Research And Development Of USB Bus Client Driver In WINCE.Net System

The direction of the research in this paper is to study the related theory in developing USB bus drivers in WinCE.Net embedded OS and this item comes from one of the applications in the industrial controller field studying by Beijing Shouke Catch Ecletronics Corp.. USB bus is the most important standard connection method between the computers and the multifarious functional device products,so the ability to support USB bus of the industrial controller with WinCE.Net is a so outstanding advantage that they can have more choices to connect USB bus functional devices.Consequently,this technique is of academic and application significance. During the period of the research,since the product about this juncture is relatively few, the paper made analogies during developing USB device driver between WinCE.Net and the interrelated OS such as Windows, Linux etc.and then studied the online English and other related documents while analyzing sorts of source codes of drivers in the OS,based on which,the paper found the method to develop USB bus device driver under the stream interface strategy. The main results are the following: ⑴USB bus system differs from other conventional serial bus in that its host and device are an organic unitand the functional device is made with the appointed device class definition,so the device driver should be developed according to the device definition and the protocol. ⑵After analyzing the ability of WinCE.Net to support to USB bus,the paper puts forward a viable strategy to develop USB bus device driver and implement a real driver according to it.Since the application areas are different,in contrast with OS such as Windows,Linux etc.,the driver development mechanism of the embedded OS is simpler than them and we can,in fact,develop the device drivers according to the actual conditions with flexible ways.The strategy issued by this paper is "Stream Interface Drivers",which can be used as a usual developing method on the USB bus devices of stream data and type-related. ⑶To analyse the configuration process between OS protocol driver and USB bus device and the matching process between driver and the correspond device function interface.They are one of the most important and creative products in this paper and can have effects on all the USB bus devices as a general rule.Before the device driver can control the device,the device must pass six protocol phases during configuration process and after that, when the device driver is matched by protocol with the corresponding device,the host can control the real target device.