Subversion Repositories xilinx_virtex_fp_library

`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company: 	UPT	
// Engineer: 	Constantina-Elena Gavriliu
// 
// Create Date:    18:56:11 10/07/2013 
// Design Name: 
// Module Name:    special_cases
// Project Name: 
// Target Devices: 
// Tool versions: 
// Description: Compute corresponding special cases (exceptions)
//				//do not take into consideration cases for which the operation generates a NaN or Infinity exception (with corresponding sign) when initial "special cases" are not such exceptions
// Dependencies: 	SinglePathFPAdder
//
// Revision: 
// Revision 0.01 - File Created
// Additional Comments: 
//
//////////////////////////////////////////////////////////////////////////////////
module special_cases		#(	parameter size_exception_field = 2'd2,
									parameter [size_exception_field - 1 : 0] zero 			= 0, //00
									parameter [size_exception_field - 1 : 0] normal_number= 1, //01
									parameter [size_exception_field - 1 : 0] infinity		= 2, //10
									parameter [size_exception_field - 1 : 0] NaN				= 3) //11
								( 	input [size_exception_field - 1 : 0] sp_case_a_number,
									input [size_exception_field - 1 : 0] sp_case_b_number,
									output reg [size_exception_field - 1 : 0] sp_case_result_o); 
 
	always
		@(*)
	begin
		case ({sp_case_a_number, sp_case_b_number})
			{zero, zero}: 							sp_case_result_o = zero; 
			{zero, normal_number}: 				sp_case_result_o = normal_number;
			{zero, infinity}: 					sp_case_result_o = infinity;
			{zero, NaN}: 							sp_case_result_o = NaN;
 
			{normal_number,zero}:				sp_case_result_o = normal_number; 
			{normal_number,normal_number}:	sp_case_result_o = normal_number; 
			{normal_number,infinity}:			sp_case_result_o = infinity; 
			{normal_number,NaN}:					sp_case_result_o = NaN; 
 
			{infinity, zero}: 					sp_case_result_o = infinity; 
			{infinity, normal_number}: 		sp_case_result_o = infinity; 
			{infinity, infinity}: 				sp_case_result_o = infinity; 
			{infinity, NaN}: 						sp_case_result_o = NaN; 
 
			{NaN, zero}: 							sp_case_result_o = NaN; 
			{NaN, normal_number}: 				sp_case_result_o = NaN; 
			{NaN, infinity}: 						sp_case_result_o = NaN; 
			{NaN, NaN}: 							sp_case_result_o = NaN; 
			default:									sp_case_result_o = zero;
		endcase
	end
 
endmodule