The Development Of Embedded Usb Host And Realizing The Function Of Mass Storage Class

USB interface device has the characteristic of convenient-use , high-speed and it supports to use once it's inserted in PC. The development of USB devices is difficult because of the annoying protocol. How to apply USB to embedded system and realize communication of point-to-point. It has became the hot of USB research field now.This thesis introduced the Host-Slave controller SL811HS and the application in the embedded system . In the base of introducing the characteristic of this chip, this thesis mainly explained this chip how to identify the flash disk and how to write data to the flash disk according to several protocols. These protocols include FAT32 File System Specification , USB Specification and UFI Mass Storage Class.We adopted the AT89C55 which is compatible with MCS-51 products entirely, except the Host controller SL811HS. AT89C55 has 20K bytes of in-system reprogrammable flash memory. So we needn't to extend the RAM and simplify the hardware.This system has realized the data storage for the flash disk and it has the characteristic of high-speed and mass storage . For the slave host it has the simple protocol of serial bus which would fit the demands of general purpose of data storage system.