FPGA实验板设计一个数字跑表。根据题目要求利用VHDL语言设计出一个系统，包括分频器，开关消抖，使能控制，计数器，锁存器，数据选择器及显示译码器。-FPGA experimental board design a digital stopwatch. According to subject the use of VHDL language to design a system, including the divider, switch debounce, enable control, c