TMS320F280039C: Exception handling in F280039C

Hi,

Please have a look at this thread - (+) TMS320F280039C: What the TI CPU does when a divide-by-zero occurs - C2000 microcontrollers forum - C2000︎ microcontrollers - TI E2E support forums

Thanks

Aswin

Hello Ito,

Apologies, it looks like the thread Aswin cited has a link to an internal forum post, this is why it's not viewable.

To help answer your question, can you clarify what sort of exception are you asking about specifically? The three examples you gave differ fairly significantly, the second one being related to security and the first/third being related to general CPU execution, and for this reason they are handled differently.

For the divide-by-zero, you can refer to this post: https://e2e.ti.com/support/microcontrollers/c2000-microcontrollers-group/c2000/f/c2000-microcontrollers-forum/21596/divide-by-zero-what-happens. The link cited is no longer available, but the post describes what happens. One method of verifying this is simply by putting a divide by zero within your code. It shouldn't break the hardware certainly, you can try to determine what happens in your application by adding this in manually. From what I have tested on the F28004x board I have available to me, dividing by 0 sets the variable to 'infinity' (for the uint32_t variable I used this meant 0xFFFFFFFF).

For an undefined instruction (i.e. 0x0), this will cause an ITRAP instruction to be executed, which causes the illegal instruction handler to be called. This function has an infinite loop and will prevent the program from continuing (this does not cause a reset from what I've experienced, but I have not had the watchdog enabled for my projects).