S32K344 PreemptionPriority config

[liyongfeng]

The S32K344  dafault  AIRCR.PRIGROUP = 000 ,  This means that the GroupPriorities = 128, subPriorties=2.  Now i use PIT0 and PIT1 , If I need  PIT1  PreemptionPriority  highter to PIT0 . How to configure the registers of S32NVIC.NVICIPn? What is the mapping  between the S32NVIC.NVICIPn to the PreemptionPriority and SubPriorties?

[danielmartynek]

Hi @liyongfeng,

The IRQ priority width is 4 on this device, so there are 16 priority levels.

Do you need to use subpriorities?

If you just need PIT1 to able to preempt PIT0, just set the priority number of PIT0 higher than PIT0.

For example, PIT0 priority number = 1, PIT1 priority number = 0.

And leave AIRCR.PRIGROUP = 0b000

Regards,

Daniel 

[liyongfeng]

thanks.  

I don't understand how PreemptionPriority and subPriorties are implemented in S32K344?   

Or does the S32K344 only have 16 PreemptionPriority?

[danielmartynek · Accepted solution]

Hi @liyongfeng,

I'm sorry for the delay, I was out of office for a few days.

I believe it is explained in the thread below, the implementation is very similar on S32K1xx.

https://community.nxp.com/t5/S32K/pre-emption-priority-and-subpriority/m-p/686798

BR, Daniel