Research On The Implementation Of Cubic B-spline Curve In Embedded Reconfigurable System

As a result of its excellent properties, Cubic B-Spline Curve is wildely used in drawing, graphics processing, computer graphics and so on. If the drawing of this curve is realized by Embedded Reconfigurable technology, the time of curve interpolation can be shortened and the cost can be reduced.Considering the Cubic B-spline interpolation joint realized by ARM and CPLD as the research object, this design has realized the build of platform and the design of hardware and software,and was verified finally. The main work of this design as follows:First of all, the Embedded Reconfigurable technology platform combined by ARM and CPLD was built, and the main design contains two parts: the peripheral devices design of the ARM side, such as power module, SDRAM, NOR Flash,UART, etc.; the design of interface between ARM and CPLD. As for such interface,two dual ports RAM implemented in CPLD were used to connect to the SMC(Static Memory Controller) in ARM for the comunication between ARM and CPLD, and some GPIO(General Purpose Input/Output) in ARM were used to be control signal lines.Then, the mathematical theory of the cubic B-spline curve and the application of the equal parameter segmentation algorithm and the inverse control vertex in the cubic B-spline curve were studied. Then, aiming at the above research, a combination method of the equal parameter segmentation algorithm and the Embedded Reconfigurable technology was designed.In this method, the recursive calculation in the algorithm above was implemented in CPLD, for achieving the full advantages of CPLD; the coefficient and recursive initial value calculation that contains a large number of multiplication and division was implemented in ARM that has rich interfaces and easy to interact with CPLD, because if this part also was implemented in CPLD, a lot of resources of CPLD would be occupied.Then, software in ARM was designed to complete the calculation of initial value used to recursiion calculation, and hardware modules(dual port RAM, Algorithm implementation module and controller module) in CPLD was designed to complete the reading of initial value and recursion calculaton. Then the designs in the ARM and CPLD were simulated.Finally, the design was tested on the actual Embedded Reconfigurable technology platform. The linear interpolation, parabolic interpolation and circular interpolation were tested and interpolation error was analyzed. The result of test and analysis was that the hardware and software designed can run normally, and can realize the interpolation calculation of the cubic B-spline curve successfully through the algorithm of equal parameter segmentation.