应用NAND型闪存的高速大容量图像存储器

摘要

针对单片闪存存储速度低,容量小,且存在无效块的问题,提出了一种高速大容量图像存储器的可靠性存储方案.通过分析闪存的组织结构和特征,并区分闪存写入无效块和非写入无效块,提出了基于CAM的数据分类匹配检测机制,以提高无效块信息匹配速度,并采用SRAM阵列冗余备份防止数据写入错误.在此基础上,提出了具有双总线结构的双流水线机制,多个流水线级出现写入无效块时,不中断流水线,保证存储器写入速度.通过搭建硬件平台进行实验测试,结果表明,该方法能够在5个系统时钟周期内实现无效块匹配,其持续存储速度达到960 Mb/s,持续读取速度达到1.152 Gb/s,擦除速度达到27.3 Gb/s,系统存储容量为80 GB.%In consideration of the low speed,small capacity and invalid block existing in a NAND flash,the reliability storage solutions of a high speed and high capacity image recorder based on NAND flash are proposed.After analyzing the structure and characteristics of NAND flash and separating written invalid block from non-written invalid blocks in the flash,the classified data matching and detection mechanism based on CAM are presented to raise the invalid block information matching speed,and a SRAM array backup is adopted to prevent data writing errors.Based on this,a dual pipelining mechanism based on a dual bus structure is proposed to prevent the interruption of writing pipelining when the invalid block is occurred in multiple pipelining grade during writing.An experiment based on a hardware platform is carried out,which indicates that the algorithm can identify the invalid blocks in 5 system clock periods and can offer the consistent storage speed of 960 Mb/s,consistent read speed of 1.152 Gb/s and the erasing speed up to 27.3 Gb/s.Moreover,the system storage capacity is up to 80 GB.