WP413812 S LAMU Intel, WP413812 S LAMU Datasheet - Page 25

• Manufacturer Part Number: WP413812 S LAMU
• Manufacturer: Intel

Specifications of WP413812 S LAMU

• Lead Free Status / RoHS Status: Compliant

P a c k a g e I n f o r m a t i o n — I n t e l
T a b l e 9 .
O c t o b e r 2 0 0 7
O r d e r N u m b e r : 3 1 7 8 0 6 - 0 0 1 U S
U A R T S i g n a l s ( S h e e t 1 o f 2 )
U 0 _ R X D
U 0 _ T X D
U 0 _ C T S #
U 0 _ R T S #
U1_RXD
N a m e
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4 1 3 8 0 8 a n d 4 1 3 8 1 2
C o u n t
1
1
1
1
1
A c t L o w
A c t L o w
Async
T y p e
Async
Async
Async
Async
O
O
I
I
I
I n t e l
U A R T 0 S e r i a l I n p u t : S e r i a l d a t a i n p u t f r o m d e v i c e p i n t o t h e r e c e i v e
s h i f t r e g i s t e r .
U A R T 0 S e r i a l O u t p u t : C o m p o s i t e s e r i a l d a t a o u t p u t t o t h e
c o m m u n i c a t i o n s l i n k - p e r i p h e r a l , m o d e m , o r d a t a s e t . T h e T X D
s i g n a l i s s e t t o t h e M A R K I N G ( l o g i c 1 ) s t a t e u p o n a r e s e t o p e r a t i o n .
UART 0 Clear to Send: When low, this pin indicates that the receiving UART
is ready to receive data. When the receiving UART deasserts
transmitting UART must stop transmission to prevent overflow of the
receiving UART buffer. The
condition can be tested by the host processor or by the UART when in
Autoflow Mode as described below:
N o t e :
U A R T 0 R e q u e s t t o S e n d : T h i s b i t i n d i c a t e s t o t h e r e m o t e d e v i c e
w h e t h e r t h e U A R T i s r e a d y t o r e c e i v e d a t a . W h e n t h i s b i t i s l o w , t h e
U A R T i s r e a d y t o r e c e i v e d a t a . A r e s e t o p e r a t i o n s e t s t h i s s i g n a l t o
i t s i n a c t i v e ( h i g h ) s t a t e . L O O P M o d e o p e r a t i o n h o l d s t h i s s i g n a l i n
i t s i n a c t i v e s t a t e .
UART 1 Serial Input: Serial data input from the device pin to the
receive shift register.
®
• N o n - A u t o f l o w M o d e :
• A u t o f l o w M o d e :
• N o n - A u t o f l o w M o d e :
• A u t o f l o w M o d e :
4 1 3 8 0 8 a n d I n t e l
W h e n n o t i n A u t o f l o w M o d e , b i t [ 4 ] ( C T S ) o f t h e M o d e m S t a t u s
R e g i s t e r ( M S R ) i n d i c a t e s t h e s t a t e o f C T S # . B i t [ 4 ] i s t h e
c o m p l e m e n t o f t h e C T S # s i g n a l . B i t [ 0 ] ( D C T S ) o f t h e M o d e m
S t a t u s R e g i s t e r i n d i c a t e s w h e t h e r t h e C T S # i n p u t h a s c h a n g e d
s t a t e s i n c e t h e p r e v i o u s r e a d i n g o f t h e M o d e m S t a t u s R e g i s t e r .
C T S # h a s n o e f f e c t o n t h e t r a n s m i t t e r . T h e u s e r c a n p r o g r a m
t h e U A R T t o i n t e r r u p t t h e p r o c e s s o r w h e n D C T S c h a n g e s s t a t e .
T h e p r o g r a m m e r c a n t h e n s t a l l t h e o u t g o i n g d a t a s t r e a m b y
s t a r v i n g t h e t r a n s m i t F I F O o r d i s a b l i n g t h e U A R T w i t h t h e I E R
r e g i s t e r .
I n A u t o f l o w M o d e , t h e U A R T t r a n s m i t c i r c u i t y c h e c k s t h e s t a t e o f
C T S # b e f o r e t r a n s m i t t i n g e a c h b y t e . W h e n C T S # i s h i g h , n o
d a t a i s t r a n s m i t t e d .
T h e R T S # o u t p u t s i g n a l c a n b e a s s e r t e d b y s e t t i n g b i t [ 1 ] ( R T S )
o f t h e M o d e m C o n t r o l R e g i s t e r t o 1 . T h e R T S b i t i s t h e
c o m p l e m e n t o f t h e R T S # s i g n a l .
R T S # i s a u t o m a t i c a l l y a s s e r t e d b y t h e a u t o f l o w c i r c u i t r y w h e n
t h e r e c e i v e b u f f e r e x c e e d s i t s p r o g r a m m e d t h r e s h o l d . I t i s
d e a s s e r t e d w h e n e n o u g h b y t e s a r e r e m o v e d f r o m t h e b u f f e r t o
l o w e r t h e d a t a l e v e l b a c k t o t h e t h r e s h o l d .
W h e n U A R T t r a n s m i s s i o n i s s t a l l e d b y d i s a b l i n g t h e U A R T ,
t h e u s e r d o e s n o t r e c e i v e a n M S R i n t e r r u p t w h e n C T S #
r e a s s e r t s . T h i s i s b e c a u s e d i s a b l i n g t h e U A R T a l s o d i s a b l e s
i n t e r r u p t s . T o w o r k a r o u n d t h i s , t h e u s e r c a n u s e A u t o C T S
i n A u t o f l o w M o d e , o r p r o g r a m t h e C T S # p i n t o i n t e r r u p t .
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4 1 3 8 1 2 S A S / S A T A I / O C o n t r o l l e r s i n T P E R M o d e
C T S #
D e s c r i p t i o n
signal is a modem-status input whose
C T S #
D a t a s h e e t
high, the
2 5