Subversion Repositories fixed_point_arithmetic_parameterized

`timescale 1ns / 1ps

//////////////////////////////////////////////////////////////////////////////////

// Company: 

// Engineer: 

// 

// Create Date:    19:39:14 08/24/2011 

// Design Name: 

// Module Name:    divider 

// Project Name: 

// Target Devices: 

// Tool versions: 

// Description: 

//

// Dependencies: 

//

// Revision: 

// Revision 0.01 - File Created

// Additional Comments: 

//

//////////////////////////////////////////////////////////////////////////////////

module qdiv(

        input [N-1:0] dividend,

        input [N-1:0] divisor,

        input start,

        input clk,

        output [N-1:0] quotient_out,

        output complete

        );

        //Parameterized values

        parameter Q = 15;

        parameter N = 32;

        reg [N-1:0] quotient;

        reg [N-1:0] dividend_copy;

        reg [2*(N-1)-1:0] divider_copy;

        reg [5:0] bit;

        reg done;

        initial done = 1;

        assign quotient_out = quotient;

        assign complete = done;

        always @( posedge clk )

        begin

                if( done && start ) begin

                        done <= 1'b0;

                        bit <= N+Q-2;

                        quotient <= 0;

                        dividend_copy <= {1'b0,dividend[N-2:0]};

                        divider_copy[2*(N-1)-1] <= 0;

                        divider_copy[2*(N-1)-2:N-2] <= divisor[N-2:0];

                        divider_copy[N-3:0] <= 0;

                        //set sign bit

                        if((dividend[N-1] == 1 && divisor[N-1] == 0) || (dividend[N-1] == 0 && divisor[N-1] == 1))

                                quotient[N-1] <= 1;

                        else

                                quotient[N-1] <= 0;

                end

                else if(!done) begin

                        //compare divisor/dividend

                        if(dividend_copy >= divider_copy) begin

                                //subtract

                                dividend_copy <= dividend_copy - divider_copy;

                                //set quotient

                                quotient[bit] <= 1'b1;

                        end

                        //reduce divisor

                        divider_copy <= divider_copy >> 1;

                        //reduce bit counter

                        bit <= bit - 1;

                        //stop condition

                        if(dividend_copy == 0)

                                done <= 1'b1;

                end

        end

endmodule