按动开发板键盘某个键CPLD将拨码开关的数据写入EEPROM的某个地址，按动另外一个键，将刚写入的数据 -- 读回CPLD，并在数码管上显-Pressing a button keyboard CPLD development board DIP switches, the data will be written to EEPROM in an address, pressing another key, the newly written data- read back CPLD, an