Miniature Intelligent Reading System Based On Dsp Research

With the rapid development of information technology, all kinds of portable electronic products and personal digital assistants are coming forth, the information source of these products partly roots in newspapers and journals, if the literal data could be acquired in optical scan mode instead of traditional keyboard input mode, human hands will be further liberated. On the other hand, the digital signal processor (DSP) specially designed for high-speed digital signal processing is playing an important role in the digital field, and the DSP with high processing speed and excellent operation performance is particularly adapted to image processing and character recognition .In consequence of this status, making use of new technology, this thesis researches into miniature intelligent reading system based on DSP and then presents a system solution of it.Firstly, the thesis summarizes and dissertates the theory and key technologies of miniature intelligent reading system, analyzes the characteristics, application prospects and the working proposal, and further more, brings forward a complete set of schemes, on this foundation, fulfills the hardware construction with the DSP serving as core processor.Afterwards, the minimum hardware system that supports TMS320VC5402 working is built. For the large amount of image data that requires to be processed at one time, the thesis expands the external memory, breaking the restriction of only 64K addressing range; According to system specialty of strong function and large program and the request of upgrade convenience, flash memory is used as storage medium, when DSP is powered up and reset, the user code is loaded from flash memory into external SRAM to run.Thirdly, the thesis describes the hardware implementation of function subsystem in detail, laying emphasis on the hardware circuit design of two modules including image capture and USB interface. For the image acquisition of optical scan mode, normally, CCD image sensor is used to capture image, but in our system, due to the system request of micromation and high integration, CMOS image sensor is adopted as the image collection device, and then the thesis gives a interface circuit between the chip and DSP and a control solution of image collection; Toward the information storage in our solution, DSP is directly linked to USB host chip and it is the DSP that accomplishes the processing of USB protocol and interface control so as to reduce the cost, minimize product cubage and consequently meet the requirement of system micromation; At the same time, the thesis probes preliminarily into USB OTG(On-The-Go) technology, whichoffers an approach between embedded machines including PDA, mobile phone, printer, digital camera and so on; In addition, some attempts on the other application area with TMS320VC5402 which was commonly used to voice processing and static image processing are done, for example, to arrange the chip to control LCD module directly.Finally, the thesis designs software system, gives the partition of software functional modules and the flow chart of main program.