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[/] [xilinx_virtex_fp_library/] [trunk/] [SinglePathFPAdderMappedConversions/] [SinglePathAdderConversion.v] - Rev 17
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`timescale 1ns / 1ps ////////////////////////////////////////////////////////////////////////////////// // Company: // Engineer: // // Create Date: 16:09:49 11/04/2013 // Design Name: // Module Name: SinglePathAdderConversion // Project Name: // Target Devices: // Tool versions: // Description: A ± B with mapped conversions // // Dependencies: // // Revision: // Revision 0.01 - File Created // Additional Comments: // ////////////////////////////////////////////////////////////////////////////////// module SinglePathAdderConversion #( parameter size_mantissa = 24, //calculate the size containing the hiden bit 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 size_integer = 32, parameter counter_integer = 6,//log2(size_integer) + 1 = 6) parameter [1 : 0] FP_operation = 0, //00 parameter [1 : 0] FP_to_int = 1, //01 parameter [1 : 0] int_to_FP = 2, //10 parameter pipeline = 0, parameter pipeline_pos = 0, // 8 bits parameter size = size_mantissa + size_exponent + size_exception_field ) ( input [1:0] conversion, input sub, input [size - 1 : 0] a_number_i, input [size - 1 : 0] b_number_i, output[size - 1 : 0] resulted_number_o); parameter double_size_mantissa = size_mantissa + size_mantissa; parameter double_size_counter = size_counter + 1; parameter max_size = (size_integer > size_mantissa)? size_integer : size_mantissa; parameter max_counter = (counter_integer > size_counter)? counter_integer : size_counter; parameter size_diff_i_m = (size_integer > size_mantissa)? (size_integer - size_mantissa) : (size_mantissa - size_integer); parameter bias = {1'b0,{(size_exponent-1){1'b1}}}; parameter exp_biased = bias + size_mantissa; parameter exponent = exp_biased - 1'b1; parameter subtr = max_size -2'd2; 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, convert_neg_mantissa, mantissa_to_shift; wire [size_mantissa - 1 : 0] initial_rounding_bits, inter_rounding_bits; wire eff_op; wire [size_mantissa + 1 : 0] adder_mantissa; wire [size_mantissa : 0] unnormalized_mantissa; wire [size_exception_field - 1 : 0] sp_case_o, resulted_exception_field; wire [size_mantissa - 1 : 0] resulted_mantissa; wire [size_exponent - 1 : 0] resulted_exponent; wire resulted_sign; wire zero_flag; wire [size_exponent : 0] subtracter; wire [max_size - size_mantissa : 0] dummy_bits; wire [size_exponent : 0] shift_value_when_positive_exponent, shift_value_when_negative_exponent; wire [size_exponent - 1 : 0] shift_value, shft_val; wire lsb_shft_bit; wire [size_exponent - 1 : 0] max_resulted_e_o; wire [size_exponent - 1 : 0] max_unadjusted_exponent, max_adjust_exponent; wire [size_exponent - 1 : 0] max_exp_selection; wire [size_mantissa - 1 : 0] r_mantissa; wire [size_mantissa : 0] max_rounded_mantissa; wire [max_counter - 1 : 0] max_lzs; wire [max_size - 1 : 0] max_entityINT_FP, max_entityFP_INT; wire arith_shift; wire max_ovf; wire do_conversion; assign do_conversion = |conversion; //let me know if there is a conversion 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]}}; assign subtracter = e_a_number - bias; assign shift_value_when_positive_exponent = subtr - subtracter[size_exponent-1 : 0]; assign shift_value_when_negative_exponent = max_size + (~subtracter[size_exponent-1 : 0]); assign shift_value = (subtracter[size_exponent])? shift_value_when_negative_exponent[size_exponent - 1 : 0] : (shift_value_when_positive_exponent[size_exponent])? (~shift_value_when_positive_exponent[size_exponent - 1 : 0]): shift_value_when_positive_exponent[size_exponent - 1 : 0]; assign shft_val = do_conversion? shift_value : exp_difference; assign convert_neg_mantissa = {1'b0, ~a_number_i[size_mantissa-2 : 0]}; assign mantissa_to_shift = conversion[0]? (s_a_number? convert_neg_mantissa + 1'b1 : {1'b1, a_number_i[size_mantissa-2 : 0]}) : m_b_number; assign arith_shift = conversion[0]? s_a_number : 1'b0; //shift m_b_number shifter #( .INPUT_SIZE(size_mantissa), .SHIFT_SIZE(size_exponent), .OUTPUT_SIZE(double_size_mantissa), .DIRECTION(1'b0), //0=right, 1=left .PIPELINE(pipeline), .POSITION(pipeline_pos)) m_b_shifter_instance( .a(mantissa_to_shift),//mantissa .arith(arith_shift),//logical shift .shft(shft_val), .shifted_a({shifted_m_b, initial_rounding_bits})); assign max_entityFP_INT = {s_a_number, shifted_m_b[size_mantissa-1 : 0], initial_rounding_bits[size_mantissa-1 : size_mantissa - size_diff_i_m + 1]}; //istantiate effective_operation_component effective_op effective_op_instance( .a_sign(s_a_number), .b_sign(s_b_number), .sub(sub), .eff_op(eff_op)); //compute unnormalized_mantissa assign adder_mantissa = (eff_op)? ({1'b0, m_a_number} - {1'b0, shifted_m_b}) : ({1'b0, m_a_number} + {1'b0, shifted_m_b}); assign {unnormalized_mantissa, inter_rounding_bits} = (adder_mantissa[size_mantissa + 1])? ({~adder_mantissa[size_mantissa : 0], ~initial_rounding_bits}) : ({adder_mantissa[size_mantissa : 0], initial_rounding_bits}); assign max_entityINT_FP = do_conversion? (s_a_number? (~a_number_i[max_size-1 : 0]) : a_number_i[max_size-1 : 0]) : {{(max_size-size_mantissa-1){1'b0}}, unnormalized_mantissa[size_mantissa : 0]}; assign lsb_shft_bit = (do_conversion)? s_a_number : max_entityINT_FP[0]; assign max_ovf = do_conversion? 1'b0 : unnormalized_mantissa[size_mantissa]; //compute leading_zeros over unnormalized mantissa leading_zeros #( .SIZE_INT(max_size), .SIZE_COUNTER(max_counter), .PIPELINE(pipeline)) leading_zeros_instance (.a(max_entityINT_FP), .ovf(max_ovf), .lz(max_lzs)); //compute shifting over unnormalized_mantissa shifter #( .INPUT_SIZE(max_size), .SHIFT_SIZE(max_counter), .OUTPUT_SIZE(max_size + 1), .DIRECTION(1'b1), //0=right, 1=left .PIPELINE(pipeline), .POSITION(pipeline_pos)) shifter_instance( .a(max_entityINT_FP),//mantissa .arith(lsb_shft_bit),//logical shift .shft(max_lzs), .shifted_a({r_mantissa, dummy_bits})); //instantiate rounding_component rounding #( .SIZE_MOST_S_MANTISSA(size_mantissa + 1), .SIZE_LEAST_S_MANTISSA(max_size - size_mantissa + 1)) rounding_instance( .unrounded_mantissa({1'b0,r_mantissa}), .dummy_bits(dummy_bits), .rounded_mantissa(max_rounded_mantissa)); assign max_exp_selection = do_conversion? exponent : exp_inter; assign max_adjust_exponent = max_exp_selection - max_lzs; assign max_unadjusted_exponent = max_adjust_exponent + size_diff_i_m; assign max_resulted_e_o = (do_conversion & ~(|max_entityINT_FP))? bias : max_unadjusted_exponent + max_rounded_mantissa[size_mantissa]; assign resulted_exponent = conversion[0]? max_entityFP_INT[size_mantissa+size_exponent-2 : size_mantissa-1] : max_resulted_e_o; assign resulted_mantissa = conversion[0]? max_entityFP_INT[size_mantissa-1 : 0] : (max_rounded_mantissa[size_mantissa])? (max_rounded_mantissa[size_mantissa : 1]) : (max_rounded_mantissa[size_mantissa-1 : 0]); //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(sp_case_o)); //compute special case assign resulted_exception_field = do_conversion? sp_case_a_number : sp_case_o; //set zero_flag in case of equal numbers assign zero_flag = ~((|{resulted_mantissa,sp_case_o[1]}) & (|sp_case_o)); //compute resulted_sign assign resulted_sign = do_conversion? s_a_number : ((eff_op)? (!a_greater_exponent[size_exponent]? (!b_greater_exponent[size_exponent]? ~adder_mantissa[size_mantissa+1] : s_a_number) : ~s_b_number) : s_a_number); assign resulted_number_o = (zero_flag)? {size{1'b0}} : {resulted_exception_field, resulted_sign, resulted_exponent, resulted_mantissa[size_mantissa - 2 : 0]}; endmodule
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