fftdatatypelib.vhd

基于存储器的基4按频率抽取的fft 的vhdl描述 可以对连续数据流进行256点的fft

library ieee;
	use ieee.std_logic_1164.all;
	use IEEE.std_logic_arith.all;
	--
   use IEEE.math_real.all;
	use IEEE.math_complex.all;
	
package fftDataType is
    --subtype slvDt is std_logic_vector(Aw -1 downto 0);
	Constant CoefWidth : natural := 14;
	Constant DataWidth : natural := 16;
	
	subtype slvDt is std_logic_vector(2*DataWidth-1 downto 0);
	subtype slvDtSub is signed(DataWidth-1 downto 0);
	--constant slvDtRstV : slvDt := math_czero;
	--constant slvDtRotJ : slvDt := math_cbase_j;
	---
	subtype slvCoeft is std_logic_vector(2*CoefWidth-1 downto 0);
	subtype slvCoeftSub is signed(CoefWidth -1 downto 0);
	--constant slvCoeftWn : slvCoeft := exp( -math_cbase_j* math_2_pi / real(2** Addrw));
	--
	---data type arithmetic
	-- + -
--	function DtAdd(a, b : in slvDt) return slvDt;
--	function DtSub(a, b : in slvDt) return slvDt;
	--
--	function DtScaleAdd(a, b : in slvDt) return slvDt;
--	function DtScaleSub(a, b : in slvDt) return slvDt;
	-- * 
	--function DtMulCoef(a : in slvDt; b : in slvCoeft) return slvDt;
	-- * j
--	function DtRotJ(a : in slvDt) return slvDt;
	--
	
	
	--
	function DtGetRe(d : in slvDt) return slvDtSub;
	function DtGetIm(d : in slvDt) return slvDtSub;
	--
	function CoeftGetRe(d : in slvCoeft) return slvCoeftSub;
	function CoeftGetIm(d : in slvCoeft) return slvCoeftSub;
	--
--	function DtMulCoef(d : in slvDtSub; c : slvCoeftSub) return slvDtSub;
	--
	function CreateDt(r, i: slvDtSub) return slvDt;
	function CreateDt(r, i: real) return slvDt;
	function DttoComplex(dt : slvDt) return complex;

	function CreateCoeft(r, i : slvCoeftSub) return slvCoeft;
	function CreateCoeft(r, i: real) return slvCoeft;
--	
--	function DtSubAdd(a,b : in slvDtSub) return slvDtSub;
	function DtSubNeg(a : in slvDtSub) return slvDtSub;
	
	function signedToReal(d : signed; Width : integer) return real ;
end package fftDataType;

package body fftDataType is
    --function CstrCoef
--     -- +
--		function DtSubAdd(a,b : in slvDtSub) return slvDtSub is
--			begin
--				return conv_signed(signed(a) + signed(b), DataWidth);
--			end function DtSubAdd;
		
--		function DtSubSub(a,b : in slvDtSub) return slvDtSub is
--			begin
--				return conv_std_logic_vector(signed(a) - signed(b), DataWidth);
--			end function DtSubSub;
		
		
		function DtSubNeg(a : in slvDtSub) return slvDtSub is
			begin
				return conv_signed(-signed(a), DataWidth);
			end function DtSubNeg;
			
--		function DtAdd(a, b : in slvDt) return slvDt is
--		 begin
--			 return conv_std_logic_vector(signed(DtGetRe(a)) + signed(DtGetRe(b)), DataWidth
--						)
--						&
--						conv_std_logic_vector(signed(DtGetIm(a)) + signed(DtGetIm(b)), DataWidth)
--						;
--		 end function DtAdd;
--		-- -
--		function DtSub(a, b : in slvDt) return slvDt is
--			begin
--				return conv_std_logic_vector(signed(DtGetRe(a)) - signed(DtGetRe(b)), DataWidth)
--						&
--						conv_std_logic_vector(signed(DtGetIm(a)) - signed(DtGetIm(b)), DataWidth)
--						;
--		 end function DtSub;
		 
--		function DtScaleAdd(a, b : in slvDt) return slvDt is
--				variable sum : slvDt;
--				variable r : signed(DataWidth downto 0);
--				variable i : signed(DataWidth downto 0);
--				constant u1 : unsigned := "1";
--			begin
--				r := conv_signed(DtGetRe(a),DataWidth +1) + conv_signed(DtGetRe(b),DataWidth +1);
--				i := conv_signed(DtGetIm(a),DataWidth +1) + conv_signed(DtGetIm(b),DataWidth +1);
--				sum := (conv_std_logic_vector(r(DataWidth downto 1),DataWidth))
--						&
--						(conv_std_logic_vector(i(DataWidth downto 1),DataWidth));
--			 return sum;
--		 end function DtScaleAdd;
--		-- -
--		function DtScaleSub(a, b : in slvDt) return slvDt is
--				variable sum : slvDt;
--				variable r : signed(DataWidth downto 0);
--				variable i : signed(DataWidth downto 0);
--				constant u1 : unsigned := "1";
--			begin
--				r := conv_signed(DtGetRe(a),DataWidth +1) - conv_signed(DtGetRe(b),DataWidth +1);
--				i := conv_signed(DtGetIm(a),DataWidth +1) - conv_signed(DtGetIm(b),DataWidth +1);
--				sum := (conv_std_logic_vector(r(DataWidth downto 1),DataWidth))
--						&
--						(conv_std_logic_vector(i(DataWidth downto 1),DataWidth));
--			 return sum;
--		 end function DtScaleSub;
		 
		-- *j
--		function DtRotJ(a : in slvDt) return slvDt is
--		 begin
--			  return conv_std_logic_vector(-DtGetIm(a), DataWidth)& std_logic_vector(DtGetRe(a));
--		 end function DtRotJ; 
		-- *
		function signedToReal(d : signed; Width : integer) return real is
			begin
				if not Is_X(d(d'left)) then
					return real(conv_integer(
								d
						))/real(2 ** (Width -1 ));
				else
					return 0.0;
				end if;
			end function signedToReal;
			
--		function DtMulCoef(d : in slvDtSub; c : slvCoeftSub) return slvDtSub is
--				variable r : signed(d'length + c'length -1 downto 0);
--				variable cr : signed(DataWidth -1 downto 0);
--				variable dd,dc,dr,mul, eps : real;
--			begin
--				
--				r := signed(d)*signed(c);
--				r := r(r'left -1 downto 0) & '0';
--				
--				dd := signedToreal(d,d'length);
--				dc := signedToreal(c,c'length);
--				mul := dd * dc;
--				
--				dr := signedToreal(r,r'length);
--				
--				
--				eps := abs(
--						dr - dd*dc
--					);
--				
--				
--				cr := conv_signed(integer(dr * real(2 ** (DataWidth -1 ))),cr'length);
--				
--				if eps /= 0.0 then
--					assert eps <1.5e-5
--						report "DtMul error too large!"
--						severity warning;
--				end if;
--				return slvDtSub(r(r'left downto r'left - DataWidth +1));
--			end function DtMulCoef;
		--get real
		function DtGetRe(d : in slvDt) return slvDtSub is
			variable r : slvDtSub;
		 begin
			r := slvDtSub(d(2*DataWidth-1 downto Datawidth));
			  return r;
		 end function DtGetRe;
		
		--get real
		function DtGetIm(d : in slvDt) return slvDtSub is
		 begin
				return slvDtSub(d(DataWidth-1 downto 0));
		 end function DtGetIm;
		 
		--get real
		function CoeftGetRe(d : in slvCoeft) return slvCoeftSub is
			variable r : slvCoeftSub; 
		 begin
				r := slvCoeftSub(d(2*CoefWidth-1 downto Coefwidth));
				return r;
		 end function CoeftGetRe;
		
		--get Imagine
		function CoeftGetIm(d : in slvCoeft) return slvCoeftSub is
		 begin
				 return slvCoeftSub(d(CoefWidth-1 downto 0));
		 end function CoeftGetIm;
		 
		function CreateDt(r, i: slvDtSub) return slvDt is
			begin
				return std_logic_vector(r) & std_logic_vector(i);
			end function CreateDt;
			
		function CreateDt(r, i: real) return slvDt is
				variable ir, ii : integer;
			begin
					ir := integer(r * real(2 ** (DataWidth -1 ))) ;
					ii := integer(i * real(2 ** (DataWidth -1 )));
				return CreateDt(conv_signed(ir,DataWidth),conv_signed(ii,DataWidth) );
			end function CreateDt;
			
		function DttoComplex(dt : slvDt) return complex is
				--variable cc : slvDt;
				variable rr, ri : real;
				variable c : complex;
			begin
					rr := real(conv_integer(
						dtGetRe(dt)
						))/real(2 ** (DataWidth -1 ));
					ri := real(conv_integer(
						dtGetIm(dt)
						))/real(2 ** (DataWidth -1 ));
					c := (rr,ri);
					return c;
			end function DttoComplex;
			
		function CreateCoeft(r, i : slvCoeftSub) return slvCoeft is
			begin
				return std_logic_vector(r) & std_logic_vector(i);
			end function CreateCoeft;
			
		function CreateCoeft(r, i: real) return slvCoeft is
				variable ir, ii : integer;
			begin
					ir := integer(r * real(2 ** (CoefWidth -1 ))) ;
					ii := integer(i * real(2 ** (CoefWidth -1 )));
				return CreateCoeft(conv_signed(ir,CoefWidth),conv_signed(ii,CoefWidth) );
			end function CreateCoeft;
end package body fftDataType;