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;
 
			//stop condition
			if(bit == 0)
				done <= 1'b1;
 
			//reduce bit counter
			bit <= bit - 1;	
		end
	end
endmodule