Statistical eye diagram estimation method for 128b/130b-coded channel

Abstract

We propose statistical eye-diagram estimation method for 128b/130b-coded channel by using 1-Bytewise pre-calculation. It is inevitable process to predict channel's transmission characteristic, or quality before fabricating chips and backplane because it saves time and cost effectively. Eye diagram estimation method is one of the best methods to predict channel's quality so that various methods such as worst case eye diagram estimation, and single bit response (SBR) based methods have been proposed for fast and accurate estimation. However these methods does not consider encoder effect and assumes the same probability of '0' and '1' as 50 % at the transmitter. In high datarate and high bandwidth system, Sereializer/Deserializer (SerDes) is used to overcome the limitation and these kind of communication system utilize encoder. PCI express (PCIe) is one of the famous communication protocol in these days, and it uses 128b/130b encoder for recent gen 3 and gen 4. Because previous eye diagram estimations usually does not consider encoder effect, we propose more fast and accurate eye diagram method compared with commercial tool in this research. At the later chapter of the paper, we applied this method to some applications such as length effect and temperature effect.