Initial import

git-svn-id: http://moon:8086/svn/vhdl/trunk@5 cc03376c-175c-47c8-b038-4cd826a8556b
2008-08-23 08:20:30 +00:00
parent bfbeba5129
commit d3bd08bb52
160 changed files with 56260 additions and 0 deletions
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+
+library IEEE;
+use IEEE.STD_LOGIC_1164.ALL;
+use ieee.numeric_std.all;
+use IEEE.MATH_REAL.ALL;
+use work.fixed_pkg.all;
+
+-------------------------------------------------------------------------------
+package nco_pkg is
+
+	constant tpd : time := 0 ns;
+
+	-- Global set arithmetic rounding mode
+	constant pi			: real := 3.141592653589793e+000;
+	constant sqrt2		: real := 1.414213562373095e+000;
+	constant sqrt2_inv	: real := 7.071067811865475e-001;
+
+	type real_array_t is array (natural range <>) of real;
+	type natural_array_t is array (natural range <>) of natural;
+	type phase_relation_t is (phase_90deg, phase_270deg);
+	
+	type debug_out_t is record 
+		lfsr : unsigned(31 downto 0);
+		i_ud : real;
+		q_ud : real;
+		i_d : real;
+		q_d : real;
+	end record;
+
+	constant lfsr_poly : natural_array_t(3 to 24) := 
+	(
+		12,			-- 3
+		24,			-- 4
+		58,			-- 5
+		114,		-- 6
+		210,		-- 7
+		500,		-- 8
+		1000,		-- 9
+		1824,		-- 10
+		3712,		-- 11
+		7184,		-- 12
+		14592,		-- 13
+		28674,		-- 14
+		59392,		-- 15
+		106512,		-- 16
+		245760,		-- 17
+		466944,		-- 18
+		933888,		-- 19
+		1654784,	-- 20
+		3735552,	-- 21
+		7342080,	-- 22
+		14745600,	-- 23
+		14811138	-- 24
+	);
+	
+	function sin_tbl(nsamples : integer; omega, phi_in : real) return real_array_t;
+	function cos_tbl(nsamples : integer; omega, phi_in : real) return real_array_t;
+	
+	-------------------------------------------------------------
+	-- Constructor helpers
+	-- Use: variable v8u6 : ufixed_t(ufixed(8,6)'range);
+	function uproto (nbits : integer; nbits_frac : integer) return ufixed;
+
+	-- Use: variable v8s6 : sfixed_t(sfixed(8,6)'range);
+	function sproto (nbits : integer; nbits_frac : integer) return sfixed;
+	
+end; -- package nco_pkg;
+
+-------------------------------------------------------------------------------
+package body nco_pkg is
+
+	function sin_tbl(nsamples : integer; omega, phi_in : real) return real_array_t is
+	variable tbl : real_array_t (0 to nsamples-1);
+	variable phi : real := phi_in;
+	variable dphi : real := 2.0*pi*omega;
+
+	begin
+		for i in 0 to nsamples-1 loop
+			tbl(i) := sin(phi);
+			phi := phi + dphi;
+		end loop;
+
+		return tbl;
+	end sin_tbl;
+
+	-------------------------------------------------------------
+	function cos_tbl(nsamples : integer; omega, phi_in : real) return real_array_t is
+	variable tbl : real_array_t (0 to nsamples-1);
+	variable phi : real := phi_in;
+	variable dphi : real := 2.0*pi*omega;
+
+	begin
+		for i in 0 to nsamples-1 loop
+			tbl(i) := cos(phi);
+			phi := phi + dphi;
+		end loop;
+
+		return tbl;
+	end cos_tbl;
+
+	-------------------------------------------------------------
+	-- Constuctor helpers
+	function uproto (nbits : integer; nbits_frac : integer) return ufixed is
+	constant result : ufixed (nbits-nbits_frac-1 downto -nbits_frac) := (others => '0');
+	begin 
+	return result(nbits-nbits_frac-1 downto -nbits_frac);
+	end uproto;
+
+	-------------------------------------------------------------
+	function sproto (nbits : integer; nbits_frac : integer) return sfixed is
+	constant result : sfixed (nbits-nbits_frac downto -nbits_frac+1) := (others => '0');
+	begin 
+	return result(nbits-nbits_frac downto -nbits_frac+1);
+	end sproto;
+
+-------------------------------------------------------------------------------
+end; -- package nco_pkg;