XR68C681 Datasheet, PDF (15/75 Pages) Exar Corporation – CMOS Dual Channel UART (DUART)

XR68C681
Bit 7
















Bit 6
















Bit 5
















Bit 4
















Description
Null Command:
Reset MRn Pointer:
%%   '  .%  (   (    
Reset Receiver: %%   ( $(($ '   '( % (+  $ % %
 ($   '( (% $(%$  $   #  (% +% $
Reset Transmitte4 %%   ( $(($ '    %( % (+  $ %
$  ($   5  (% +'$   (- 
Reset Error Status:
%   '($ *3 *" ,(& 2 ,2" ( -
2  2  $  2 2 %% (%" M@41N
'(+('&" (+    $" +  (' '   (% %  H*'3I  $"
 (% ' $ ( %    +   '(  ( $('% (   %% -(%
#   '3  $"  ' (   ,2" 2" 2  * ''%"  (%  ( ' 
(    +--$ (   '   %% -(%"  (  (% ' $ (% (%%$
#+   2 $" +  (' '   (% %  H
'I 2 $"    
'  % +   % -(% + ,2" 2  $ *  +'$   ' ' &
' ' %(' #   H
'I 2 $"   % +  % ( $('% (%
%$  &    ' '   (%     +   9
  2 ( $(' (% &% +--$ %  H*'3I 2 $ ( $('"  $ C(%
 (% ' $   %
Reset Break Change Interrupt:
%   '  .% 3 '  - (  %%
(
Start Break: '%   5      %( %   $  %
 3 #+    %( (% &"   % +   3 &  $&$   
( (% #+    %( (% '("   3 -( %      %(%%( +
 % ' '% (   9 (% '$" (G" 52, %   +  
3 ( -( 
Stop Break:   5 (  ( - (- ( (  ( (% 5 ( ( (-
+   ( ( +   ! ' '" (+  &" (%  %($
Set Rx BRG Select Extend Bit: %   '  .% H'( *0 ' 2! $
*(I  HI - !J
Clear Rx BRG Select Extend Bit:
%   '  .% H'( *0 '
2! $ *(I - !J
Set Tx BRG Select Extend Bit: %   '  .% H %( *0 ' 2!
 $ *(I  HI
Clear Tx BRG Select Extend Bit:
%     '  .% H %( *0 
' 2! $ *(I  HI
Set Standby Mode (Channel A): A   (% ' $ (% ( 3$ (   '  
' $ -(%"  (% $ + ' +    %(%" '(%"

 .(  $ $$((  '('(%  '     (   % $&  
 $ ,%     (% ' $ ++'%   ( +    (
' ( 8 ( (% %$ &  $ %  & ( 3( -   H2

#;2 2I ' $
Set Active Mode (Channel A): A   (% ' $ (% ( 3$ (   '  
' $ -(%"     (% $ +   % $& $  $ %%
 ( 
Reserved
Reserved
Table 3. Miscellaneous Commands, Upper Nibble of all Command Registers, Unless Otherwise Specified.
 
6