FX3 and FIQ interrupt

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
Anonymous
Not applicable

Hi all,

   

In short: in which cases can be a FIQ interrupt raised and __CyU3PFiqHandler called?

   

Today I observe strange firmware freeze. I connect JTAG to the my board and stop CPU. At the stack trace I see that code execution point is located in the __CyU3PFiqHandler handler. I looked to the it implementation in the cyu3entry_gcc.S and found that it is a simple infinity loop. Also next comment confuse me:

   

"The following exceptions are not expected to occur on this setup.
The handlers are left in place for completion."

   

And __CyU3PFiqHandler implementation:

   
.global __CyU3PFiqHandler __CyU3PFiqHandler:     b __CyU3PFiqHandler
   

If I correctly understand, if Fast interrupt is happens, then all IRQ and FIQ interrupts is masked. In SDK code the FIQ interrupt handler never finishes, therefore system totally freezed.

   

And I don't understand what is cause of the FIQ interrupt.

   

Thanks for any help.

0 Likes
1 Reply