XR88C681CP Datasheet, PDF (14/99 Pages) Exar Corporation – CMOS DUAL CHANNEL UART (DUART)

XR88C681
Address (Hex)



1
<
6
/
>
=


*



2

Read Mode Registers
Register Name
Symbol
$ -(%"

 
 " 
% -(%"

 

%3$ # 
% -(%
#
! 8$( - -(%"

 
8
#  ,
 -
-(%
#,

#  %
#
-(%

 .( 
*& -(%



 .( 9

9
*& -(%
$ -(%"

  *
*" *
% -(%"

  *
*
22;2
! 8$( - -(%"

  *
#  ;'
-(%
#  ,
8*
#;
#,

 .(

 $

 .(

 $





Write Mode Registers
Register Name
Symbol
$ -(%"

 
 " 

'3 ' -(%"

 



 $ -(%


! 8$( - -(%"

 
!((&
 
-(%
#  %3 -(%
8


#

 .(
 *& -(%

 .( 9
*& -(%
$ -(%"

  *

'3 ' -(%"

  *

 $ -(%"

  *
! 8$( - -(%"

  *
#  ;'
-(%
 ,

 +(-( -(%
,  ,>
  , *(%

 $

  , *(%

 $



9
*" *

*

*
8*
#;
,

,*


,*

Table 1. DUART Port and Register Addressing
Note: The shaded blocks are not Read/Write registers but are rather “Address-Triggered” Commands.
Table 1 ( $('%   ' '   (% E($ (  $ -(%% %%'($ ( ' +  % $ -(%
(% (%  C$ -(%D (    (   ' (.%&%    22 '  (  (% C( ( - D
  '    -(% Please note that the suffix “n” is used at the end of many of the DUART registers symbols in
order to refer, generically, to either channels A or B 8"   '  % +    (  ( % (+ +   $$%%
+    -(%    +    -(%" ($(& +( -  & $  B( ''%%     -(%
   (  ( ' (   C(  D    -(%  (  $ % ''%   (  C22 
,#72D ' $ %  ( 3$   C22  ,#72D ' $ '  (%%$ & (( -  
( $    ( '  H%
 $ -(%  +"  $ -(%%" ( (  -(
 
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