面向MTJ的硬判决信道量化器设计与应用  

Design and application of hard decision channel quantizer for MTJ

作　　者：唐慧琴 赖怡桐 刘静华 陈平平 王少昊 TANG Huiqin;LAI Yitong;LUI Jinghua;CHENG Pingping;WANG Shaohao(Jinjiang Joint Institute of Microelectronics,Fuzhou University,Jinjiang 362200,Fujian,China)

机构地区：[1]福州大学晋江微电子研究院,福建晋江362200

出　　处：《微电子学与计算机》2022年第10期118-125,共8页Microelectronics & Computer

基　　金：国家重点研发计划(2018YFB0407603)。

摘　　要：磁随机存储器(MRAM)利用磁隧道结(MTJ)的高、低阻态来储存二进制信息,并常以MTJ参考电阻网络用作硬判决门限.MTJ阻态的阻值易受工艺偏差、电压、温度(PVT)因素影响,对大PVT范围内MRAM读操作的可靠性提出了挑战.本文提出一种基于MTJ参考电阻网络方案的硬判决信道量化器模型,考虑了温度、工艺波动等关键参数对MTJ不同阻态阻值的影响.通过比较由七种MTJ参考电阻组合所提供的硬判决门限,发现在MTJ工艺偏差6%~20%、温度233 K~400 K区间内,2(R_(P)//R_(AP))参考网络提供的判决门限可实现逼近最大化互信息量化方案的平均读决策错误率,且在大温度、工艺波动范围下展现出良好的跟随性.通过将上述一位硬判决信道量化方案应用在面向MTJ级联信道的纠错编码方案分析中,结果表明,在上述温度和工艺偏差范围内,所提出的2(R_(P)//R_(AP))硬判决门限在不同纠错算法下逼近于最大化互信息量化的理论最佳方案,并且短码的里德-索洛蒙(BCH)(127,92,5)码的解码性能优于低密度奇偶校验(LDPC)码和极化(Polar)码.Magnetic random access memory(MRAM)uses the high and low resistance states of magnetic tunneling junction(MTJ)to store binary information,and the MTJ reference resistor network is often used as the hard decision threshold.MTJ resistance is easily affected by process deviation,voltage and temperature(PVT),which challenges the reliability of MRAM read operation in large PVT range.In this paper,a hard decision channel quantizer model based on MTJ reference resistance network scheme is proposed.The influence of key parameters such as temperature and process fluctuation on different resistance values of MTJ is considered.By comparing the hard decision thresholds provided by seven MTJ reference resistor combinations,it is found that the decision thresholds provided by 2(R_(P)//R_(AP))reference network can achieve the average read decision error rate of the approximate maximum mutual information quantization scheme in the range of MTJ process deviation of 6%~20%and temperature of 233K~400K.Moreover,it shows good following performance under large temperature and process fluctuation range.The results show that the proposed 2(R_(P)//R_(AP))hard decision threshold approximates the theoretical optimal scheme of maximum mutual information quantization under different error correction algorithms within the above temperature and process deviation range.Moreover,the decoding performance of BCH(127,92,5)codes is better than that of LDPC and Polar codes.

关 键 词：磁隧道结(MTJ) 信道模型 信道量化器 纠错编码(ECC) 

分 类 号：TP333[自动化与计算机技术—计算机系统结构]