Spectravideo MKI, Сервисное – Техническое руководство

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DLAB A
A A
REG I STER
0 0 0 0 Rece iver Bu f f e r ( read ) , T ransm i t t e r
Holding Reg i s ter ( wr i t e )
0 0 0 1 Inte rrupt Enab l e
X
0 1
0
I n t e r r upt Iden t i f i ca t i on ( read onl y )
X
0 1
1 Line Con t ro l
X
1
0 0 MODEM Con t ro l
X
1 0
1 L i ne S t atus
X
1 1 0 MODEr·f S ta t us
X
1
1 1 None
1
0 0
0 Divi sor Latch ( l e a s t s ignif icant by t e )
1 0 0 1
D iv i s o r La tch ( m o s t s i gn i f ica tnt byte )
Ma s t e r Re s e t ( MR ) , P in 3 5 : When h i g h , c l ears a l l t he reg i s t e r s ( except the
Rec e i ve r Buf f e r , Transm i t t e r H o l d i ng , and D iv i s o r Latches ) , and the con t r o l
o f the INS825� A l s o , the s t a t e o f va ri ous output s igna l s ( SOUT , INTRPT ,
OUT 1 , OUT 2 , RTS , DTR ) a re a f f e c ted by an a c t i ve MR input . ( Re f er t o tab l e
1 ) .
Rece i ve r C l ock ( RCLK) , P in 9 : Th i s input is
the
1 6x baud ra t e c l ock for the
rece i v e r s ec t i on o f the ch ip .
S e r ia l Input ( SI N ) , P in 1 0 : S e r i a l data input f rom the commun i c a t ions l ink
( pe r i phe r a l dev i ce , MODEM , or d a t a s et ) .
C l e a r t o Send ( CTS ) , P in 3 6 : The CTS s igna l i s a MODEM con t ro l func t ion inpu t
who s e c ond i t i on c an b e te s te d b y t he CPU by rea d ing b i t 4 ( CTS ) o f t h e MODEM
S ta t us Reg i s t e r . Bit 0 ( DCTS ) o f the MODEM S ta t us Reg i s t e r indic a t e s whe ther
t he CTS input h a s change d s ta te s ince t he p revious read ing o f t he MODEM S ta t u s
Reg i s t e r .
No t e : Whe neve r the CTS b i t o f the MODEM S ta t us Reg i s t e r changes s t a t e , an
inte rrupt is gene r a t e d if t he MODEM S t a t u s I n t e rrupt is enab l e d .
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