MMU malfunction?

[gpr]

Posted on July 27, 2005 at 09:20

MMU malfunction?

[gpr]

Posted on May 17, 2011 at 11:36

I have an application that uses the ST90R158 operates correctly about 90% of the time.

The only part of memory that is remapped is the internal ram, which is selected in DPR1 and is used for the stack and some initialized data. DPR0, DPR2, and DPR3 all point to the areas of memory within the normal 64K that would be addressed if the MMU didn't exist.

However, under some circumstances (usually during an increase in temperature) the unit changes it's accesses to the actual physical memory the program indicates, instead of the mapped memory. Since there is no ram there, the application fails. The program is still running, but it tend to fall into a loop where it's trying to increment values and can't.

Is there any way that the MMU can be disabled? I was under the impression that the MMU operated all of the time, but this is obviously not what's happening.

[kapil]

Posted on May 17, 2011 at 11:36

At what temperature this thing happen? and dose things come back to normal when temperature comes to normal temperature?

Reset the device at this high temperature and see if it works