I am using Cortex M4 processor with Keil compiler with FreeRTOS and i notice that occasionally code is crashing in start up file ( attached is the snapshot of the point where code gets to when i stop controller).
Basically the system is a simple data acquisition board that has various sensor data collected in an FPGA. FPGA then sends a bulk of data-stream to my microcontroller on interrupts.
this data is stored on to external NAND flash memory (parallel type).
Using stack window , I see that the code always gets into an ‘UNKNOWN AREA’ in ISR. This ISR is called during the time when I’m writing data into the NAND flash. I’m certain that the micro-controller gets interrupts during the data-writing process.
I am unable to understand why would the code specifically go to the region that I have highlighted in the attachment.
Any help would be appreciated – I have spent weeks trying to resolve this problem.