模可以变计数器。可以实现任意模输入。采用VHDL文本编写。-Mode can be turned counter. Any mode input can be achieved. Text prepared by using VHDL.

十进制计数器（异步置数）及七段数码管显示系统，VHDL语言-Decimal Counter (Asynchronous Set the number) and the seven-segment LED display system, VHDL language