使用VHDL编写语言，巧妙的利用计数器和循环输出一个坐标系，由于VHDL出现负数比较麻烦，全部由正数代替，输出一个原点在中心，半径128的256×256的坐标。方便坐标变换以及用此坐标做算法。-Use of VHDL language, clever use of counter and loop outputs a coordinate system, because VHDL negative too much trouble, all replaced by a positive number, the output an origin at the center, radius 128 256 256 coordinates. Convenient coordinate transformation and coordinate to do with this algorithm.