Design Of Wireless Data Terminal System Based On PXA270

With the development of the Internet and the coming of the post-PC era, the embedded system is much more widely used. Various new embedded microprocessors and embedded products emerge one after another incessantly. And the embedded technology based on ARM has become a highlight in the filed of embedded system. PXA270 is an embedded microprocessor based on ARMv5te and XScale architecture. PXA270 has excellent multimedia processing performance and several of peripheral controller interfaces and it is widely used in such situations as handheld device, set-top box, industrial control and so on.This paper studies a wireless data terminal system based on PXA270. It has the characteristics of small volume, low cost, high stability, high transmit speed rate and so on. The system is able to access IEEE 802.1 lg standard WIFI network, so it can receive the data acquired by distributed sensor network, put the data onto LCD by means of GUI system and provide a friendly human-computer interaction function. The data terminal can extend its applications in many fields such as remote monitoring and so on, and it has a broad market and application prospects.This paper discusses the core and peripheral hardware design of PXA270 microprocessor, software design and debug method based on Linux 2.6 embedded OS in detail. In terms of hardware, the function of each module, the circuit schematic design and the analysis of high speed multilayer PCB design are introduced in depth. In terms of software, system porting and customization method are carried out and a number of key technologies in the software development are discussed, including: the Bootloader porting, crypto memory chip and SD card encryption support in the u-boot, the principle of writing YAFFS2 file system, embedded Linux 2.6 customization, ALSA audio library porting, building the application interface by QT-Embedded, embedded software debug method and so on. On this basis, the paper also describes the standard of IEEE 802.11 protocol and studies the network communication implementation in the embedded Linux systems.