Digital Camera Study Based On DSC21

This thesis is one component of the study on the digital camera integrity and keytechnologies which is the key project of Chongqing Information and IndustryAdministration. The focus is to study the digital camera integrity based on DSC21 andCF card file system development concerned with conformity, JPEG code and decodearithmetic as well as its realization on the platform of DSC21.The study on the system of digital cameral hardware based on TMS320DSC21 andthe software are main contents of this paper. The system used DCS21 as the controllingchip with two-core structure(DSP 5409+ARM7), which is the mainstream structure ofimage processing on the digital camera. This is easy to extend and can be connectedseamlessly with CF card and SM card. In this paper, there are plenty of peripheralequipments, such as memory(SDRAM,FLASH,CF card), audio interface, infraedinterface(IrDA) and USB. All the programs are debugged on the platform of CCS. AndARM is aimed at system initialization, system setup, customer interface ,the executionof users'command, connecting performance and the control of whole system. DSP isaimed at processing image, with the two assistant processors in DSC21 accelerating theprocessing of image processing. Application programme about image collection hasbeen debugged on the digital camera platform, and programmer controlling OV2610CMOS sensor had been realized.Another content of the thesis is to develop the CF card file system, namely FAT filesystem, with FAT16 as the focus of this paper. The digital camera platform based onmicroprocessor or DSC21 can realize write and read of CF card file system. The papergives a detail introduction in FAT file system structure and the method to realize writeand read files.The JPEG coding and decoding on the platform of DSC21 is completed. JPEGcoding uses the assistant processor VLC and iMX in the DSC21. VLC can optimize andquantize computing and Huffman coding. And iMX is used as the special imageaccelerator, which can realize one-dimension and two-dimension digital filter andmatrix product. The two assistant processors can make the coding processing easy. Andthe decoding is realized by software. In order to validate the correctness of JPEG coding,first catch a frame of picture , and make JPEG coding in DSP, put the image data toSDRAM, write a JPEG file about the image data, then transfer the JPEG file data to CFcard. The file transfer to PC through USB interface. Through comparing the image afterbeing coding with the image being collected, the image being coding right is validated . In the addition, the study developing USB on the base of microprocessor is torealize PC reads and writes CF card file through USB interface. USB interface usesPDIUSBD12 made by Philips as the controlling chip, which conforms to the USB1.1standard. PC reads or writes CF card command from or to microcomputer through USB.In the interrupt program of USB, the microcomputer takes the corresponding operationin CF card according to command types and the data in CF card is transported to PCthrough the microcomputer. The study help to develop CF card file on the platform ofDSC21.