Interrupt priority grouping on stm32f1xx series

[amomum]

Posted on April 30, 2015 at 12:12

In programming manual (PM0056) in the description of ''Application interrupt and reset control register (SCB_AIRCR)'' two things are written:

1) Bits 10,9 and 8 defines PRIGROUP - they determine the split of group priority from subpriority. Later, in the table 45, all correct values of these bits are listed and they are:

0b011, 0b100, 0b101, 0b110 and 0b111.

2) Reset value of this register is said to be 0xFA05 0000 - so after reset PRIGROUP bits are all zero. And that value is not listed in the table, so it must be incorrect.

Please tell me, am I correct? And if I am, how exactly will subpriorities work after reset?

#stm32 #interrupts #preemption

[Amel NASRI]

Posted on May 14, 2015 at 18:32

Hi Roman,

After reset, the behavior will be the same as when 4 bits are used for group priority and 0 bit for subpriority. It means the equivalent of PRIGROUP = 011.

Best Regards

-Mayla-

[amomum]

Posted on May 15, 2015 at 10:55

Thanks, Myala!