Details:

The VIM will not always interrupt the currently active interrupt when a higher priority interrupt arrives immediately afterwards. In these cases, the higher priority interrupt will only be taken after the completion of the current lower priority interrupt or when an even higher priority interrupt arrives. The impact of this issue is higher than expected interrupt latency for the high priority interrupt. Both Vector Interface (VIC) servicing and MMR Interface servicing modes of VIM are affected.

Workaround(s):

This is a problem which affects applications which are latency critical and wants pre-empting of low priority interrupts with higher priority interrupts. If the application is not latency critical, then the behavior may be acceptable (the high priority interrupt will be eventually taken after the low priority interrupt completes).

Alternatively, user can implement a completely SW managed interrupt servicing scheme, where every ISR (Interrupt Service Routine) shall check for the presence of an active higher priority interrupt (by reading Interrupt Raw Status registers in VIM) and jumping to the ISR corresponding to that interrupt.