用 vhdl 设计含异步清零和同步时钟使能的十进制加法计数器。再用 vhdl 设计含异步清零和同步时钟使能的十进制加减可控计数器。 -With vhdl design with asynchronous clear and synchronous clock enable decimal up counter. Vhdl design and then synchronize with asynchronous clear and clock enable control counter d