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constantin |
`timescale 1ns / 1ps
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//////////////////////////////////////////////////////////////////////////////////
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// Company:
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// Engineer:
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//
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// Create Date: 00:31:28 12/19/2013
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// Design Name:
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// Module Name: DualPathAdderConversion
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// Project Name:
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// Target Devices:
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// Tool versions:
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// Description: A ± B with mapped conversions
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//
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// Dependencies:
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//
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// Revision:
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// Revision 0.01 - File Created
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// Additional Comments:
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//
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//////////////////////////////////////////////////////////////////////////////////
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module DualPathAdderConversion #( parameter size_mantissa = 24, //1.M
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parameter size_exponent = 8,
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parameter size_exception_field = 2,
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parameter size_counter = 5,//log2(size_mantissa) + 1 = 5)
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parameter [size_exception_field - 1 : 0] zero = 0, //00
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parameter [size_exception_field - 1 : 0] normal_number = 1, //01
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parameter [size_exception_field - 1 : 0] infinity = 2, //10
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parameter [size_exception_field - 1 : 0] NaN = 3, //11
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parameter size_integer = 32,
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parameter counter_integer = 6,//log2(size_integer) + 1 = 6)
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parameter [1 : 0] FP_operation = 0, //00
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parameter [1 : 0] FP_to_int = 1, //01 - mapped on FarPath
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parameter [1 : 0] int_to_FP = 2, //10 - mapped on ClosePath
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parameter pipeline = 0,
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parameter pipeline_pos = 0, // 8 bits
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parameter size = size_mantissa + size_exponent + size_exception_field
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)
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( input [1:0] conversion,
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input sub,
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input [size - 1 : 0] a_number_i,
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input [size - 1 : 0] b_number_i,
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output[size - 1 : 0] resulted_number_o);
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parameter double_size_mantissa = size_mantissa + size_mantissa;
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parameter double_size_counter = size_counter + 1;
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parameter max_size = (size_integer > size_mantissa)? size_integer : size_mantissa;
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parameter max_counter = (counter_integer > size_counter)? counter_integer : size_counter;
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parameter size_diff_i_m = (size_integer > size_mantissa)? (size_integer - size_mantissa) : (size_mantissa - size_integer);
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parameter bias = {1'b0,{(size_exponent-1){1'b1}}};
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parameter exp_biasedCP = bias + size_mantissa;
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parameter exponentCP = exp_biasedCP - 1'b1;
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wire [size_exception_field - 1 : 0] sp_case_a_number, sp_case_b_number;
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wire [size_mantissa - 1 : 0] m_a_number, m_b_number;
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wire [size_exponent - 1 : 0] e_a_number, e_b_number;
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wire s_a_number, s_b_number;
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wire [size_exponent : 0] a_greater_exponent, b_greater_exponent;
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wire [size_exponent - 1 : 0] exp_difference;
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wire [size_exponent : 0] exp_inter;
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wire eff_op;
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17 |
constantin |
wire [size_exception_field - 1 : 0] sp_case_o, resulted_exception_field;
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11 |
constantin |
wire resulted_sign;
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wire swap;
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wire zero_flag;
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wire [max_size - 1 : 0] max_entityFP;
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wire [size_exponent - 1 : 0] resulted_e_oFP;
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wire [size_exponent - 1 : 0] adjust_mantissaFP;
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wire [size_exponent - 1 : 0] unadjusted_exponentFP;
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wire [size_mantissa - 1 : 0] mantissa_to_shiftFP, shifted_m_bFP, convert_neg_mantissaFP;
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wire [size_mantissa + 1 : 0] adder_mantissaFP;
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wire [size_mantissa - 1 : 0] resulted_inter_m_oFP, resulted_m_oFP;
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wire [size_mantissa - 1 : 0] initial_rounding_bitsFP, inter_rounding_bitsFP;
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wire [double_size_mantissa:0] normalized_mantissaFP;
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wire [size_mantissa : 0] unnormalized_mantissaFP, conversion_dummiesFP;
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wire [size_exponent : 0] shift_value_when_positive_exponentFP, shift_value_when_negative_exponentFP;
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wire [size_exponent - 1 : 0] shift_valueFP, shft_valFP;
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wire [size_exponent : 0] exponentFP;
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wire dummy_bitFP;
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wire [max_size - 1 : 0] max_entityCP;
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wire [size_mantissa - 1 : 0] shifted_m_bCP;
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wire [size_mantissa + 1 : 0] adder_mantissaCP;
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wire [size_mantissa : 0] unnormalized_mantissaCP;
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wire [size_mantissa : 0] rounded_mantissaCP;
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wire [size_mantissa - 1 : 0] r_mantissaCP;
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wire [size_exponent - 1 : 0] resulted_e_oCP;
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wire [size_mantissa - 1 : 0] resulted_m_oCP;
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wire [size_exponent - 1 : 0] unadjusted_exponentCP, adjust_exponentCP;
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wire [size_exponent - 1 : 0] exp_selectionCP;
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wire [max_size - size_mantissa : 0] dummy_bitsCP;
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wire [max_counter - 1 : 0] lzsCP;
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wire init_shft_bitCP, shft_bitCP;
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wire lsb_shft_bitCP;
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wire do_conversion;
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assign do_conversion = |conversion; //let me know if there is a conversion
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assign e_a_number = a_number_i[size_mantissa + size_exponent - 1 : size_mantissa - 1]; //exponent for a_number_i
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assign e_b_number = b_number_i[size_mantissa + size_exponent - 1 : size_mantissa - 1]; //exponent for b_number_i
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assign s_a_number = a_number_i[size - size_exception_field - 1]; //sign for a_number_i
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assign s_b_number = b_number_i[size - size_exception_field - 1]; //sign for b_number_i
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assign sp_case_a_number = a_number_i[size - 1 : size - size_exception_field]; //special_case for a_number_i
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assign sp_case_b_number = b_number_i[size - 1 : size - size_exception_field]; //special_case for b_number_i
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//find the greater exponent
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assign a_greater_exponent = e_a_number - e_b_number;
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assign b_greater_exponent = e_b_number - e_a_number;
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//find the difference between exponents
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assign exp_difference = (a_greater_exponent[size_exponent])? b_greater_exponent[size_exponent - 1 : 0] : a_greater_exponent[size_exponent - 1 : 0];
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assign exp_inter = (b_greater_exponent[size_exponent])? {1'b0, e_a_number} : {1'b0, e_b_number};
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//set shifter always on m_b_number
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assign {swap, m_a_number, m_b_number} = do_conversion? {1'b0,{e_a_number[0], a_number_i[size_mantissa - 2 :0]}, {1'b1, b_number_i[size_mantissa - 2 :0]}} :
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(b_greater_exponent[size_exponent])?
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{1'b0, {1'b1, a_number_i[size_mantissa - 2 :0]}, {1'b1, b_number_i[size_mantissa - 2 :0]}} :
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{1'b1, {1'b1, b_number_i[size_mantissa - 2 :0]}, {1'b1, a_number_i[size_mantissa - 2 :0]}};
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effective_op effective_op_instance( .a_sign(s_a_number), .b_sign(s_b_number), .sub(sub), .eff_op(eff_op));
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//------------------------------------------------------- start ClosePath addition and conversion
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assign {shifted_m_bCP, init_shft_bit} = (exp_difference)? {1'b0, m_b_number[size_mantissa-1:0]} : {m_b_number, 1'b0};
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//compute unnormalized_mantissa
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assign adder_mantissaCP = {1'b0, m_a_number} - shifted_m_bCP;
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assign {unnormalized_mantissaCP, shft_bitCP} =
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(adder_mantissaCP[size_mantissa + 1])? ({~adder_mantissaCP[size_mantissa : 0], ~init_shft_bitCP}) :
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({adder_mantissaCP[size_mantissa : 0], init_shft_bitCP});
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assign max_entityCP = do_conversion? (s_a_number? (~a_number_i[max_size-1 : 0]) : a_number_i[max_size-1 : 0]) :
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{{(max_size-size_mantissa-1){1'b0}}, unnormalized_mantissaCP[size_mantissa : 0]};
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assign lsb_shft_bitCP = (do_conversion)? s_a_number : max_entityCP[0];
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assign max_ovfCP = do_conversion? 1'b0 : unnormalized_mantissaCP[size_mantissa];
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//compute leading_zeros over unnormalized mantissa
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leading_zeros #(.SIZE_INT(max_size), .SIZE_COUNTER(max_counter), .PIPELINE(pipeline))
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leading_zeros_CP_instance ( .a(max_entityCP),
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.ovf(max_ovfCP),
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.lz(lzsCP));
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//compute shifting over unnormalized_mantissa
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shifter #( .INPUT_SIZE(max_size),
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.SHIFT_SIZE(max_counter),
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.OUTPUT_SIZE(max_size + 1),
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.DIRECTION(1'b1), //0=right, 1=left
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.PIPELINE(pipeline),
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.POSITION(pipeline_pos))
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shifter_CP_instance( .a(max_entityCP),//mantissa
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.arith(lsb_shft_bitCP),
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.shft(lzsCP),
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.shifted_a({r_mantissaCP, dummy_bitsCP}));
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assign rounded_mantissaCP = (r_mantissaCP[0] && dummy_bitsCP[max_size - size_mantissa] && (|dummy_bitsCP[max_size - size_mantissa - 1 : 0 ]))?
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r_mantissaCP + 1'b1 : r_mantissaCP;
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assign resulted_m_oCP = (rounded_mantissaCP[size_mantissa])? rounded_mantissaCP[size_mantissa : 1] :
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rounded_mantissaCP[size_mantissa-1:0];
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assign ovfCP = do_conversion? s_a_number : adder_mantissaCP[size_mantissa+1];
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assign exp_selectionCP = do_conversion? exponentCP : exp_inter;
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assign adjust_exponentCP = exp_selectionCP - lzsCP;
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assign unadjusted_exponentCP = adjust_exponentCP + size_diff_i_m;
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assign resulted_e_oCP = (do_conversion & ~(|max_entityCP))? bias : unadjusted_exponentCP + rounded_mantissaCP[size_mantissa];
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//------------------------------------------------------- end ClosePath addition and conversion
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//--------------------------------------------- start FarPath addition and conversion
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assign exponentFP = e_a_number - bias;
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assign shift_value_when_positive_exponentFP = max_size - 2'd2 - exponentFP[size_exponent-1 : 0];
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assign shift_value_when_negative_exponentFP = max_size + (~exponentFP[size_exponent-1 : 0]);
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assign shift_valueFP = (exponentFP[size_exponent])? shift_value_when_negative_exponentFP[size_exponent - 1 : 0] :
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(shift_value_when_positive_exponentFP[size_exponent])? (~shift_value_when_positive_exponentFP[size_exponent - 1 : 0]):
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shift_value_when_positive_exponentFP[size_exponent - 1 : 0];
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assign shft_valFP = do_conversion? shift_valueFP : exp_difference;
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assign convert_neg_mantissaFP = {1'b0, ~a_number_i[size_mantissa-2 : 0]};
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assign conversion_dummiesFP = {(size_mantissa+1){1'b1}};
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assign mantissa_to_shiftFP = do_conversion? (s_a_number? convert_neg_mantissaFP + 1'b1 : {1'b1, a_number_i[size_mantissa-2 : 0]}) : m_b_number;
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assign arith_shiftFP = do_conversion? s_a_number : 1'b0;
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//shift m_b_number
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shifter #( .INPUT_SIZE(size_mantissa),
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.SHIFT_SIZE(size_exponent),
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.OUTPUT_SIZE(double_size_mantissa),
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.DIRECTION(1'b0), //0=right, 1=left
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.PIPELINE(pipeline),
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.POSITION(pipeline_pos))
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m_b_shifter_FP_instance( .a(mantissa_to_shiftFP),
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.arith(arith_shiftFP),
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.shft(shft_valFP),
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.shifted_a({shifted_m_bFP, initial_rounding_bitsFP}));
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assign max_entityFP = {s_a_number, shifted_m_bFP[size_mantissa-1 : 0], initial_rounding_bitsFP[size_mantissa-1 : size_mantissa - size_diff_i_m + 1]};
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//compute unnormalized_mantissa
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assign adder_mantissaFP = (eff_op)? ({1'b0, m_a_number} - {1'b0, shifted_m_bFP}) : ({1'b0, m_a_number} + {1'b0, shifted_m_bFP});
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assign {unnormalized_mantissaFP, inter_rounding_bitsFP} =
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(adder_mantissaFP[size_mantissa + 1])? ({~adder_mantissaFP[size_mantissa : 0], ~initial_rounding_bitsFP}) :
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({adder_mantissaFP[size_mantissa : 0], initial_rounding_bitsFP});
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assign adjust_mantissaFP = unnormalized_mantissaFP[size_mantissa]? 2'd0 :
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unnormalized_mantissaFP[size_mantissa-1]? 2'd1 : 2'd2;
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//compute shifting over unnormalized_mantissa
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shifter #( .INPUT_SIZE(double_size_mantissa+1),
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.SHIFT_SIZE(size_exponent),
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.OUTPUT_SIZE(double_size_mantissa+2),
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.DIRECTION(1'b1),
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.PIPELINE(pipeline),
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.POSITION(pipeline_pos))
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unnormalized_no_shifter_FP_instance(.a({unnormalized_mantissaFP, inter_rounding_bitsFP}),
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.arith(1'b0),
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.shft(adjust_mantissaFP),
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.shifted_a({normalized_mantissaFP, dummy_bitFP}));
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//instantiate rounding_component
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rounding #( .SIZE_MOST_S_MANTISSA(size_mantissa),
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.SIZE_LEAST_S_MANTISSA(size_mantissa + 2'd1))
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rounding_FP_instance( .unrounded_mantissa(normalized_mantissaFP[double_size_mantissa : double_size_mantissa - size_mantissa + 1]),
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.dummy_bits(normalized_mantissaFP[double_size_mantissa - size_mantissa: 0]),
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.rounded_mantissa(resulted_inter_m_oFP));
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assign resulted_m_oFP = do_conversion? max_entityFP[size_mantissa-1 : 0] : resulted_inter_m_oFP;
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assign unadjusted_exponentFP = exp_inter - adjust_mantissaFP;
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assign resulted_e_oFP = do_conversion? max_entityFP[size_mantissa+size_exponent-2 : size_mantissa-1] : unadjusted_exponentFP + 1'b1;
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//-------------------------------------------------------- end FarPath addition and conversion
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//compute exception_field
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special_cases #( .size_exception_field(size_exception_field),
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.zero(zero),
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.normal_number(normal_number),
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.infinity(infinity),
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.NaN(NaN))
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special_cases_instance( .sp_case_a_number(sp_case_a_number),
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17 |
constantin |
.sp_case_b_number(sp_case_b_number),
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.sp_case_result_o(sp_case_o));
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assign resulted_exception_field = do_conversion? sp_case_a_number : sp_case_o;
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253 |
11 |
constantin |
//set zero_flag in case of equal numbers
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17 |
constantin |
assign zero_flag = ((exp_difference > 1 | !eff_op) & conversion != int_to_FP)?
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~((|{resulted_m_oFP, sp_case_o[1]}) & (|sp_case_o)) :
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~((|{resulted_m_oCP, sp_case_o[1]}) & (|sp_case_o));
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257 |
11 |
constantin |
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assign resulted_sign = do_conversion? s_a_number :
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((exp_difference > 1 | !eff_op)? (!a_greater_exponent[size_exponent]? s_a_number : (eff_op? ~s_b_number : s_b_number)) :
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(ovfCP ^ swap));
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assign resulted_number_o = (zero_flag)? {size{1'b0}} : ((exp_difference > 1 | !eff_op) & conversion != int_to_FP)?
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{resulted_exception_field, resulted_sign, resulted_e_oFP, resulted_m_oFP[size_mantissa-2 : 0]}:
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{resulted_exception_field, resulted_sign, resulted_e_oCP, resulted_m_oCP[size_mantissa-2 : 0]};
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endmodule
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