slaa228 digital fir filter design using the msp430f16x

Upload: arnochopin

Post on 23-Feb-2018

218 views

Category:

Documents


0 download

TRANSCRIPT

  • 7/24/2019 slaa228 Digital FIR Filter Design Using the MSP430F16x

    1/5

    1 T h e o r y o f O p e r a t i o n

    y(k) N

    i0i x(k i)

    ( 1 )

    A p p l i c a t i o n R e p o r t S L A A 2 2 8 N o v e m b e r 2 0 0 4

    D i g i t a l F I R F i l t e r D e s i g n U s i n g t h e M S P 4 3 0 F 1 6 x M u r u g a v e l R a j u . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M S P 4 3 0

    A B S T R A C T

    T h i s a p p l i c a t i o n r e p o r t d e s c r i b e s a n F I R f i l t e r i m p l e m e n t a t i o n u s i n g t h e M S P 4 3 0 F 1 6 x a n d t h e M S P 4 3 0 F 1 6 1 x f a m i l y d e v i c e s . T h e c o m p l e t e f i l t e r a l g o r i t h m i s e x e c u t e d b y t h e 3 - c h a n n e l D M A p e r i p h e r a l a n d t h e h a r d w a r e m u l t i p l i e r p e r i p h e r a l . T h e s e m o d u l e s a r e u s e d i n c o n j u n c t i o n w i t h t h e a l l o c a t e d c o e f f i c i e n t t a b l e i n t h e p r o g r a m m e m o r y a n d t h e c i r c u l a r d a t a b u f f e r s p a c e d e d i c a t e d i n t h e R A M o f t h e d e v i c e . T h e h a r d w a r e m u l t i p l i e r p e r f o r m s t h e s i g n e d m u l t i p l y - a n d - a c c u m u l a t e ( M A C S ) o p e r a t i o n s i n t h e a l g o r i t h m . T h e i n t e g r a t e d a n a l o g - t o - d i g i t a l c o n v e r t e r , A D C 1 2 , i s u s e d f o r d a t a a c q u i s i t i o n . T h e

    s o f t w a r e f o r t h e f i l t e r i s w r i t t e n i n s u c h a w a y t h a t a l l t h e f i l t e r p a r a m e t e r s i n c l u d i n g t h e c o e f f i c i e n t s a r e l o a d e d i n t o a l o o k - u p t a b l e . T h i s a l l o w s t h e s a m e f i l t e r p r o g r a m t o b e u s e d f o r a n y t y p e o f F I R f i l t e r i m p l e m e n t a t i o n s u c h a s h i g h - p a s s , l o w - p a s s , b a n d - p a s s a n d b a n d - r e j e c t f i l t e r s . T h e i n t e g r a t e d d i g i t a l - t o - a n a l o g c o n v e r t e r , D A C 1 2 , c a n b e u s e d f o r c o n v e r t i n g t h e f i l t e r o u t p u t b a c k i n t o t h e a n a l o g d o m a i n i f r e q u i r e d .

    D i g i t a l f i n i t e i m p u l s e r e s p o n s e ( F I R ) f i l t e r s f o r m t h e b a s i s f o r n u m e r o u s d i g i t a l s i g n a l p r o c e s s i n g a p p l i c a t i o n s . T h e b a s i c o p e r a t i o n n e e d e d t o i m p l e m e n t a F I R f i l t e r i s t h e s i g n e d m u l t i p l y - a n d - a c c u m u l a t e ( M A C S ) , w h i c h i s t r a d i t i o n a l l y p e r f o r m e d u s i n g a h a r d w a r e m u l t i p l i e r p e r i p h e r a l i n a n y D S P d e v i c e . S o m e

    o f t h e M S P 4 3 0 d e v i c e s h a v e a n i n t e g r a t e d h a r d w a r e m u l t i p l i e r t h a t c a n p e r f o r m t h i s M A C S o p e r a t i o n a l l o w i n g t h e s e d e v i c e s t o r u n t h e F I R f i l t e r a l g o r i t h m m o r e e f f i c i e n t l y t h a n d e v i c e s w i t h o u t a b u i l t - i n h a r d w a r e m u l t i p l i e r .

    E q u a t i o n 1 s h o w s a m a t h e m a t i c a l e x p r e s s i o n f o r t h e F I R f i l t e r ,

    w h e r e k i s t h e t i m e s t e p , y ( k ) i s t h e f i l t e r o u t p u t a t t i m e k , x ( k i ) i s t h e s a m p l e d i n p u t a t t i m e k i , a i i s t h e f i l t e r c o e f f i c i e n t i , a n d N i s t h e o r d e r o f t h e f i l t e r ( = n u m b e r o f t a p s 1 ) .

    I n a d d i t i o n t o t h e M A C S o p e r a t i o n t h e p r o c e s s o r h a n d l e s t h e t a s k o f m o v i n g t h e d i g i t a l s a m p l e s a n d f i l t e r c o e f f i c i e n t s f r o m m e m o r y t o t h e M A C h a r d w a r e , r e t r i e v i n g t h e r e s u l t s a n d s t o r i n g t h e m i n t o m e m o r y . I n a r e a l - t i m e d i g i t a l f i l t e r a l g o r i t h m , t h e c o m p u t a t i o n a n d m e m o r y - m o v e o p e r a t i o n s h a v e t o b e c o m p l e t e d

    w i t h i n o n e s a m p l e p e r i o d . T h e n u m b e r o f c o m p u t a t i o n s t o b e p e r f o r m e d w i t h i n o n e s a m p l e p e r i o d d e p e n d s o n t h e n u m b e r o f t a p s o f t h e f i l t e r , i . e , t h e o r d e r o f t h e f i l t e r . T h e o r d e r o f t h e f i l t e r i s d e t e r m i n e d b y t h e r e q u i r e d f i l t e r p e r f o r m a n c e c h a r a c t e r i s t i c s . W h e n h i g h e r o r d e r f i l t e r s a r e c o m b i n e d w i t h f a s t e r s a m p l i n g r a t e s , t h e d e m a n d o n t h e p r o c e s s o r b e c o m e s v e r y h i g h . T h i s l i m i t s t y p i c a l M C U s t o h a n d l e a r e a l - t i m e F I R f i l t e r a l g o r i t h m o n l y a t l o w s a m p l e r a t e s a n d w i t h a r e d u c e d n u m b e r o f f i l t e r t a p s .

    T h e M S P 4 3 0 F 1 6 9 w i t h i t s r i c h p e r i p h e r a l s e t h a n d l e s t h e F I R f i l t e r a l g o r i t h m i n a d i f f e r e n t m a n n e r c o m p a r e d t o c o n v e n t i o n a l M C U s . T h i s d e v i c e h a s a t h r e e c h a n n e l D M A p e r i p h e r a l t h a t h a n d l e s t h e r e q u i r e d d a t a , c o e f f i c i e n t a n d r e s u l t m o v e m e n t b e t w e e n t h e m e m o r y a n d t h e M A C , d r a m a t i c a l l y i m p r o v i n g t h e c o m p u t a t i o n e f f i c i e n c y o f t h e r e a l - t i m e F I R f i l t e r a l g o r i t h m r u n n i n g o n - c h i p .

    D i g i t a l F I R F i l t e r D e s i g n U s i n g t h e M S P 4 3 0 F 1 6 x S L A A 2 2 8 N o v e m b e r 2 0 0 4 1

  • 7/24/2019 slaa228 Digital FIR Filter Design Using the MSP430F16x

    2/5

    www.ti.com

    Timer_A

    TACCR2

    MCLK

    HardwareMultiplier

    MACS

    OP2

    RESHIRESLO

    DMA

    DMAChannel0

    DMA

    Channel1

    DMAChannel2

    CoefficientTable

    FIR FilterOutput Data

    a0/ak

    a1/ak1

    an/akn

    UpperandLower

    CircularBuffer

    Samples

    2 F I R F i l t e r S o f t w a r e A l g o r i t h m

    F I R F i l t e r S o f t w a r e A l g o r i t h m

    T h e D M A p e r i p h e r a l c o m p l e t e s a m e m o r y t r a n s f e r o p e r a t i o n i n t w o C P U c l o c k c y c l e s . A d d i t i o n a l l y i t h a s s o f t w a r e - s e l e c t a b l e t r i g g e r s o u r c e s t h a t m a k e i t i d e a l l y s u i t a b l e f o r t h e F I R f i l t e r i m p l e m e n t a t i o n . T h e F I R f i l t e r r u n s o n t h e D M A - M A C S - M e m o r y c o m b i n a t i o n a u t o n o m o u s l y w i t h o u t t h e i n t e r v e n t i o n o f t h e C P U . T h e C P U i s p r i m a r i l y o n l y b e i n g u s e d f o r t h e i n i t i a l i z a t i o n o f p e r i p h e r a l s .

    T h e c o e f f i c i e n t s o f t h e F I R f i l t e r a r e s y m m e t r i c a l i n n a t u r e . D u e t o t h i s t h e c o e f f i c i e n t t a b l e s i z e c a n b e r e d u c e d t o h a l f t h e n u m b e r o f t a p s o f t h e f i l t e r . I n a D S P d e v i c e t h e i n p u t s a m p l e d a t a i s s t o r e d i n a

    c i r c u l a r b u f f e r t o i m p l e m e n t t h e m o v e m e n t o f t h e s a m p l e s t h r o u g h t h e F I R c o m p u t a t i o n b l o c k s w i t h o u t h a v i n g t o l i t e r a l l y m o v e t h e d a t a i n m e m o r y . W h e n a n e w s a m p l e i s a d d e d t o t h e b u f f e r , i t a u t o m a t i c a l l y r e p l a c e s t h e o l d e s t o n e . A s i m i l a r c i r c u l a r b u f f e r a r r a n g e m e n t i s m a d e i n t h e l i n e a r m e m o r y s p a c e o f t h e M S P 4 3 0 b y a f o l d e d a d d r e s s s t r u c t u r e a p p r o a c h u s i n g D M A c h a n n e l s 1 a n d 2 . F i g u r e 1 r e p r e s e n t s t h e b l o c k d i a g r a m o f t h e F I R f i l t e r i m p l e m e n t a t i o n i n t h e M S P 4 3 0 F 1 6 9 .

    F i g u r e 1 . F I R I m p l e m e n t a t i o n U s i n g t h e M S P 4 3 0 F 1 6 9

    T h e F I R f i l t e r s o f t w a r e f o r t h e M S P 4 3 0 F 1 6 9 i s w r i t t e n i n a s s e m b l y l a n g u a g e t o a c h i e v e m a x i m u m p e r f o r m a n c e . T h e s o f t w a r e i s w r i t t e n t o a c c e p t t h e c o e f f i c i e n t s s t o r e d i n t h e f o r m o f a l o o k - u p t a b l e p o i n t e d t o b y t h e l a b e l F I L T E R i n p r o g r a m m e m o r y . T h e f i r s t v a l u e i n t h e l o o k - u p t a b l e i s t h e v a l u e f o r T i m e r _ A f o r t h e r e q u i r e d s a m p l i n g f r e q u e n c y . T h e n e x t v a l u e i s t h e n u m b e r o f f i l t e r t a p s N a n d t h e r e m a i n i n g v a l u e s a r e f i l t e r c o e f f i c i e n t s .

    D i g i t a l F I R F i l t e r D e s i g n U s i n g t h e M S P 4 3 0 F 1 6 x 2 S L A A 2 2 8 N o v e m b e r 2 0 0 4

  • 7/24/2019 slaa228 Digital FIR Filter Design Using the MSP430F16x

    3/5

    www.ti.com

    3 D e m o S o f t w a r e

    4 C a l c u l a t i n g t h e F I R F i l t e r C o e f f i c i e n t s

    5 C o n c l u s i o n

    D e m o S o f t w a r e

    T h e d e p t h o f t h e R A M b u f f e r i s 2 x t h e n u m b e r o f t a p s t o m i n i m i z e t h e c i r c u l a r b u f f e r o v e r h e a d . I n t h i s i m p l e m e n t a t i o n n o a d d i t i o n a l i n p u t o r o u t p u t b u f f e r s t o t h e f i l t e r s t r u c t u r e a r e p r o v i d e d . T h e s e c a n b e a d d e d t o m i n i m i z e o r e l i m i n a t e t h e e f f e c t o f i n t e r r u p t l a t e n c y .

    T h e D M A i s c o n f i g u r e d a s f o l l o w s :

    D M A 0 : L o a d s t h e f i l t e r c o e f f i c i e n t s f r o m t h e l o o k - u p t a b l e t o t h e h a r d w a r e m u l t i p l i e r s i g n e d m u l t i p l y a n d a c c u m u l a t e ( M A C S ) r e g i s t e r

    D M A 1 : S e n d s s a m p l e d a t a t o M A C a n d m o v e s t h e u p - d i r e c t i o n s a m p l e p o i n t e r o f t h e c i r c u l a r b u f f e r

    D M A 2 : S e n d s s a m p l e d a t a t o M A C a n d m o v e s t h e d o w n - d i r e c t i o n s a m p l e p o i n t e r o f t h e c i r c u l a r b u f f e r

    T h e t h r e e D M A c h a n n e l s a r e e n a b l e d a n d d i s a b l e d t o g e t h e r b y m o d u l a t i n g t h e T A C C R 0 r e g i s t e r v a l u e b e t w e e n 0 x 0 0 ( d i s a b l e d ) a n d 0 x 0 B ( t r i g g e r s e v e r y 1 2 c l o c k s ) .

    T h e c o m p u t a t i o n t a k e s a d v a n t a g e o f t h e s y m m e t r i c a l n a t u r e o f t h e F I R f i l t e r s t r u c t u r e a s m e n t i o n e d i n t h e e a r l i e r s e c t i o n s . T h i s a l g o r i t h m l o a d s t h e f i r s t c o e f f i c i e n t v a l u e t o t h e M A C S r e g i s t e r v i a D M A 0 a n d t h e n m o v e s t w o s a m p l e s s e q u e n t i a l l y t o t h e O P 2 r e g i s t e r o f t h e h a r d w a r e m u l t i p l i e r . T h e f i r s t s a m p l e i s l o a d e d b y D M A 1 a n d t h e s e c o n d s a m p l e b y D M A 2 . D M A 1 s c a n s t h r o u g h t h e u p p e r h a l f o f t h e s a m p l e s w i n d o w b y i n c r e m e n t i n g t h e s o u r c e a d d r e s s a f t e r e v e r y t r a n s f e r a n d D M A 2 s c a n s t h r o u g h t h e l o w e r h a l f o f t h e s a m p l e s w i n d o w b y d e c r e m e n t i n g t h e s o u r c e a d d r e s s a f t e r e v e r y t r a n s f e r .

    D u e t o t h e s y m m e t r y o f t h e c o e f f i c i e n t v a l u e s o n l y h a l f o f t h e c o e f f i c i e n t s a r e s t o r e d i n t h e l o o k - u p t a b l e . I f t h e n u m b e r o f t a p s , N , i s e v e n t h e f i r s t h a l f i s s t o r e d . I f N i s o d d , t h e n t h e n u m b e r o f c o e f f i c i e n t s s t o r e d i s ( N + 1 ) / 2 w i t h t h e l a s t c o e f f i c i e n t v a l u e d i v i d e d b y t w o .

    T h e a s s e m b l y s o u r c e c o d e f o r t h i s a l g o r i t h m i s i n c l u d e d i n t h e d e m o c o d e p r o v i d e d a s a . z i p f i l e a l o n g w i t h t h i s a p p l i c a t i o n r e p o r t . T h e s o u r c e c o d e c a n b e t a i l o r e d t o s p e c i f i c n e e d s o f a n a p p l i c a t i o n a s r e q u i r e d .

    T h e d e m o s o f t w a r e i n c l u d e d w i t h t h i s a p p l i c a t i o n r e p o r t u t i l i z e s t h e a l g o r i t h m d e s c r i b e d a b o v e . T h e i n p u t s a m p l e s a r e p r o v i d e d d i r e c t l y t o t h e f i l t e r i n p u t a n d t o t h e i n t e g r a t e d d i g i t a l - t o - a n a l o g c o n v e r t e r , D A C 0 , b y a s w e e p f r e q u e n c y g e n e r a t e d u s i n g t h e 1 2 - b i t l o o k u p t a b l e v a l u e s f r o m t h e a t t a c h e d s i n e w a v e d a t a f i l e : s i n e 8 1 9 2 _ 1 2 b . d a t . T h e f i l t e r p a r a m e t e r s a r e s t o r e d i n t h e p r o g r a m m e m o r y p o i n t e d b y t h e l a b e l F i l t e r . T h r e e e x a m p l e s a r e s h o w n : a 4 0 - t a p l o w - p a s s f i l t e r , a 2 2 4 - t a p b a n d - p a s s f i l t e r a n d a 1 0 1 - t a p b a n d - s t o p

    f i l t e r . T h e f i l t e r o u t p u t i s s e n t t o D A C 1 a n d c a n b e c o n n e c t e d t o a n o s c i l l o s c o p e f o r v i e w i n g o f t h e f i l t e r o u t p u t r e s p o n s e . T h e c o r r e s p o n d i n g i n p u t w a v e f o r m c a n b e s e e n a t t h e D A C 0 o u t p u t u s i n g a n o t h e r c h a n n e l o f t h e o s c i l l o s c o p e . W h e n t h e p r o g r a m i s d o w n l o a d e d t o t h e d e v i c e a n d e x e c u t e d t h e i n p u t f r e q u e n c y s w e e p s t h r o u g h t h e s e t r a n g e . T h e o u t p u t r e s p o n s e c a n b e s e e n o n t h e c h a n n e l c o n n e c t e d t o D A C 1 o u t p u t . T h e a p p r o p r i a t e f i l t e r f o r e x e c u t i o n i s s e l e c t e d b y c o m m e n t i n g o u t t h e u n w a n t e d f i l t e r t a b l e l a b e l s .

    T h e d e m o s o f t w a r e c a n b e r u n o n a F E T 1 4 0 w i t h a M S P 4 3 0 F 1 6 9 p o p u l a t e d i n t h e s o c k e t . N o t e t h a t t h e F E T t a r g e t b o a r d d o e s n o t h a v e a n 8 M H z h i g h f r e q u e n c y c r y s t a l o r r e s o n a t o r c o n n e c t e d t o i t a n d m u s t b e p o p u l a t e d f o r t h i s d e m o s o f t w a r e t o f u n c t i o n a s i s . T h e s o f t w a r e p r o v i d e d w i t h t h i s r e p o r t i s f o r I A R e m b e d d e d w o r k b e n c h K i c k s t a r t v e r s i o n w h i c h c a n b e d o w n l o a d e d f o r f r e e f r o m t h e M S P 4 3 0 w e b p a g e .

    T h e f i l t e r c o e f f i c i e n t s a n d t h e o r d e r o f t h e f i l t e r a r e c a l c u l a t e d a s p e r t h e r e q u i r e m e n t s o f t h e f i l t e r t y p e a n d p a r a m e t e r s . T h i s a p p l i c a t i o n u s e s a v e r y i n e x p e n s i v e p r o g r a m c a l l e d S c o p e F I R f r o m w w w . i o w e g i a n . c o m . N o t o n l y d o e s t h i s p r o g r a m c a l c u l a t e t h e f i l t e r c o e f f i c i e n t s b u t a l s o s i m u l a t e s t h e f i l t e r r e s p o n s e s f o r a l l t y p e s o f F I R f i l t e r s . T h e c a l c u l a t e d c o e f f i c i e n t s c a n b e c o n v e r t e d t o s i g n e d f r a c t i o n h e x f o r m a t b y c h a n g i n g t h e d a t a f o r m a t a n d c a n b e i m p o r t e d a s t e x t o r e a s i l y c o p i e d a n d p a s t e d i n t o t h e a s s e m b l e r s o u r c e c o d e .

    T h e t h r e e c h a n n e l D M A p e r i p h e r a l w i t h v a r i o u s t r i g g e r s a n d t h e h a r d w a r e m u l t i p l i e r a l l o w s r e a l i z a t i o n o f v e r y e f f i c i e n t F I R f i l t e r a l g o r i t h m s u s i n g t h e M S P 4 3 0 F 1 6 9 . A c h i e v i n g a h i g h e r n u m b e r o f t a p s w i t h f a s t e r s a m p l i n g r a t e i s m a d e p o s s i b l e w i t h t h i s i m p l e m e n t a t i o n u n l i k e u s i n g c o n v e n t i o n a l M C U s t h a t d o n o t h a v e a h a r d w a r e m u l t i p l i e r t o p e r f o r m M A C S a n d t h e m u l t i - c h a n n e l D M A t o e x e c u t e t h e f i l t e r a l g o r i t h m .

    D i g i t a l F I R F i l t e r D e s i g n U s i n g t h e M S P 4 3 0 F 1 6 x S L A A 2 2 8 N o v e m b e r 2 0 0 4 3

  • 7/24/2019 slaa228 Digital FIR Filter Design Using the MSP430F16x

    4/5

    www.ti.com

    6 R e f e r e n c e s

    R e f e r e n c e s

    T a b l e 1 s h o w s t h e p e r f o r m a n c e t h a t c a n b e a c h i e v e d u s i n g t h e M S P 4 3 0 F 1 6 9 w i t h a n 8 M H z C P U c l o c k f r e q u e n c y w i t h r e s p e c t t o f i l t e r t a p s a n d t h e m a x i m u m s a m p l i n g r a t e p o s s i b l e w i t h 1 0 0 % C P U l o a d i n g .

    T a b l e 1 . M S P 4 3 0 F 1 6 9 F I R F i l t e r B e n c h m a r k s

    N u m b e r o f T a p s , M a x i m u m S a m p l i n g R a t e ( k H z ) N u m b e r o f C P U C l o c k s

    N ( 1 0 0 % C P U l o a d i n g )

    3 2 3 1 0 2 5

    5 0 4 1 0 1 9

    1 0 0 7 3 0 1 1

    P r a c t i c a l s i g n a l p r o c e s s i n g n e e d s a r e t y p i c a l l y m u c h l o w e r t h a n t h e m a x i m u m p o s s i b l e n u m b e r s s h o w n i n t h e t a b l e . I n s u c h c a s e s m o r e f r e e C P U r e s o u r c e s w i l l b e a v a i l a b l e f o r t h e u s e r a p p l i c a t i o n w h i l e r u n n i n g t h e F I R f i l t e r

    1 . U n d e r s t a n d i n g D i g i t a l S i g n a l P r o c e s s i n g b y R i c h a r d G . L y o n s

    2 . T h e S c i e n t i s t a n d E n g i n e e r s G u i d e t o D i g i t a l S i g n a l P r o c e s s i n g b y S t e v e n W . S m i t h 3 . M S P 4 3 0 x 1 x x F a m i l y U s e r s G u i d e ( S L A U 0 4 9 )

    4 . M S P 4 3 0 x 1 6 x D a t a s h e e t ( S L A S 3 6 8 )

    D i g i t a l F I R F i l t e r D e s i g n U s i n g t h e M S P 4 3 0 F 1 6 x 4 S L A A 2 2 8 N o v e m b e r 2 0 0 4

    http://www-s.ti.com/sc/techlit/SLAS368http://www-s.ti.com/sc/techlit/SLAU049
  • 7/24/2019 slaa228 Digital FIR Filter Design Using the MSP430F16x

    5/5

    IMPORTANT NOTICE

    Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications,

    enhancements, improvements, and other changes to its products and services at any time and to discontinue

    any product or service without notice. Customers should obtain the latest relevant information before placing

    orders and should verify that such information is current and complete. All products are sold subject to TIs terms

    and conditions of sale supplied at the time of order acknowledgment.

    TI warrants performance of its hardware products to the specifications applicable at the time of sale in

    accordance with TIs standard warranty. Testing and other quality control techniques are used to the extent TI

    deems necessary to support this warranty. Except where mandated by government requirements, testing of all

    parameters of each product is not necessarily performed.

    TI assumes no liability for applications assistance or customer product design. Customers are responsible for

    their products and applications using TI components. To minimize the risks associated with customer products

    and applications, customers should provide adequate design and operating safeguards.

    TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right,

    copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process

    in which TI products or services are used. Information published by TI regarding third-party products or services

    does not constitute a license from TI to use such products or services or a warranty or endorsement thereof.Use of such information may require a license from a third party under the patents or other intellectual property

    of the third party, or a license from TI under the patents or other intellectual property of TI.

    Reproduction of information in TI data books or data sheets is permissible only if reproduction is without

    alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction

    of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for

    such altered documentation.

    Resale of TI products or services with statements different from or beyond the parameters stated by TI for that

    product or service voids all express and any implied warranties for the associated TI product or service and

    is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.

    Following are URLs where you can obtain information on other Texas Instruments products and application

    solutions:

    Products Applications

    Amplifiers amplifier.ti.com Audio www.ti.com/audio

    Data Converters dataconverter.ti.com Automotive www.ti.com/automotive

    DSP dsp.ti.com Broadband www.ti.com/broadband

    Interface interface.ti.com Digital Control www.ti.com/digitalcontrol

    Logic logic.ti.com Military www.ti.com/military

    Power Mgmt power.ti.com Optical Networking www.ti.com/opticalnetwork

    Microcontrollers microcontroller.ti.com Security www.ti.com/security

    Telephony www.ti.com/telephony

    Video & Imaging www.ti.com/video

    Wireless www.ti.com/wireless

    Mailing Address: Texas Instruments

    Post Office Box 655303 Dallas, Texas 75265

    Copyright 2005, Texas Instruments Incorporated

    http://amplifier.ti.com/http://www.ti.com/audiohttp://dataconverter.ti.com/http://www.ti.com/automotivehttp://dsp.ti.com/http://www.ti.com/broadbandhttp://interface.ti.com/http://www.ti.com/digitalcontrolhttp://logic.ti.com/http://www.ti.com/militaryhttp://power.ti.com/http://www.ti.com/opticalnetworkhttp://microcontroller.ti.com/http://www.ti.com/securityhttp://www.ti.com/telephonyhttp://www.ti.com/videohttp://www.ti.com/wirelesshttp://www.ti.com/wirelesshttp://www.ti.com/videohttp://www.ti.com/telephonyhttp://www.ti.com/securityhttp://www.ti.com/opticalnetworkhttp://www.ti.com/militaryhttp://www.ti.com/digitalcontrolhttp://www.ti.com/broadbandhttp://www.ti.com/automotivehttp://www.ti.com/audiohttp://microcontroller.ti.com/http://power.ti.com/http://logic.ti.com/http://interface.ti.com/http://dsp.ti.com/http://dataconverter.ti.com/http://amplifier.ti.com/