NAND Flash service lifetime estimate with recovery effect and retention time relaxation

A service life model of NAND flash and threshold voltage shift process is proposed to calculate the service life and endurance. The relationships among achievable program/erase （P/E） cycles, recovery time, bad block rate and storage time are analyzed. The achievable endurance and service life of a NAND flash are evaluated based on a flash cell degradation and recovery model by varying recovery time, badblock rate, and storage time. It is proposed to improve the service lifetime of solid state disk by both relaxing the bad block rate limitation and retention time while extending the recovery time. The results indicate that endurance can be improved by 17 times if the storage time guarantee is reduced from 10 a to 1 a with 10 5 s recovery time inserted between cycles.     

一种基于FPGA的雷达数字信号处理机设计与实现

结合具体的雷达导引头型号项目,从数字信号处理机的原理出发,根据项目的要求提出了一种基于DBF技术的某型导引头信号处理机设计方案,方案以Xilinx公司Virtex4SX55FPGA作为数字信号处理的核心器件,实现对6阵元阵列天线接收的回波信号进行实时采集和处理。对系统硬件和软件总体设计及基频信号产生模块、回波信号采集模块、控制信号产生模块和时钟电路模块的具体设计进行了详细介绍。最后在暗室环境对系统进行了测试,测试结果表明系统达到了设计要求。     

基于固态存储技术的DRFM设计

为了提高数字射频存储器（DRFM）的存取速度、存储深度和系统的灵活性,采用了模块化设计原则。以PXIE机箱为平台,运用固态存储技术实现信号的高速存取,完成了包括上、下变频模块、中频信号采集模块、中频信号还原模块、固态存储模块以及处理控制核心等电路的设计。重点研究固态存储技术和PXIE技术在DRFM中的应用,为进一步提高DRFM的性能提供了参考。