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[/] [xilinx_virtex_fp_library/] [trunk/] [DualPathFPAdder/] [DualPathFPAdder.v] - Rev 18
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`timescale 1ns / 1ps ////////////////////////////////////////////////////////////////////////////////// // Company: UPT // Engineer: Constantina-Elena Gavriliu // // Create Date: 00:31:28 11/19/2013 // Design Name: // Module Name: DualPathFPAdder // Project Name: // Target Devices: // Tool versions: // Description: A ± B // //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: ClosePath.v // FarPath.v // special_cases.v // effective_op.v // // Revision: // Revision 0.01 - File Created // Additional Comments: // ////////////////////////////////////////////////////////////////////////////////// module DualPathFPAdder #( parameter size_mantissa = 24, //1.M parameter size_exponent = 8, parameter size_exception_field = 2, parameter size_counter = 5, //log2(size_mantissa) + 1 = 5) 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 parameter [1 : 0] FP_operation = 0, parameter [1 : 0] FP_to_int = 1, parameter [1 : 0] int_operation = 3, parameter pipeline = 0, parameter pipeline_pos = 0, // 8 bits parameter double_size_mantissa = size_mantissa + size_mantissa, parameter double_size_counter = size_counter + 1, parameter size = size_mantissa + size_exponent + size_exception_field) ( input [size - 1 : 0] a_number_i, input [size - 1 : 0] b_number_i, input sub, output[size - 1 : 0] resulted_number_o); wire [size_exception_field - 1 : 0] sp_case_a_number, sp_case_b_number; wire [size_mantissa - 1 : 0] m_a_number, m_b_number; wire [size_exponent - 1 : 0] e_a_number, e_b_number; wire s_a_number, s_b_number; wire [size_exponent : 0] a_greater_exponent, b_greater_exponent; wire [size_exponent - 1 : 0] exp_difference; wire [size_exponent : 0] exp_inter; wire [size_mantissa - 1 : 0] shifted_m_b; wire [size_mantissa - 1 : 0] initial_rounding_bits, inter_rounding_bits; wire eff_op; wire [size_mantissa : 0] unnormalized_mantissa; wire [size_mantissa-1 : 0] fp_resulted_m_o, cp_resulted_m_o; wire [size_exponent-1 : 0] fp_resulted_e_o, cp_resulted_e_o; wire [size_exception_field - 1 : 0] resulted_exception_field; wire resulted_sign; wire zero_flag; wire [4:0] sign_cases; reg intermediar_sign; assign e_a_number = a_number_i[size_mantissa + size_exponent - 1 : size_mantissa - 1]; assign e_b_number = b_number_i[size_mantissa + size_exponent - 1 : size_mantissa - 1]; assign s_a_number = a_number_i[size - size_exception_field - 1]; assign s_b_number = b_number_i[size - size_exception_field - 1]; assign sp_case_a_number = a_number_i[size - 1 : size - size_exception_field]; assign sp_case_b_number = b_number_i[size - 1 : size - size_exception_field]; //find the greater exponent assign a_greater_exponent = e_a_number - e_b_number; assign b_greater_exponent = e_b_number - e_a_number; //find the difference between exponents assign exp_difference = (a_greater_exponent[size_exponent])? b_greater_exponent[size_exponent - 1 : 0] : a_greater_exponent[size_exponent - 1 : 0]; assign exp_inter = (b_greater_exponent[size_exponent])? {1'b0, e_a_number} : {1'b0, e_b_number}; //set shifter always on m_b_number assign {m_a_number, m_b_number} = (b_greater_exponent[size_exponent])? {{1'b1, a_number_i[size_mantissa - 2 :0]}, {1'b1, b_number_i[size_mantissa - 2 :0]}} : {{1'b1, b_number_i[size_mantissa - 2 :0]}, {1'b1, a_number_i[size_mantissa - 2 :0]}}; effective_op effective_op_instance( .a_sign(s_a_number), .b_sign(s_b_number), .sub(sub), .eff_op(eff_op)); //instantiate FarPath component FarPath #( .size_in_mantissa(size_mantissa), .size_out_mantissa(size_mantissa), .size_exponent(size_exponent), .pipeline(pipeline), .pipeline_pos(pipeline_pos), .size_counter(size_counter), .double_size_in_mantissa(double_size_mantissa)) FarPath_instance ( .m_a_number(m_a_number), .m_b_number(m_b_number), .eff_op(eff_op), .exp_difference(exp_difference), .exp_inter(exp_inter), .resulted_m_o(fp_resulted_m_o), .resulted_e_o(fp_resulted_e_o)); //instantiate ClosePath component ClosePath #(.size_in_mantissa(size_mantissa), .size_out_mantissa(size_mantissa), .size_exponent(size_exponent), .pipeline(pipeline), .pipeline_pos(pipeline_pos), .size_counter(size_counter), .double_size_in_mantissa(double_size_mantissa)) ClosePath_instance( .m_a_number(m_a_number), .m_b_number(m_b_number), .exp_difference(exp_difference[0]), .exp_inter(exp_inter), .resulted_m_o(cp_resulted_m_o), .resulted_e_o(cp_resulted_e_o), .ovf(ovf)); //compute exception_field special_cases #( .size_exception_field(size_exception_field), .zero(zero), .normal_number(normal_number), .infinity(infinity), .NaN(NaN)) special_cases_instance( .sp_case_a_number(sp_case_a_number), .sp_case_b_number(sp_case_b_number), .sp_case_result_o(resulted_exception_field)); //set zero_flag in case of equal numbers assign zero_flag = (exp_difference > 1 | !eff_op)? ~((|{fp_resulted_m_o, resulted_exception_field[1]}) & (|resulted_exception_field)) : ~((|{cp_resulted_m_o, resulted_exception_field[1]}) & (|resulted_exception_field)); assign sign_cases = {eff_op, s_a_number, s_b_number, a_greater_exponent[size_exponent], b_greater_exponent[size_exponent]}; always @(*) begin case (sign_cases) 5'b00000: intermediar_sign = 1'b0; 5'b00001: intermediar_sign = 1'b0; 5'b00010: intermediar_sign = 1'b0; 5'b10000: intermediar_sign = ~ovf; 5'b10001: intermediar_sign = 1'b0; 5'b10010: intermediar_sign = 1'b1; 5'b10100: intermediar_sign = ~ovf; 5'b10101: intermediar_sign = 1'b0; 5'b10110: intermediar_sign = 1'b1; 5'b00100: intermediar_sign = 1'b0; 5'b00101: intermediar_sign = 1'b0; 5'b00110: intermediar_sign = 1'b0; 5'b11000: intermediar_sign = ovf; 5'b11001: intermediar_sign = 1'b1; 5'b11010: intermediar_sign = 1'b0; 5'b01000: intermediar_sign = 1'b1; 5'b01001: intermediar_sign = 1'b1; 5'b01010: intermediar_sign = 1'b1; 5'b01100: intermediar_sign = 1'b1; 5'b01101: intermediar_sign = 1'b1; 5'b01110: intermediar_sign = 1'b1; 5'b11100: intermediar_sign = ovf; 5'b11101: intermediar_sign = 1'b1; 5'b11110: intermediar_sign = 1'b0; default: intermediar_sign = 1'b1; endcase end assign resulted_sign = intermediar_sign; assign resulted_number_o = (zero_flag)? {size{1'b0}} : (!sp_case_a_number)? {b_number_i[size-1 : size-size_exception_field], eff_op ^ s_b_number, b_number_i[size-1-size_exception_field-1 : 0]} : (!sp_case_b_number)? {a_number_i[size-1 : 0]} : (exp_difference > 1 | !eff_op)? {resulted_exception_field, resulted_sign, fp_resulted_e_o, fp_resulted_m_o[size_mantissa-2 : 0]}: {resulted_exception_field, resulted_sign, cp_resulted_e_o, cp_resulted_m_o[size_mantissa-2 : 0]}; endmodule