with those of systematic codes, namely zero-effort decoding. Apart from showing how to systematically construct efficient hybrid codes, we elaborate in great detail on the cost-efficient and orphan-free implementation of completion detectors, as well as that of suitable encoders and decoders. A comparison of various concrete solutions in terms of coding efficiency as well as hardware overhead gives evidence for the benefits of our proposed approach, and at the same time serves as a repository for ready-made optimized solutions.