Improvement of Line Coding Overhead Targeting Both Run-Length and DC-Balance

摘要

High-speed serial data communication is now very popular for connecting various resources in high-performance computing systems. In such high-speed serial links, a line coding is important to control the run length (RL) and the running disparity (RD), because a large run length causes insufficient transitions on data-links that make it difficult to perform reliable clock and data recovery (CDR), and a bounded running disparity is needed for maintaining the DC-balance of data links. These requirements for a line coding, however, cause additional bits to be transmitted, which decreases the throughput of data transmission. This paper presents a new approach to reducing the overhead of line codings, guaranteeing the bounded run length and running disparity. Our experimental results show that the proposed technique reduces the overhead by up to 98% compared to conventional line codings and by up to 48% compared to a latest low-overhead line coding.