2024-03-11 02:48 AM
The notion of group priority and subpriority is not very clear in the STM32H7 programming manual.
First the manual states that:
According to the value of the register AIRCR (0xFA050000) the splitting between group priority and subpriority for interrupts should be:
But then in the NVIC description I read:
What is "n" ? At first I thought that it was the number of "xxx" in table 56 but I noticed that I could only write the 4 least significant bits in IPR registers , which means n=4 ?
How to set group and subpriority priorities if only 4 bits can be written in IPR registers ?
Solved! Go to Solution.
2024-03-11 04:17 AM - edited 2024-03-11 04:19 AM
Hello @Gpeti ,
here are some clarifications about interrupt prioritization :
ST micro-controllers implements 4 bits (MSB) from the 8 bits reserved for priority so only the marked region in the screen below (bits marked in green in the red rectangle) is valid for STM32.
BR
2024-03-11 04:17 AM - edited 2024-03-11 04:19 AM
Hello @Gpeti ,
here are some clarifications about interrupt prioritization :
ST micro-controllers implements 4 bits (MSB) from the 8 bits reserved for priority so only the marked region in the screen below (bits marked in green in the red rectangle) is valid for STM32.
BR
2024-03-11 04:41 AM - edited 2024-03-11 04:43 AM
Thank you, I was missing this table. Would be nice to put it in the reference manual or programming manual
It's a bit weird that the default value of PRIGROUP in AIRCR is not a valid value (even if I understood that it works fine with the 4 bits being the group priority)
Regards