問答題
下面是一個用狀態(tài)機設計的自動售貨機，one_dollar 代表投幣一元，half_doller 代表投幣五角。則下列說法正確的是 module machine(one_dollar, half_dollar, collect,half_out, dispense, reset,clk); parameter idle=2"b00, half=2"b01, one = 2"b10; input one_dollar, half_dollar, reset, clk; output collect, half_out, dispense; reg collect, half_out, dispense; reg[1:0] D; always @(posedge clk) begin if(reset) begin dispense=0; collect=0; half_out=0; D=idle; end else case (D) idle: if (half_dollar) begin dispense=0; collect=0; half_out=0; D=half; end else if(one_dollar) begin dispense=0; collect=0; half_out=0; D=one; end else begin dispense=0; collect=0; half_out=0; D=idle; end half: if(half_dollar) begin dispense=0; collect=0; half_out=0; D=one; end else if(one_dollar) begin dispense=1; collect=1; half_out=0; D=idle; end else begin dispense=0; collect=0; half_out=0; D=half; end one: if(half_dollar) begin dispense=1; collect=1; half_out=0; D=idle; end else if(one_dollar) begin dispense=1; collect=1; half_out=1; D=idle; end else begin dispense=0; collect=0; half_out=0; D=one; end default: begin dispense=0; collect=0; half_out=0; D=idle; end endcase end endmodule
A、飲料的售價為一元五角
B、該狀態(tài)機是mealy型狀態(tài)機
C、該狀態(tài)機的輸出只與當前狀態(tài)有關
D、當投入兩元錢后，找零五角，同時狀態(tài)機跳轉至idle狀態(tài)
