[En-Nut-Discussion] Courious problem with NutEventWait()

Ole Reinhardt ole.reinhardt at embedded-it.de
Tue Apr 5 17:33:43 CEST 2011

Hi Ulrich,

indeed a quite strange problem. But google gave some interesting hints:


It might be a problem in the implementation of the scheduler as bit0 of
the target address always have to be set to one on a branch on the CM3
architecture (if I understood the above article correcly).

Might there be some special cases where your scheduler may fail?

Can you track down the exception to a single instruction? AFAIK you
should be able to read out the pc value of the place where the
instruction occured (sorry, I just does not have by hand where this
value is stored on a CM3, in the LR register?)

Also other error sources might be possible:

"Usage Fault: detects execution of undefined instructions, unaligned
memory access for load/store multiple. When enabled, divide-by-zero and
other unaligned memory accesses are also detected.




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