NAND Flash 图像记录系统底层写入控制技术

为提高图像记录系统中 NAND flash 阵列的存储带宽,分别研究和实现了 NAND flash 的片内交叉写入、片内并行写入和片内交叉并行写入控制技术,在此基础上提出了片内交叉写入和片外2级流水线结合的写入方法,该方法利用两组 NAND flash 片内交叉写入的命令地址和数据加载时间来填补烧写时间.最后用硬件方式在 FPGA中分别实现了上述各种写入控制方式的控制器.实验结果表明:本文实现的片内并行写入和片内交叉并行写入是普通写入方式速度的1.48903倍和3.27706倍,而本文提出的写入控制方法的写入速度是普通写入方式的3.96038倍,高于片外4级流水线的性能情况下,将 FPGA 管脚资源占用节省20%,有效降低了成本和记录系统实现难度.

Write Control Technology of NAND Flash Image Recording System

To enhance the write bandwidth of NAND flash image recording system, the NAND flash on-chip write technologies of interleave, interleave two plane and two plane are researched and implemented respectively. Then, a new method based on NAND flash on-chip interleave write and off-chip 2 level pipelining is proposed, which utilizes the interleave load time of two NAND flash groups to fill the programming time. Finally, the controller with each write mode is realized in FPGA in the way of hardware. The experimental results show that on-chip two plane write speed and on-chip interleave two plane write speed are 1.489 03 times and 3.277 06 times of ordinary write speed respectively. However, the write speed of method proposed by this paper is 3.960 38 times of ordinary write speed, slightly higher than the 3.958 81 times of traditional off-chip 4 level pipelining. Moreover, proposed method can save 20% FPGA pin resources, and lower the cost and recording system realizing difficulty.