Research On Guiding Data Processing Unit Based On On-Borad Computer

The guiding data processing unit is an important part of the payload data processing system of the astronomical satellite, used to process image data of the guiding CCD camera. In this paper, the guiding data processing unit is designed based on Power PC8245 processor and Vx Works operating system, which i s the purpose of this paper.The guiding data processing unit implements CCD image data acquisition via LVDS interface. Then, data is output via CAN bus after processed in CPU. Meanwhile, the guiding data processing unit receives external control commands via CAN bus. According to these requirements, the system design is detailedly introduced first in this paper, and module division and realization are implemented then. The core hardware of the design is composed of Power PC8245 processor and virtex II FPGA, and Vx Works real-time operating system is the core of the software. In order to meet the reliability requirements for on-board computer, radiation-resistant applications are also introduced in this paper, to improve the reliability of the system.The guiding data processing unit communicates with external equipments though LVDS and CAN bus. This paper then presents detailed design of LVDS and CAN interfaces on FPGA, as well as Flash control interface, which is used for storing image correction data. Through the simulation and hardware test, the program on FPGA is properly verified.Since Board Support Package is the basis for an embedded operating system running on a platform, paper then introduces detailed design of Vx Works BSP for the hardware platform, including system and the underlying hardware configuration, as well as seial port driver and Flash driver development, to implement Vx Works running on Power PC8245.At the last of this paper, tests of all functional modules are performed respectively under Vx Works operating system, and the results demonstrate that all modules designed work well. The guiding data processing unit in this paper is a prototype design, and design will be continued to improve its function so that it can be applied to the space mission in the future.