4、以下的描述中,必然是对Mealy型状态机的描述的是?
A.always @(*) case (state) S0: begin out = 0; if (in) next_state = S1; else next_state = S2; end ……#B.always @(*) case (state) S0: begin if (in) next_state = S1; else next_state = S0; end ……#C.always @(*) case (state) S0: begin if (in) begin next_state = S1; out=1 end else next_state = S0; end ……#D.以上答案均不正确