DDR存储器单粒子翻转试验及加固设计研究进展

Research progress on single event upset test and hardened design of DDR memory

概述了国内外对DDR存储器单粒子翻转试验与加固设计的研究历史及现状,并对其未来趋势进行展望.国内外研究人员开展了许多DDR存储器单粒子翻转相关试验,对各代DDR存储器的单粒子翻转截面和翻转阈值进行统计对比.通过对试验过程及其结果进行分析总结,研究工艺制程、存储容量及辐射剂量与单粒子翻转截面间的关系,发现随着DDR存储器工艺尺度的缩小、存储容量的增大,其对单粒子翻转的敏感度也逐渐增大.现有的DDR存储器抗单粒子翻转加固主要分为工艺加固和设计加固,包括SOI工艺、版图加固、电路冗余和纠错码等.简述了各类加固方法的机理,分析了各类加固方法的优势及存在的不足,并重点介绍了更具有普适性的纠检错算法加固,包括片上纠错码和EDAC(Error Detection and Correction)IP核.通过对几种典型的纠错码在纠检错能力、时间延迟、面积开销和功耗上加以对比,发现SEC-DED(Single Error Correction-Double Error Detection)海明校验码可用于纠正单粒子单位翻转,正交拉丁方码在纠正单粒子多位翻转方面优势显著,这为后续提出新的DDR存储器抗单粒子翻转加固方法提供了思路.

This paper summarizes the research history and current situation of DDR memory single event upset experiments and hardened design at home and abroad,and forecasts its future trend.Researchers at home and abroad have carried out many experiments related to single event upset of DDR memory,and made statistical comparisons of the cross-section and upset threshold of each generation of DDR memory.Through the analysis and summary of the experimental process and results,the relationship between the process,storage capacity,radiation dose and the single event upset cross-section is studied.It was found that with the shrinking of the DDR memory process scale and the increase of the storage capacity,its sensitivity to single event upset also gradually increased.The existing anti-single event upset hardening of DDR memory is mainly divided into process hardening and design hardening,including SOI(silicon-on-insulator),layout hardening,circuit redundancy and error correction code,etc..The mechanisms of various hardended methods were briefly explained,and the advantages and disadvantages of them were analyzed,and it focused on the hardened design of more universal error correction and detection algorithms,including on-die error correction codes and EDAC(Error Detection and Correction)IP cores.Compared with the detection capability,time delay,area overhead and power consumption of typical error correction codes,it is found that the SEC-DED(Single Error Correction-Double Error Detection)Hamming check code can be used to correct single bit upset,and the orthogonal Latin square code has significant advantages in correcting multiple bit upsets.It provides an idea for the subsequent proposal of a new DDR memory anti-single event upset hardened design.