Subversion Repositories vtach

`timescale 1ns / 1ps

/* Find 9's compliment number 17 and 13 bit versions */

/* These pass positive numbers unchanged but convert negative ones or

   if you pass in a 9's compliment # you get the vtach format number

        back */

module bcdneg17(

    input [16:0] x,

    output [16:0] y

    );

 wire [15:0] yn;

 assign y[16]=x[16];

 bcdincr negplus({4'h9-x[15:12], 4'h9-x[11:8], 4'h9-x[7:4], 4'h9-x[3:0]},yn);

 assign y[15:0]=(x[16])?yn:x[15:0];

endmodule

module bcdneg13(input [12:0] x, output [12:0] y);

 wire [11:0] yn;

 assign y[12]=x[12];

 bcdincr negplus({ 4'h9-x[11:8], 4'h9-x[7:4], 4'h9-x[3:0]}, yn);

 assign y[11:0]=(x[12])?yn:x[11:0];

endmodule