Tony Mouawad

MCF5475 - How do I know if the CPU is halted?

Discussion created by Tony Mouawad on Nov 8, 2007
Latest reply on Nov 13, 2007 by Dennis Shutt
I'm working with an MCF5475 running Linux v2.6.10 from the Freescale BSP.  I recently ran across information in the Coldfire Family Programmer's Reference Manual, Rev 3 in section 11.1.3 that states:
 
"Note that if a Coldfire processor encounters any fault while processing another fault, it immediately halts execution with a catastrophic fault-on-fault condition.  A reset is required to force the processor to exit this halted state."
 
I'm suspicious that we maybe encountering this catastrophic fault-on-fault condition but I am having trouble proving this.  I suspect this because on a very intermmitent basis, while I have my BDI2000 debugging tool plugged into the BDM port and when the system locks up, I halt the CPU using the debugger to investigate the registers and find that the registers have invalid values and that the BDI2000 loses communication with the CPU.  Under normal circumstances, I halt and resume the CPU without issue using the BDI2000. 
 
Is there a way to determine that the CPU experienced a catastrophic fault-on-fault condition by sticking a probe on one of the CPU pins or something along that line?
 
Regards,
Tony.

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