设计并实现一个随机数生成电路每 2 秒随机生成一个 0~999　之间的数字，并在数码管上显示生成的随机数。
2、为系统设置一个复位键，复位后数码管显示自己学号的后三位数字，2秒后再开始每2秒生成并显示随机数，可以不需要防抖(A random number generating circuit is designed and implemented to generate a random number between 0 and 999 every 2 seconds, and display the generated random number on the nixie tube.
2. Set a reset key for the system. After reset, the nixie tube will display the last three digits of its student number. After 2 seconds, it will start generating and displaying random numbers every 2 seconds. It can be without anti shake)