Quatech DS-1000, Руководство пользователя

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I I I F . L I N E S T A T U S R E G I S T E R (continued)
Bits BI, FE, PE, and OE are the sources of
r e c e i v e r l i n e s t a t u s i n t e r r u p t s . T h e b i t s
a r e r e s e t b y r e a d i n g t h e l i n e s t a t u s
r e g i s t e r . I n F I F O m o d e , t h e s e b i t s a r e
associated with a specific character in the
F I F O a n d t h e e x c e p t i o n i s r e v e a l e d o n l y
w h e n t h a t c h a r a c t e r r e a c h e s t h e t o p o f t h e
FIFO.
BI - Break Interrupt:
I n d i c a t e s t h e r e c e i v e d a t a i n p u t h a s b e e n i n t h e
s p a c i n g s t a t e ( l o g i c 0 ) f o r l o n g e r t h a n o n e f u l l w o r d
transmission time.
FIFO mode:
O n l y o n e z e r o c h a r a c t e r i s l o a d e d i n t o t h e F I F O a n d
t r a n s f e r s a r e d i s a b l e d u n t i l S I N g o e s t o t h e m a r k
state (logic 1) and a valid start bit is received.
FE - Framing Error:
I n d i c a t e s t h e r e c e i v e d c h a r a c t e r h a d a n i n v a l i d s t o p
b i t . T h e s t o p b i t f o l l o w i n g t h e l a s t d a t a o r p a r i t y
bit was a 0 bit (spacing level).
PE - Parity Error:
I n d i c a t e s t h a t t h e r e c e i v e d d a t a d o e s n o t h a v e t h e
correct parity.
OE - Overrun Error:
I n d i c a t e s t h e r e c e i v e b u f f e r w a s n o t r e a d b e f o r e t h e
n e x t c h a r a c t e r w a s r e c e i v e d a n d t h e c h a r a c t e r i s
destroyed.
FIFO mode:
I n d i c a t e s t h e F I F O i s f u l l a n d a n o t h e r c h a r a c t e r h a s
b e e n s h i f t e d i n . T h e c h a r a c t e r i n t h e s h i f t r e g i s t e r
is destroyed but is not transferred to the FIFO.
DR - Data ready:
I n d i c a t e s d a t a i s p r e s e n t i n t h e r e c e i v e b u f f e r o r
F I F O . D R i s r e s e t b y r e a d i n g t h e r e c e i v e b u f f e r
register or receiver FIFO.
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