Hello, I developed an emmbedded application for a C167CR-LM. In this application I've some very big data structures stored in internal RAM (IDATA) and some dynamic list managed using malloc and free. For dynamic allocation I define the pool:
unsigned char far equivalence_pool[0x4000]; init_mempool (equivalence_pool, sizeof (equivalence_pool));
In my application there is a IRQ routine on a Timer T6 with a period of 0.5 ms.
In some situations the ILLOPA exception is trapped an the application crashes. It generally happens when many digital input (linked to port P2 pins) are active together.
I tried to increase the user stack with no effect.
Adding 2 calls to printf in the IRQ routine, ILLOPA is not generated.
Have you some suggestions for help me how to investigate this problem?
Testing with Mon166 the trap routines are not available, and using Simulator is too complex cause the hardware and input sequences to generate.
Thanks, Marco
Small correction. Just looked it up: ILLOPA is 'Illegal Word Operand Access.' It happens when a word access is attempted at an odd address. Look out for unaligned pointers. The method I suggested should allow you to pinpoint the exact line of source code and the offending unaligned pointer.