jens
75f8ddd340
git-svn-id: http://moon:8086/svn/vhdl/trunk@171 cc03376c-175c-47c8-b038-4cd826a8556b
96 lines
2.1 KiB
VHDL
96 lines
2.1 KiB
VHDL
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library IEEE;
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use IEEE.STD_LOGIC_1164.ALL;
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use ieee.numeric_std.all;
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use IEEE.MATH_REAL.ALL;
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library ieee_proposed;
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use ieee_proposed.math_utility_pkg.all;
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use ieee_proposed.fixed_pkg.all;
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library work;
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use work.fixed_util_pkg.all;
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-------------------------------------------------------------------------------
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package nco_pkg is
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constant tpd : time := 0 ns;
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type real_array_t is array (natural range <>) of real;
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type natural_array_t is array (natural range <>) of natural;
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type phase_relation_t is (phase_90deg, phase_270deg);
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type debug_out_t is record
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lfsr : unsigned(31 downto 0);
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i_ud : real;
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q_ud : real;
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i_d : real;
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q_d : real;
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end record;
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constant lfsr_poly : natural_array_t(3 to 24) :=
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(
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12, -- 3
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24, -- 4
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58, -- 5
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114, -- 6
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210, -- 7
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500, -- 8
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1000, -- 9
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1824, -- 10
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3712, -- 11
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7184, -- 12
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14592, -- 13
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28674, -- 14
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59392, -- 15
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106512, -- 16
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245760, -- 17
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466944, -- 18
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933888, -- 19
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1654784, -- 20
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3735552, -- 21
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7342080, -- 22
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14745600, -- 23
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14811138 -- 24
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);
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function sin_tbl(nsamples : integer; omega, phi_in : real) return real_array_t;
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function cos_tbl(nsamples : integer; omega, phi_in : real) return real_array_t;
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end; -- package nco_pkg;
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-------------------------------------------------------------------------------
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package body nco_pkg is
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function sin_tbl(nsamples : integer; omega, phi_in : real) return real_array_t is
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variable tbl : real_array_t (0 to nsamples-1);
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variable phi : real := phi_in;
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variable dphi : real := 2.0*pi*omega;
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begin
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for i in 0 to nsamples-1 loop
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tbl(i) := sin(phi);
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phi := phi + dphi;
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end loop;
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return tbl;
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end sin_tbl;
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-------------------------------------------------------------
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function cos_tbl(nsamples : integer; omega, phi_in : real) return real_array_t is
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variable tbl : real_array_t (0 to nsamples-1);
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variable phi : real := phi_in;
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variable dphi : real := 2.0*pi*omega;
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begin
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for i in 0 to nsamples-1 loop
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tbl(i) := cos(phi);
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phi := phi + dphi;
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end loop;
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return tbl;
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end cos_tbl;
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-------------------------------------------------------------------------------
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end; -- package nco_pkg;
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