FX3 and FIQ interrupt | Cypress Semiconductor
FX3 and FIQ interrupt
In short: in which cases a FIQ interrupt can be raised and __CyU3PFiqHandler is 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.