1111序列检测的设计VHDL代码，用状态机实现111序列检测的设计，如果检测到正确的序列，则led灯亮起，否则熄灭-1111 Sequence Detection design VHDL code, using the state machine to achieve 111 Sequence Detection design, if it detects the correct sequence, led lights, otherwise extinguished