S32K144 PTE4 configuration when work at VLPS mode?

[hansonhe]

Dear, We test S32K144 low power mode at VLPS mode, when config all GPIO as disable status, enter into VLPS command, S32K will wakeup from VLPS mode immediately. We check again, find it is due to PTE4 pin problem, this pin also could work as CAN receive function.

We test as below:

1. config PTE4 as disable status, S32K will be wakeup immediately when enter into VLPS.

2. config PTE4 as disable status, S32K will continue to sleep when PTE4 pull up to high level.

3. If we do not config PTE4 as disable status, S32K will continue to sleep. What is the feature about PTE4? Why it will make above result? Thanks.

[hansonhe]

Dear, we have find reason as below,

Customer config PTE4 as CAN function, they do FlexCAN_DRV_init, and they set PTE4 as ALT0 for disable status,

as ALT1 for GPIO status, find it could not enter into VLPS.

We help to revise their code,

Add FlexCAN_DRV_Deinit before enter inter VLPS, the VLPS work normally.

And then we config PTE4 as GPIO status, it could wakeup VLPS when falling edge interrupt occur.

So if S32K need enter into VLPS, whether we need disable some of the peripherial function if we enable before?

As we known, CAN function is OFF status in VLPS mode.

[lukaszadrapa]

Hi,

The FlexCAN module is reused from MPC56xx family. I can remember there was this problem (answer sent to another customer in the past):

“One of the reasons that I found out could be the status of crystal (if it is running or not) and status of FlexCAN and Flexray peripherals. Let me explain:

If any mode transition enabled crystal (XOSCON bit in mode configuration registers) and if we want to turn off the crystal again then we have to ensure the Flexray module and all FlexCANs are frozen by means of Peripheral Control Register (ME_PCTL).

If the peripherals (Flexray+FlexCANs) are active and if we are going to turn off the crystal then the mode transition will NOT pass. It is necessary to frozen the peripherals by ME_PCTLx and then turn off the crystal.

Status of peripherals can be checked in ME_PS0 register.”

It looks like it works in the same way on S32K144.

Regards,

Lukas