P6-19 8bit 2x1MUX 適用於DE2-70

P6-19 8bit 2x1MUX 適用於DE2-70

module _8bit_2x1Mux (SW, LEDR, LEDG , CLOCK_27 ,KEY );

input  [17:0] SW; // toggle switches

input  [7:0] KEY;     // Push bottom

input  CLOCK_27; //Clock 27MHz , 50Mhz

output [17:0] LEDR; // red  LEDS   

  output [7:0] LEDG; // green LEDs

  

  

//set original program input , output 

    //output [3:0] y;

    //input s;           //Select signal

    //input [3:0] a, b;  //Input data 

    

    wire [7:0] a,b;

    wire s;

    reg [7:0] y =8'bz ;

    //mapping to hardware 

    assign LEDR = SW;

    

    assign s=SW[17];

    assign a=SW[7:0];

    assign b=SW[15:8];       

always @ (s or a or b)

if (s)

y = b;

else

y = a;

    assign LEDG[7:0]=y;

endmodule