Development Of USB Host Conroller Driver Based On Embedded Linux

The technology of USB is widely applied in embeded system due to its high speed of transfer,extensibility,low resoure consumption,support for plug-and-play as well as hot plugging,which truly embody the removability and convenience of data exchange.However,embeded systems usually don't support the function of a USB host,thus the date exchange between embeded USB devices need to be PC centred and the point-to -point data exchange between devices can't be achieved.At this point,the research on embeded USB host system is of practical value and great significance.This paper works over the development of driver of embeded USB host cotroller.This paper takes USB host controller ISP1161A1 as its object of research,which is based on the EXA-400 embeded development platform of Beijing eflag corporation and embedded linux system.Firstly,the embedded linux platform based on the hardware has been constructed,namely,the porting of boot loader,linux kernel and root file system.After analyzing USB communication principle,OHCI specification and Linux USB subsystem,aimed at isochronous transfer and control transfer in the USB protocol,the driver for embeded USB host controller is designed and implemented,Secondly,which is based on the penetration of ISP1161A1,including mainly initialization module interupt module,root hub module and so on.Finally,the test of USB host driver is completed by the implementation of video capture system based on USB camera.With this result of the test,a conclusion can be safely made that the expectant objective is well achieved,namely,the successful realization of transfer of video captured by USB camera with the host controller driver for ISP1161A1 and isochronous transfer as well as control transfer in the USB protocol.