S32K312 - Wakeup Reset

[ssean]

Hello.

I set WKPU and enter standby, trigger WKPU, wakeup. It works fine.

1. After wakeup, MCU jump to reset handler and start again code from main()?

2. Before standby, I set some register for MCU functions(Like ADC and SIUL2). After wakeup that register values was reset?

3. If I want to retain some data, is there available ram area? (Called retain ram or retention ram)

4. I found "standby ram" in reference manual. Is that retain data after standby and wakeup?

5. I can't find start address of standby ram. How can I find that?

6. What is diffrence between standby and fast standby?

Thank you.

[danielmartynek · Accepted solution]

Hello @ssean,

Please refer to the examples and the application note here:

https://community.nxp.com/t5/S32K-Knowledge-Base/S32K3-Low-Power-Management-AN-and-demos/ta-p/152772...

To your questions:

A1.

In normal standby exit mode, yes.

A2.

It needs to be initialized again

A3-4-5.

Yes, there is Standby RAM.

Please locate the linker file in this example:

S32K344_RTC_StandbyRAM_Wkup_S32DS_3_4_RTD_LLD_2_0.zip

A6.

If you look at the example above, there is

void Wkup_FastWkupBootAddress(void)

In the Fast standby exit mode, the execution starts there, and at the end of the function, it branches to the Reset_Handler().

Regards,

Daniel

[ssean]

@danielmartynek 

I understood. Thank you!