乘法器、除法器、多路选择器、编码器、BCD码转换、加法器、减法器、状态机、四位比较器、数码管、串口、跑马灯、电子钟-Multiplier, divider, multiplexer, encoder, BCD code converter, adder, subtractor, state machines, four more players, digital control, serial port, marquees, electronic clock