RE: Access denied

 
Alan,
 
 
Thank you verify much for your help!
 
Alas, this only confirm my fears: we left RSTCONF unconnected on our new board :-(( The old one had an external pull-up resistor to +3.3V and it would have been easy to drive it low. Next rework of this new card will include a pull-up...


Best regards.


Jean-Christophe MATHAE

CIRTEM
http://www.cirtem.com

bâtiment Pointe Bleue
20, voie l'Occitane
BP661
31319 LABEGE cedex
France

________________________________

De : MPC500@... [mailto:MPC500@...] De la part de Dobbin Allan
Envoyé : vendredi 14 novembre 2008 16:16
À : MPC500@...
Objet : RE: [MPC500] Access denied



Reset configuration comes from block 0 shadow flash - if certain bits in the shadow reset config word is programmed to 0, BDM can be locked out. To get the part back, drive RSTCONF LOW to override the shadow config. The reset config is now sampled from the data bus and chances are that is all you will have to do. If you have certain DATA pins held low, you may have to pull those up. Its been a while since I worked on that part and I can't remember exactly what the relevant bits are, but this is likely enough to get you by.

Assuming BDM now works, erase the shadow and you should be able to use the part again as normal.

- Allan

________________________________

From: MPC500@... <mailto:MPC500%40yahoogroups.com>  [mailto:MPC500@... <mailto:MPC500%40yahoogroups.com> ] On Behalf Of Jean-Christophe MATHAE
Sent: Friday, November 14, 2008 4:38 AM
To: MPC500@... <mailto:MPC500%40yahoogroups.com>
Subject: [MPC500] Access denied

Hello,

While trying to use the General Market CMF Driver for MPC555, I think that I have turned a MPC555 chip into a useless bit of silicon...

Is this possible? Could a wrong shadow information in Flash make the chip unresponsive to the BDM?

Best regards.

Jean-Christophe MATHAE

CIRTEM
http://www.cirtem.com <http://www.cirtem.com>  <http://www.cirtem.com <http://www.cirtem.com> >

bâtiment Pointe Bleue
20, voie l'Occitane
BP661
31319 LABEGE cedex
France

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