FPGA时钟显示程序，可以按照正常的时间，频率可调，数码管显示00-00-00，中间的-可改。只要采用嵌套的循环结构实现-FPGA clock display program, you can follow the normal time, frequency adjustable, digital display 00-00-00, middle- can be changed. As long as the use of a nested loop structure to achieve