SD卡的SPI方式驱动，SPI方式简单速度也可以，很多处理器都有SPI功能，没有也可模拟。-SD card SPI mode driver, SPI is simple speed can, many processors have the SPI function, does not and can simulate.

很好的一篇论文，主要使用NAND FLASH设计一个sd卡系统。-The paper gives an implementation instance base on the design discussion. The implementation focuses on speed enhancement.

This is the second energy entropy matlab code, Using common plane wave expansion method, FIG simulation speed, distance, amplitude three-dimensional image.