fft 997 ver.3 Data Sheet fftfftmegacore FLEX K twiddle Deciatio i Frequecy FFT twiddle MegaCore fft DSP MegaCore fft fft data_left_i_re[] data_left_i_i[] we_left add_left[] clock start_fft twiddle_re[] twiddle_i[] add_twiddle[] FFT data_right_i_re[] data_right_i_i[] we_right add_right[] doe data_directio expoet[] data_out_re[] data_out_i[] PIPE_DATA= PIPE_TWIDDLE= WIDTH_ADD= WIDTH_DATA= WIDTH_EXPONENT= WIDTH_TWIDDLE= twiddle Altera Corporatio Page A-DS-FFT-3/J L-5783-/J
fft Fast Fourier Trasfor Data Sheet FLEX K EAB RAM AHDL Fuctio Prototype fftahdlfuctio Prototype FUNCTION fft (clock, start_fft, data_left_i_re[width_data-..], data_left_i_i[width_data-..], data_right_i_re[width_data-..], data_right_i_i[width_data-..], twiddle_re[width_twiddle-..], twiddle_i[width_twiddle-..]) WITH (WIDTH_DATA, WIDTH_TWIDDLE, PIPE_DATA, PIPE_TWIDDLE, WIDTH_EXPONENT, FFT_DIRECTION, WIDTH_ADD, EXPONENT_INITIAL_VALUE) RETURNS (doe, data_directio, we_left, add_left[width_add-..], we_right, add_right[width_add-..], add_twiddle[width_add-2..], data_out_re[width_data-..], data_out_i[width_data-..], expoet[width_exponent-..]); VHDL Copoet Declaratio fftvhdl Copoet Declaratio COMPONENT fft GENERIC( WIDTH_DATA : POSITIVE; WIDTH_TWIDDLE : POSITIVE; PIPE_DATA : INTEGER; PIPE_TWIDDLE : INTEGER; WIDTH_EXPONENT : POSITIVE; WIDTH_ADD : POSITIVE; EXPONENT_INITIAL_VALUE : INTEGER); PORT( clock : IN STD_LOGIC := ''; start_fft : IN STD_LOGIC; data_left_i_re, data_left_i_i, data_right_i_re, data_right_i_i : IN STD_LOGIC_VECTOR(WIDTH_DATA- DOWNTO ); twiddle_re, twiddle_i : IN STD_LOGIC_VECTOR(WIDTH_TWIDDLE- DOWNTO ); Page 2 Altera Corporatio
fft Fast Fourier Trasfor Data Sheet doe, data_directio, we_left : OUT STD_LOGIC; add_left : OUT STD_LOGIC_VECTOR(WIDTH_ADD- DOWNTO ); we_right : OUT STD_LOGIC; add_right : OUT STD_LOGIC_VECTOR(WIDTH_ADD- DOWNTO ); add_twiddle : OUT STD_LOGIC_VECTOR(WIDTH_ADD-2 DOWNTO ); data_out_re, data_out_i : OUT STD_LOGIC_VECTOR(WIDTH_DATA- DOWNTO ); expoet : OUT_STD_LOGIC_VECTOR(WIDTH_EXPONENT- DOWNTO )); END COMPONENT; fft fft clock start_fft fft data_left_i_re[] fft data_left_i_i[] fft data_right_i_re[] fft data_right_i_i[] fft twiddle_re[] fft twiddle_i[] fft doe fft data_directio fft we_left we_right add_left[] add_right[] add_twiddle[] data_out_re[] fft data_out_i[] fft expoet[] doe Altera Corporatio Page 3
fft Fast Fourier Trasfor Data Sheet fft fft PIPE_DTA add_left[] add_right[] data_left_i_re [] data_left_i_i[] data_right_i_re[] data_right_i_i[] PIPE_TWIDDLE add_twiddle[] twiddle_re[] twiddle_i[] WIDTH_ADD fft 2 WIDTH_ADD WIDTH_DATA WIDTH_EXPONENT WIDTH_TWIDDLE fft Deciatio I Frequecy DIF FFT fft I/O I/O DIF DIF FFT x[] X[] x[] X[] = x[] X[] x[] X[] W k N X[] = x[] + x[] X[] = W k N (x[] x[]) k W N = Twiddle = e j 2πk/N = cos(2πk/n) jsi(2πk/n) k = to (N/2 ) N = j = W k N Page 4 Altera Corporatio
fft Fast Fourier Trasfor Data Sheet DIF FFT fft DIF FFT Pass Pass 2 Pass 3 x[] x[] W 8 W 8 W 8 X[] X[] x[] x[] W 8 W 8 W 8 X[] X[] 2 3 x[] x[] W 2 8 W 2 8 W 8 X[] X[] 4 5 x[] x[] W 3 8 W 2 8 W 8 X[] X[] 6 7 Right Meory Left Meory Right Meory Left Meory Address fft_o_chipi/o fft_o_chip fft Pass-fft Pass-2 fft DIF fft Altera Corporatio Page 5
fft Fast Fourier Trasfor Data Sheet fft fft 2 3 2 5 =32 fft 2 4 =6 2 6 =64fft data_directiofft fft W WN k ( e j 2π k )/ = N = cos ( 2πk/ N) jsi( 2πk/ N) N = fft = WIDTH_ADD k = to (N/2 ) j = cos(2πk/n) si(2πk/n) MegaCore fft twiddleeab.if MIF ROM UNIX DOStwiddle fft WIDTH_DATA.5. B.5. B. WIDTHTWIDDLE- 2 27 9922 WIDTHTWIDDLE- = =. 2 28 Page 6 Altera Corporatio
fft Fast Fourier Trasfor Data Sheet.5. B.5. B W N.+j WN W N /4 FFT fft FFT I/O I/O FLEX K FLEX K EPFK EPFK5 EPFK EPFK5 Poits EABs Poits EABs Poits EABs EPFK 2 8 8 52 2,48 8 52 8 9 to 6 8 256 2,48 8 256 8 9 to 6 9 to 6 256 2,24 8 256 8 > 6 > 6 EPFK5 8 8 52 2,48 8 52 8 9 to 6 8 256 2,48 8 256 8 9 to 6 9 to 6,24 8 256 8 > 6 > 6 () RAM (2) RAM Altera Corporatio Page 7
fft Fast Fourier Trasfor Data Sheet RAM fft_o_chip fft_o_chip ROM PIPE_TWIDDLE RAM PIPE_DATA fft I/O I/O RAM RAM RAM RAM fft_o_chip FLEX K EAB fft fft Page 8 Altera Corporatio
fft Fast Fourier Trasfor Data Sheet load_bak_eable load_bak_reset e Load Couter sclr q uload_bak_eable uload_bak_reset e Uload Couter sclr q load_ru data_out_re[] data_out_i[] Left Meory start_fft q[] we add[] d data_left_i[] we_left add_left[] start_fft fft data_right_i[] we_right add_right[] q[] we add[] d Right Meory Twiddle Meory q add r - twiddle_i[] add_twiddle[] doe expoet[] data_out[] p doe expoet[] data_i = 2 WIDTH_DATA = WIDTH_ADD p = WIDTH_EXPONENT r = WIDTH_TWIDDLE I/O fftfft fft I/O EAB PIPE_DATA Altera Corporatio Page 9
fft Fast Fourier Trasfor Data Sheet fft I/O doe I/O fft PIPE_TWIDDLE load_ru N+ load_bak_eable N data_i load_ru fft start_fft fft fft doe fft fft FFTfft FFT FFT fft fft I/O Page Altera Corporatio
fft Fast Fourier Trasfor Data Sheet load_bak_eable data_i left_address right_address data_i load_bak_eable load_bak_reset e Load Couter sclr q uload_bak_eable uload_bak_reset e Uload Couter sclr q load_ru data_out_re[] data_out_i[] start_fft Left q[] Meory we add[] Twiddle Meory d add[] q[] r data_left_i[] we_left add_left[] start_fft twiddle_i[] add_twiddle[] fft data_right_i[] we_right add_right[] doe expoet[] data_out[] p q[] Right we Meory add[] d doe expoet[] data_i = WIDTH_ADD = 2 WIDTH_DATA p = WIDTH_EXPONENT r = WIDTH_TWIDDLE Altera Corporatio Page
fft Fast Fourier Trasfor Data Sheet RAM fft 256 RAM SSRAM fft FFT SSRAM RAM RAM RAM RAM data_i data_out FLEX K fft RAM fft - - - -fft fft-- - - fft -- -- start_fft- - fft-- -- AItera Corporatio Iovatio Drive, Sa Jose, CA 9534 TEL : (48) 544-7 http://www.altera.co http://www.altera.co