RE: TouCAN register write

Joy, section 3 of the manual describes the difference between supervisor
and user modes.  These are controlled by MSR[PR] bit.  The value of PR
may change during an exception depending on your handling of MSR (rfi
writes MSR from SRR1).  If MSR[PR]=1, you cannot write the supervisor
registers you listed in your mail.  This mechanism is provided so that
operating systems can limit certain user mode accesses if required.

- Allan

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf
Of joydeep roy
Sent: Thursday, March 30, 2006 6:17 AM
To: MPC500 MPC500
Subject: [MPC500] TouCAN register write


Hi 
i am trying to write in the TouCAN registers but when
testing i ca see that not all the values are getting
written. Actually it looks like from location 0x307086
the values are getting written. The previous three location(TouCAN
starts from 0x307080 are not getting written. The memory mapping looks
ok cause the
CANCTRL0(0x307086) gets the intended value. i found
that the previous three registers have access mode in Supervisor mode
only. 
What diffrence does it make?  Is there any special way
to write to them in between a program like we have in
some DSPs.
Thanks,
Joy

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 


-----------------------------------------------------------
To learn more about Freescale Microcontrollers, please visit
http://www.freescale.com/mcu


 
Yahoo! Groups Links



 




-----------------------------------------------------------
To learn more about Freescale Microcontrollers, please visit
http://www.freescale.com/mcu


 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/MPC500/

<*> To unsubscribe from this group, send an email to:
    [email protected]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/