I followed the configuration steps in the operation manual to configure some GPIO pins of the S32K328 to maintain a high level in standby mode, but it failed. Below is my configuration process. I did not perform the fourth step recommended in the manual. Does this have an impact? I have performed similar configurations on the S32K312 before without any errors. My understanding is that, since I did not disable the pin keep function after reset, even if I configure the GPIO pins to output a low level after wake‑up, the output pin level should still maintain the high level that was set before entering standby mode. Currently, in actual measurements, the several GPIO pins configured in both standby mode and run mode have remained at a low level.
Hi @hhggll23,
I did not perform the fourth step recommended in the manual. Does this have an impact?
Yes, it does. If you enable Pad Keeping before going to standby mode (write DCM_GPR->DCMRWF1[STANDBY_IO_CONFIG] = 0. Which is default register value no matter PKE of SIUL2 is set or not), but you did not disable it after wakeup, the SIUL2 module cannot be initialized again. If you don’t need the Pad Keeping function while the MCU needs to go to standby mode and wakeup, you need to write 1 to this bit anywhere and leave it alone.
This is done through the Power_Ip_Init() API:
Now, I/O pins retain their last set states in run mode during standby mode, regardless of Pad Keeping configuration.
Since S32K3 will always perform a reset sequence after waking up, and since SIUL2 module resets the GPIO pads to its default state on a functional reset, pad keeping ensures that the pin can retain its state from wakeup until user unlock it.
Are you trying to set all of the pins shown in the image to HIGH on Standby? Are all of them going LOW upon entering Standby? Or when exiting?
Best regards,
Julián
Thank you very much for your reply. I rechecked the program and found that after pulling the pins high before standby, an unintended routine ran that re‑initialized all GPIO pins, which caused the pins to remain at a low level during standby. After the modification, the GPIO pin levels have been successfully pulled high in standby mode. Now a new issue has arisen: after the GPIO pins are pulled high in standby mode, the standby current seems to have increased. Currently, under standby conditions, the quiescent current of the controller is about 3 mA with a 24 V supply. After troubleshooting other circuits, I suspect that the S32K328 consumes most of this current. At 24 V, 3 mA corresponds to about 14.4 mA when converted to the controller's 5 V supply. I have pulled high 8 GPIO pins in standby mode. Is this standby current normal? To address this issue, can I configure the GPIO pins of the S32K328 as high‑impedance in standby mode, so that an external pull‑up resistor can maintain the high level on the pins during standby?