CCS/TMS320F28335: Illegal ISR when using DELAY_US routine in TImer isr

Hello

The usDelay function is being placed in RAM before usage? You're satisfied the usage instructions as detailed in DSP2833x_usDelay.asm?

Best regards
Chris

Hey Chris, I didn't understand the function being placed in the RAM before usage. When we load the program into the RAM,the function has to be there already, we don't have to place it and I'm just trying to give 1 micro-second delay which i think follows the usage instructions.


Thank you!

Hello

Ok, it you're loading your whole app to RAM, than that should be fine. This will give ILLEGAL ISR if trying to run this function from flash and not copied to RAM before hand.

Are you passing in a constant value? You don't want to pass in a variable.
Does this occur if you make the delay larger?

Best regards
Chris

Hi Chris,

I have been passing a constant value and not a variable. I tried giving delays in seconds as well but then it won't work. I am running the code in flash but i have included all the libraries so that none of the function definition is left out.

Hello

To confirm, the delay function is tied to the ramfuncs section and you're running the memcpy in your code to make sure that function runs from RAM?
What if you call the delay function outside of the ISR, any issues?

Best regards
Chris

Hi,

Yes and if I call the Delay function outside of the ISR, there are no issues. It works just fine.

Regards,
Akhil

Akhil

Can post a screenshot of the disassembly for your ISR that includes the call to the delay function?

EDIT: Also include your .MAP file

Best regards
Chris