XR68C681J-F Datasheet, PDF (42/75 Pages) Exar Corporation – CMOS Dual Channel UART(DUART)

XR68C681
Output Port
,
,
,
,1
,=
,6
,/
,@
Alternate Function(s)
RTSA: C% $   + '    84  (%  (% '( : +    + '
( 
RTSB: C% $   + '   * 84  (%  (% '( : +    + '
( 
TXCA_16X Output:
  /5  %(
'3 4
TXCA_1X Output:
  5  %(
'3 
RXCA_1X: Output:
  5 '(
'3 
TXCB_1X Output:
  * 5  %(
'3 4
RXCB_1X Output:
  * 5 '(
'3 
C/T_1_RDY:  
 .( $&  +
. P Note: This output is an Open-Drain output
when used as the Counter/Timer Ready Output.
RXRDY/FFULL_A Output:
  '( $&. #   # $(' 84  (% (%   
(  +   5E. ::D + '( 
RXRDY/FFULL_B Output:
  * '( $&. #   # $(' 84  (% (%   
(  +   5E. ::D* + '( 
TXRDY_A Output:
   %( $& # $('  (% (%   (  +  
5ED + '( 
TXRDY_B Output:
  *  %( $& # $('  (% (%   (  +  
5ED* + '( 
Table 15. Listing of the Alternate Functions for the Output Port
 & +      '( % +   (%   ( %  %'$ & (( -   ( $    ,

  ( + +  (% -(% +%
Bit 7
OP7
 J ,M@N
 J 5E*
Bit 6
OP6
 J ,M/N
 J 5E
Bit 5
OP5
 J ,M6N
 J 5E.
::*
Bit 4
OP4
 J ,M=N
 J 5E.
::
Bit 3
Bit 2
OP3
 J ,M1N
 J
. P 
 J 5
*5
 J 5
* 5
Bit 1
Bit 0
OP2
 J ,MN
 J 5
/5
 J 5
5
 J 5
5
Table 16. Output Port Configuration Register - OPCR
Note:
OPCR only addresses the alternate functions for output port pins, OP7 - OP2. OP0 and OP1 assume their RTS roles if either
MR1n[7] = 1 or MR2n[5] = 1. Setting those mode register bits enables the RTS function. Otherwise, these two ports will only be
general purpose output ports.
G. SERIAL CHANNELS A and B
2' %( '   +     '(%% 
+$! %& '  % '(  $  %(  
 '  % ' ( $ $ & %'  ( ( -
+C '& +   *0"  
."   !  ''3 %
 % ( - $ *%($%    $ (
 ('   '(  $  %( + ' '  
 ( $ $ &"     '  ' +(-$ 
 ( (% ( - $%"  ('  %+ +
'  $  $(- %('%" %  % (  3 
$ %$ + ($ ('( %
 
=