XR88C681 Datasheet, PDF (62/99 Pages) Exar Corporation – CMOS DUAL CHANNEL UART (DUART)

XR88C681
Input Port
#,
#,
#,
#,1
#,<
#,6
Alternate Function(s)
Approach to Program Alternate Functions
CTSA4
   $ 
 (  +
  
74  (% (  (% '( 9" +  
 + '(
#, '  -$  + '( %   

(  & %( -  N<O J    $($
$(%'%%(   (% + '( " % % Section
G.3.
CTSB4
   $ 
 (  +
  * #, '  -$  + '( %   
*
74  (% (  (% '( 9 +  
 + '( (  & %( - *N<O J    $($
$(%'%%(   (% + '( " % % Section G.3.
CT_EX4
 .( 2! 
'3 # 
RXCB4 2! 
'3 (  + '(

  *
#, '  -$  + '( %   ! 
''3 (  +  
 .( & %( -

N/4<O J N" " O    $($ $(%'%
%( (    ++' +  (% '( % % Section
D.2
#, ' %  -$  + '( %  
!  ''3 (  +   '( +
  *
& %( -
*N>4<O J N" " " O +   /5

'3" 
*N>4<O J N" " " O +   5
'3
TXCA: 2! 
'3 (  +  %(

 
#,1 '  -$  + '( %   ! 
''3 (  +    %( +
  & %
( -
 N14O J N" " " O +   /5
'3" 

 N14O J N" " " O +   5
'3
RXCA4 2! 
'3 (  + '(

 
#,< '  -$  + '( %   ! 
''3 (  +   '( +
  & %( -

 N>4<O J N" " " O +   /5
'3" 

 N>4<O J N" " " O +   5
'3
TXCB4 2! 
'3 (  +  %(

  *
#,6 '  -$  + '( %   ! 
''3 (  +    %( +
  * & %
( -
*N14O J N" " " O +   /5
'3" 

*N14O J N" " " O +   5
'3
Table 21. Listing of Alternate Function for the Input Port
E.2 Input Port Configuration Registers (IPCR)

 - + % $'%  ($$ + (  ( % #,  - #,1  % ( %  %$ &   1=<38I 
+   *0 <3% ! / (-    (-  %((   % (  %( -  %  ''3 ($%
!(& 6• % ( -      '% $( - ( (   (   '  - -(% #,
 (  %"
 - ( &  % &  '  - + % % %  % 6• %   ( + +   #,
 +%   %% (% (  
#,
 #,
N>4<O  '$     -(% (% $ &  
, & '  - + % ' %  -$ 
-   (  (   C#  ,
 - + D ( 
Bit 7
Delta IP3
 J 7
 J G%
Bit 6
Delta IP2
 J 7
 J G%
Bit 5
Delta IP1
 J 7
 J G%
Bit 4
Delta IP0
 J 7
 J G%
Bit 3
IP3
 J 9
 J 8(-
Bit 2
IP2
 J 9
 J 8(-
Bit 1
IP1
 J 9
 J 8(-
Bit 0
IP0
 J 9
 J 8(-
 
Table 22. Input Port Configuration Register - IPCR
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