题解 | #自动售卖机#

自动售卖机

https://www.nowcoder.com/practice/487953e6d3e3434988e0dd6960b6c9f8

`timescale 1ns/1ns

module sale(
   input                clk   ,
   input                rst_n ,
   input                sel   ,//sel=0,5$dranks,sel=1,10&=$drinks
   input          [1:0] din   ,//din=1,input 5$,din=2,input 10$
 
   output   reg  [1:0] drinks_out,//drinks_out=1,output 5$ drinks,drinks_out=2,output 10$ drinks
   output	reg        change_out   
);

//首先要知道哪些情况要使用状态机
//购买B饮料(10块),先投5块之后,后面接着投5块,还是投10块
reg [1:0] state;

always@(posedge clk or negedge rst_n)
  if(!rst_n) 
    begin drinks_out <= 2'd0; change_out <= 1'd0; state <= 2'd0;end
  else case(sel)
    1'd0://购买A饮料,情况很简单
        case(din)
        2'd0:
            begin drinks_out <= 2'd0; change_out <= 1'd0; end
        2'd1:
            begin drinks_out <= 2'd1; change_out <= 1'd0; end
        2'd2:
            begin drinks_out <= 2'd1; change_out <= 1'd1; end
        default:begin drinks_out <= 2'd0; change_out <= 1'd0; end
        endcase
    1'd1:
        case(din)
        2'd0:
            begin drinks_out <= 2'd0; change_out <= 1'd0; end
        2'd1:
            begin 
                if(state==2'd0)
					//买B饮料,第一次投5块,state==1记录一下
                    begin drinks_out <= 2'd0; change_out <= 1'd0;state <= 2'd1;end
                else if(state==2'd1)
					//买B饮料,第二次投5块,state==0,返回初始状态
                    begin drinks_out <= 2'd2; change_out <= 1'd0;state <= 2'd0; end
            end
        2'd2:
            begin
                if(state==2'd0)
					//买B饮料,第一次投10块。输出后state==0,返回初始状态
                    begin drinks_out <= 2'd2; change_out <= 1'd0;state <= 2'd0; end
                else if(state==2'd1)
					//买B饮料,第一次投过5块后,再投10块。输出后state==0,返回初始状态
                    begin drinks_out <= 2'd2; change_out <= 1'd1;state <= 2'd0;end
            end
        default:begin drinks_out <= 2'd0; change_out <= 1'd0; end
        endcase
    default:begin drinks_out <= 2'd0; change_out <= 1'd0; end
    endcase

endmodule

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05-12 17:00
门头沟学院 Java
king122:你的项目描述至少要分点呀,要实习的话,你的描述可以使用什么技术,实现了什么难点,达成了哪些数字指标,这个数字指标尽量是真实的,这样面试应该会多很多,就这样自己包装一下,包装不好可以找我,我有几个大厂最近做过的实习项目也可以包装一下
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