I have some concerns regarding FS32K148 EWM Module:
[Reference: In RM there is a mentioning about having a pull down for EWM_Out_b signal ( Page 475).
“EWM_OUT_b pad must be in pull down state when EWM functionality is used and when EWM is under Reset.”
“The EWM_OUT_b is asserted after any reset by the virtue of the external pull-down mechanism on the EWM_OUT_b signal. Then, to deassert the EWM_OUT_b signal, set EWMEN bit in the CTRL register to enable the EWM” ]
The redundant watchdog EWM does not reset the MCU.
To reset the MCU, you need either the internal WDOG module or an external one like an SBC.
Adding an external pull-down resistor is the only way to ensure the EWM_OUT_b pin is LOW during MCU reset.
Because the EWM_OUT_b is an alternative function of some pins like PTA2.
Please have a look at the S32K148 IO_Signal_Description_Input_Multiplexing.xlsx file that is attached to the RM.
By default (out of reset), PTA2 is connected to ADC1 module, channel 0.
Therefore, whenever the MCU reset, the PTA2 pin becomes an ADC input until it is changed by the SW (routed to EWM, EWM enabled).