XR88C681CP Datasheet, PDF (71/99 Pages) Exar Corporation – CMOS DUAL CHANNEL UART (DUART)

XR88C681
Bit 7
Bit 6
Channel Mode
 J 7
 J  2' 
 J 9' 9
 J  9
Bit 5
Tx RTS
Control
 J 7
 J G%
Bit 4
CTS Enable
Tx
 J 7
 J G%
Bit 3
Bit 2
Bit 1
Bit Length
Bit 0
 J 6/1
 J /6
 J /==
1 J >6
< J =1
6 J =>6
/ J 1=
> J 
= J 6/1
 J /6
J /==
* J >6

J =1
 J =>6
2 J 1=
J 
Table 27. Mode Registers - MR2A, MR2B
MR1n[7] - Receiver Request to Send Control
$( (&"  E%   $ (% %%$  -$
& ( 3( -   C2 , , *#
 7D
 C
92  , , *#
 7D (  
(   8" (+  N>O J  (% %"  
  '( (  '     -( +  
  '(+('&" %( -  (% ( (   
'(  -  (+ (% 8 (% +  (% C+
' D ' (E (% %+ (  ( - '(
 2%
Figure 42 % %  $(-  (' (%%  
'(
 $ E% $ ' +(-(
$ + '( 
MR1n[6] - Receiver Interrupt Select
 (% ( %'% (    5G %% (    99
%% ( +   '     %$ %   '(( +
- ( -  #  E%   
," #NO +

   $ #N6O +
  *
MR1n[5] - Error Mode Select
 (% ( ' %   ( +     #  %% (%
,2" 2" '($ *3 +  
  #+  (% ( (% %
 CD"  (% (' '   (  (  
C
'D 2 $ #+  (% (% (% %  CD"  (%
(' '   (  (   C*'3D 2 $
#   ' ' $  % %% (% &  &   
' '   (% ' &     +   #  #  
'3 $"  % (% %    '( -('
 +   %% +  ' '% '( -     +  
#  %( '   % C22 2  D ' $
+  
  % (%%$
MR1n[4:3] - Parity Mode Select
#+ C( (&D  C+' (&D ( (% -$" 
(& ( (% $$$     %($ ' '%  $  
'( +%  (& ' '3  '($ ' '%
 Section H.2 + $%'(( + ( $
( 
MR1n[2] - Parity Type Select
 (% ( %'%   2;27 (& (+ CB#8 , #G
2D (% -$  $   % +   +'$ (&
( (+   C 
2 , #GD $ (% -$ #  
( $ ( %'%   % +   . +- (
 (% ( %  ++' (+ C7 , #GD (% %'$ (
 N<41O
MR1n[1:0] - Bits per Character Select
'%    + (%    %($  $ '($
(   $ +($ +   ' '  (% $%  ( '$
 " , #G"  $ , (%
Mode Register 2 (Channels A and B)
 + '
  (% ''%%$    
 H%
 ,(  ( %   "  (' ''% +  &
''%%   
 H%  -(% %E 
C$%D  C(%D   $%  '  -   '  %
+    ( 
 
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