Interrupt priority question

Hi,

It's about the STM32F103 uC.

According the NVIC datasheet as I understand:
- all uninitialized interrupts have their fixed default interrupt sequence number
- by default initially all interrupts get priority number 0 (meaning highest priority)
- if two uninitialized interrupts occur at the same time then the one with the lowest priority number is executed first
- interrupts can be initialized by assigning them to a group (3,4,5,6,7) and to a subgroup within

With initialized/uninitialized is ment connected to a group or not.

My questions are:

- (I assume) interrupts assigned to a lower numbered group do pre-empty higher numbered group interrupts, is this correct?

- can a lower-priority uninitialized interrupt A get a higher priority than a higher-priority uninitialized interrupt B by connecting A to a group?

- if so: does A pre-empty B or does A wait for B to finish?

- will a higher-priority uninitialized interrupt pre-empty or wait for a lower-priority uninitialized interrupt?

I cannot figure this out from the NVIC pdf.

Thanks

Henk

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