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`timescale 1ns / 1ps
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`timescale 1ns / 1ps
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//////////////////////////////////////////////////////////////////////////////////
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//////////////////////////////////////////////////////////////////////////////////
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// Company:
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// Company: UPT
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// Engineer:
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// Engineer: Constantina-Elena Gavriliu
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//
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//
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// Create Date: 00:31:57 11/19/2013
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// Create Date: 00:31:57 11/19/2013
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// Design Name:
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// Design Name:
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// Module Name: FarPath
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// Module Name: FarPath
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// Project Name:
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// Project Name:
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// Target Devices:
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// Target Devices:
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// Tool versions:
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// Tool versions:
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// Description: A ± B when |Ea-Eb| >= 2
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// Description: A ± B when |Ea-Eb| >= 2
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//
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//
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// Dependencies:
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// Dependencies: rounding.v
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// shifter.v
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//
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//
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// Revision:
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// Revision:
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// Revision 0.01 - File Created
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// Revision 0.01 - File Created
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// Additional Comments:
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// Additional Comments:
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//
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//
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wire [size_exponent- 1 : 0] adjust_mantissa;
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wire [size_exponent- 1 : 0] adjust_mantissa;
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wire [size_exponent- 1 : 0] unadjusted_exponent;
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wire [size_exponent- 1 : 0] unadjusted_exponent;
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wire [double_size_in_mantissa:0] normalized_mantissa;
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wire [double_size_in_mantissa:0] normalized_mantissa;
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wire [size_in_mantissa-1: 0] shifted_m_b;
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wire [size_in_mantissa-1: 0] shifted_m_b;
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wire [size_in_mantissa+1: 0] adder_mantissa;
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wire [size_in_mantissa + 2 : 0] adder_mantissa;
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wire [size_in_mantissa : 0] unnormalized_mantissa;
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wire [size_in_mantissa + 1 : 0] unnormalized_mantissa;
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wire [size_in_mantissa - 1 : 0] initial_rounding_bits, inter_rounding_bits;
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wire [size_in_mantissa - 1 : 0] initial_rounding_bits;
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wire [size_in_mantissa - 2 : 0] inter_rounding_bits;
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wire dummy_bit;
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wire dummy_bit;
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wire dummy_ovf, negation_cond, correction;
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//shift m_b_number
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//shift m_b_number
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shifter #( .INPUT_SIZE(size_in_mantissa),
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shifter #( .INPUT_SIZE(size_in_mantissa),
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.SHIFT_SIZE(size_exponent),
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.SHIFT_SIZE(size_exponent),
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.OUTPUT_SIZE(double_size_in_mantissa),
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.OUTPUT_SIZE(double_size_in_mantissa),
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m_b_shifter_instance( .a(m_b_number),//mantissa
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m_b_shifter_instance( .a(m_b_number),//mantissa
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.arith(1'b0),//logical shift
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.arith(1'b0),//logical shift
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.shft(exp_difference),
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.shft(exp_difference),
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.shifted_a({shifted_m_b, initial_rounding_bits}));
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.shifted_a({shifted_m_b, initial_rounding_bits}));
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//compute addition
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assign adder_mantissa = (eff_op)? ({1'b0, m_a_number, 1'b0} - {1'b0, shifted_m_b, initial_rounding_bits[size_in_mantissa - 1]}) :
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({1'b0, m_a_number, 1'b0} + {1'b0, shifted_m_b, initial_rounding_bits[size_in_mantissa - 1]});
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//compute unnormalized_mantissa
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//compute unnormalized_mantissa
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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});
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assign unnormalized_mantissa = (adder_mantissa[size_in_mantissa + 2])? ~adder_mantissa[size_in_mantissa + 1 : 0] : adder_mantissa[size_in_mantissa + 1 : 0];
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assign {unnormalized_mantissa, inter_rounding_bits} =
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assign inter_rounding_bits = ((eff_op)? ((|initial_rounding_bits[size_in_mantissa - 2 : 0])?~initial_rounding_bits[size_in_mantissa - 2 : 0] : initial_rounding_bits[size_in_mantissa - 2 : 0]) : initial_rounding_bits[size_in_mantissa - 2 : 0]);
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(adder_mantissa[size_in_mantissa + 1])? ({~adder_mantissa[size_in_mantissa : 0], ~initial_rounding_bits}) :
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({adder_mantissa[size_in_mantissa : 0], initial_rounding_bits});
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assign adjust_mantissa = unnormalized_mantissa[size_in_mantissa]? 2'd0 :
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unnormalized_mantissa[size_in_mantissa-1]? 2'd1 : 2'd2;
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assign adjust_mantissa = unnormalized_mantissa[size_in_mantissa + 1]? 2'd0 :
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unnormalized_mantissa[size_in_mantissa]? 2'd1 : 2'd2;
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//compute shifting over unnormalized_mantissa
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//compute shifting over unnormalized_mantissa
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shifter #( .INPUT_SIZE(double_size_in_mantissa+1),
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shifter #( .INPUT_SIZE(double_size_in_mantissa+1),
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.SHIFT_SIZE(size_exponent),
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.SHIFT_SIZE(size_exponent),
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.OUTPUT_SIZE(double_size_in_mantissa+2),
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.OUTPUT_SIZE(double_size_in_mantissa+2),
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.DIRECTION(1'b1),
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.DIRECTION(1'b1),
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.PIPELINE(pipeline),
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.PIPELINE(pipeline),
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.POSITION(pipeline_pos))
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.POSITION(pipeline_pos))
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unnormalized_no_shifter_instance(.a({unnormalized_mantissa, inter_rounding_bits}),
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unnormalized_no_shifter_instance(.a({unnormalized_mantissa, inter_rounding_bits}),
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.arith(1'b0),
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.arith(inter_rounding_bits[0]),
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.shft(adjust_mantissa),
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.shft(adjust_mantissa),
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.shifted_a({normalized_mantissa, dummy_bit}));
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.shifted_a({normalized_mantissa, dummy_bit}));
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assign correction = eff_op? ((|initial_rounding_bits[size_in_mantissa - 2 : 0])?
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((adder_mantissa[0] | ((~adder_mantissa[0]) & (~adder_mantissa[size_in_mantissa]) & (~initial_rounding_bits[size_in_mantissa - 1])
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& (~(&{normalized_mantissa[size_in_mantissa-1 : 0],dummy_bit}))))? 1'b1 : 1'b0) : 1'b0) : 1'b0;
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//instantiate rounding_component
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//instantiate rounding_component
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rounding #( .SIZE_MOST_S_MANTISSA(size_out_mantissa),
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rounding #( .SIZE_MOST_S_MANTISSA(size_out_mantissa),
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.SIZE_LEAST_S_MANTISSA(size_out_mantissa + 2'd1))
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.SIZE_LEAST_S_MANTISSA(size_out_mantissa + 2'd1))
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rounding_instance( .unrounded_mantissa(normalized_mantissa[double_size_in_mantissa : double_size_in_mantissa - size_out_mantissa + 1]),
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rounding_instance( .unrounded_mantissa(normalized_mantissa[double_size_in_mantissa : double_size_in_mantissa - size_out_mantissa + 1]),
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.dummy_bits(normalized_mantissa[double_size_in_mantissa - size_out_mantissa: 0]),
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.dummy_bits(normalized_mantissa[double_size_in_mantissa - size_out_mantissa: 0]),
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.correction(correction),
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.rounded_mantissa(resulted_m_o));
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.rounded_mantissa(resulted_m_o));
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assign unadjusted_exponent = exp_inter - adjust_mantissa;
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assign unadjusted_exponent = exp_inter - adjust_mantissa;
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assign resulted_e_o = unadjusted_exponent + 1'b1;
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assign resulted_e_o = unadjusted_exponent + 1'b1;
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