The Pxa255 Processor, Usb Host Control

Ever since its birth,the USB has been in continuously self-perfecting, USB technology keep coming and are used in practice,such as USB1.1,USB2.0,USB OTG1.0,PowerUSB,WUSB,etc. USB technology is developing towards more extensive. With the advent of USB new technology, the USB application domain is more extensive. Because of the import of USB technology,embedded system can according USB bus choice to implement more functions.PXA255 is a high integrated 32bits RISC processor,a more extensive used processor of XScale processor family.PXA255 is a high performance and low power consumption device,provide industry-leading MIPS/mW. It integrated LCD controller,audio encoder/decoder,MultiMediaCard Controller,etc;facing the embedded market: Handheld device,wireless net,strorage device,etc. In PXA2SS there is a USB Device Controller only,which make PXA255 can be visited and controlled by other USB host.This paper implement USB host interface faction for PXA255.On the board, a integrated USB host controller are used by PXA255,PXA255 control this device to implement visit and control USB device. The hardware equipment is XSBase255, the software is ADS1.2.The study is devided into two part:PXA255 and USB host control function of CY7C67300.Firstly this paper is based on the study of PXA255 processor, study the system initialization programme design,especially memory management,implement PXA25S storage space remap, programme style and programme process. Secondly , introduce the hardware connection and software communication between PXA255 and CY7C67300. PXA255 use CY7C67300 to obtain USB device information,such as device descriptor, configuration descriptor,etc;obtain and parse USB mouse's report descriptor. Finally introduce how to use USB mouse's input report to implement mouse's movement on LCD and button manipulation.