XR88C681CP Datasheet, PDF (55/99 Pages) Exar Corporation – CMOS DUAL CHANNEL UART (DUART)

XR88C681
 $ '(% Table 17  $ Table 18 %    ( % (    '  % +  
%  $   ''3 %'
$(( -    %(%  $ '(%
Bit 7
Bit 6
Bit 5
'(
'3 '
 Table 18
Bit 4
Bit 3
Bit 2
Bit 1
 %(
'3 '
 Table 18
Bit 0
Table 17. Bit Format of the Clock Select Registers, CSRA and CSRB
Field
Bit Rate
CSR[7:4]
ACR[7] = 0
ACR[7] = 1
CSR[3:0]
X=0
X=1
X=0
X=1




6
>6
>6
6












1<6
1<6
1<6
1<6





6
6





1
1/
1
1/




/
<<:
/
<<:





==:

==:




6
6>/:

6>/:




<
6:
<
6:




<=
<=
<=
<=




>
=
=
>




/
/
/
/




1=<:
:
:
1=<:




(
(
(
(




2!   /5
2!   /5
2!   /5
2!   /5




2!   5
2!   5
2!   5
2!   5
Note: the b suffix denotes a binary expression. x = don’t care value.
Table 18. Bit Format of the Clock Select Registers, CSR[3:0] and CSR[7:4]
Please note that  = calls for the user to specify the
following parameters4

N>O    % %(- (+('  ( * +   !(
(&
  -(%
 5    2! $ (

N>O (%   * +   !((&
  -(%"  $
' %(&  -$ & (( - !!!!!!! 
!!!!!!!   
" ( $  %  '"
%'(&
X - The Select Extend bit
2'  %(  $ '(" ( (     % 
! $ (   '  %  '$ & (( -  
( $    '  H%
 $ -(%
 -  (% ( +( '  + $ ( Table 3
Table 19 %(I%  % ' $%"  $  ( ++'
   2! $ (%
 
66