基于AT89S52和FAT16的SD卡读写系统设计  

SD Card Read/Write System Based on AT89S52 and FAT16

作　　者：张恒[1] 

机构地区：[1]山东大学

出　　处：《单片机与嵌入式系统应用》2009年第8期53-55,58,共4页Microcontrollers & Embedded Systems

摘　　要：采用SD卡的SPI通信模式,用单片机编程模拟SPI总线时序,实现AT89S52对SD卡的读写。利用晶体管加下拉电阻的方法实现SD卡与AT89S52的电平匹配。介绍了SD卡接口规范,SD卡SPI接口时的指令与响应时序。详细介绍了FAT16文件系统的文件组织与存储原理,以及SD卡指令结构。研究了软件模拟SPI接口时序的编程实现,给出了软件模拟SPI接口的汇编代码,以及单片机读写SD卡和读写FAT16文件系统的软件流程。The SPI mode of SD card is used for communication in the design. System SPI timing is simulated by programming. E-lectrical level matching problem between SD card and MCU is solved by transistor with pull-down resistor. SD card interface standard and command timing under SPI mode are introduced. FAT16 file system is introduced. SPI timing cimulation source code in assemble language is provided. Software flow chart of read/write of SD card and files under FAT16 file system is given.

关 键 词：FAT16 SD卡 SPI AT89S52 51单片机 

分 类 号：TP391.44[自动化与计算机技术—计算机应用技术]