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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: 00:32:10 11/19/2013
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// Create Date: 00:32:10 11/19/2013
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// Design Name:
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// Design Name:
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// Module Name: ClosePath
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// Module Name: ClosePath
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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: leading_zeros.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 [1 : 0] adjust_exponent;
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wire [1 : 0] adjust_exponent;
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wire [2 : 0] dummy_bits;
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wire [2 : 0] dummy_bits;
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wire init_shft_bit, shft_bit;
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wire init_shft_bit, shft_bit;
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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 : 0] rounded_mantissa;
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wire [size_in_mantissa : 0] rounded_mantissa;
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wire [size_in_mantissa-1: 0] r_mantissa;
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wire [size_in_mantissa-1: 0] r_mantissa;
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wire [size_in_mantissa : 0] aux_r_mantissa;
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assign {shifted_m_b, init_shft_bit} = (exp_difference)? {1'b0, m_b_number[size_in_mantissa-1:0]} : {m_b_number, 1'b0};
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assign {shifted_m_b, init_shft_bit} = (exp_difference)? {1'b0, m_b_number[size_in_mantissa-1:0]} : {m_b_number, 1'b0};
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//compute unnormalized_mantissa
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//compute unnormalized_mantissa
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assign adder_mantissa = {1'b0, m_a_number} - {1'b0, shifted_m_b};
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assign adder_mantissa = {1'b0, m_a_number, 1'b0} - {1'b0, shifted_m_b, init_shft_bit};
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assign unnormalized_mantissa = adder_mantissa[size_in_mantissa + 1]? ~adder_mantissa : adder_mantissa;
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assign {unnormalized_mantissa, shft_bit} =
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(adder_mantissa[size_in_mantissa + 1])? ({~adder_mantissa[size_in_mantissa : 0], ~init_shft_bit}) :
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({adder_mantissa[size_in_mantissa : 0], init_shft_bit});
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//compute leading_zeros over unnormalized mantissa
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//compute leading_zeros over unnormalized mantissa
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leading_zeros #( .SIZE_INT(size_in_mantissa + 1), .SIZE_COUNTER(size_counter), .PIPELINE(pipeline))
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leading_zeros #( .SIZE_INT(size_in_mantissa + 2), .SIZE_COUNTER(size_counter), .PIPELINE(pipeline))
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leading_zeros_instance (.a(unnormalized_mantissa[size_in_mantissa : 0]),
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leading_zeros_instance (.a(unnormalized_mantissa[size_in_mantissa+1 : 0]),
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.ovf(unnormalized_mantissa[size_in_mantissa]),
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.ovf(unnormalized_mantissa[size_in_mantissa+1]),
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.lz(lzs));
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.lz(lzs));
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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(size_in_mantissa + 2),
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shifter #( .INPUT_SIZE(size_in_mantissa + 2),
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.SHIFT_SIZE(size_counter),
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.SHIFT_SIZE(size_counter),
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.OUTPUT_SIZE(size_in_mantissa + 3),
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.OUTPUT_SIZE(size_in_mantissa + 3),
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.DIRECTION(1'b1), //0=right, 1=left
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.DIRECTION(1'b1), //0=right, 1=left
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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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shifter_instance( .a({unnormalized_mantissa, shft_bit}),//mantissa
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shifter_instance( .a({unnormalized_mantissa}),//mantissa
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.arith(adder_mantissa[size_in_mantissa + 1]),//logical shift
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.arith(adder_mantissa[size_in_mantissa+2]),//logical shift
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.shft(lzs),
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.shft(lzs),
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.shifted_a({r_mantissa, dummy_bits}));
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.shifted_a({r_mantissa, dummy_bits}));
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assign rounded_mantissa = (adder_mantissa[size_in_mantissa + 1])? {1'b0, r_mantissa} + 1'b1 : {1'b0, r_mantissa};
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//assign aux_r_mantissa = {1'b0, r_mantissa} + 1'b1;
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assign rounded_mantissa = (r_mantissa[0] & (dummy_bits[2]))? {1'b0, r_mantissa} + 1'b1 : {1'b0, r_mantissa};
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assign resulted_m_o = (rounded_mantissa[size_in_mantissa])? rounded_mantissa[size_in_mantissa : 1] :
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assign resulted_m_o = (rounded_mantissa[size_in_mantissa])? rounded_mantissa[size_in_mantissa : 1] :
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rounded_mantissa[size_in_mantissa-1:0];
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rounded_mantissa[size_in_mantissa-1:0];
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assign adjust_exponent = rounded_mantissa[size_in_mantissa]? 2'd2 : 2'd1;
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assign adjust_exponent = rounded_mantissa[size_in_mantissa]? 2'd2 : 2'd1;
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