P5-34 4bit 減法器 適用於DE2-70實驗板

4bit 減法器 適用於DE2-70實驗板

減法器

module Full_sub_4bit (SW, LEDR, LEDG);

input [17:0] SW; // toggle switches

output [17:0] LEDR; // red  LEDS   

  output [7:0] LEDG; // green LEDs

  

//set original program input , output 

wire [3:0]X, Y; 

wire Bin;

wire [3:0]Dif;

    wire Bout;

wire Bout1,Bout2,Bout3;

   

    //mapping to hardware 

    assign LEDR = SW;

    

    //assign SW to input 

    assign Y=SW[3:0];

    assign X=SW[7:4];

    assign Bin=SW[17];

    

    

    

    //  X - Y -Bin = Bout , Dif       

//Assign difference and borrow

//full_sub_1bit(X, Y, Bin, Dif, Bout);

full_sub_1bit UUT1 (.X(X[0]),.Y(Y[0]),.Bin(Bin),.Dif(Dif[0]),.Bout(Bout1));

full_sub_1bit UUT2 (.X(X[1]),.Y(Y[1]),.Bin(Bout1),.Dif(Dif[1]),.Bout(Bout2));

full_sub_1bit UUT3 (.X(X[2]),.Y(Y[2]),.Bin(Bout2),.Dif(Dif[2]),.Bout(Bout3));

full_sub_1bit UUT4 (.X(X[3]),.Y(Y[3]),.Bin(Bout3),.Dif(Dif[3]),.Bout(Bout));

    assign LEDG[3:0]=Dif;

    assign LEDG[4]=Bout;

endmodule

//=============================================

//*original program

//-------------------------------------

//Filename : fadd1_df.v

//-------------------------------------

module full_sub_1bit(X, Y, Bin, Dif, Bout);

input X, Y, Bin;

output Dif, Bout;

//Assign difference and borrow

assign Dif = (((~X)&(~Y)&Bin)|((~X)&(Y)&(~Bin))|(X&(~Y)&(~Bin))|(X & Y & Bin));

assign Bout = (((~X)&Y)|((~X)&Bin)|(Y & Bin));

endmodule