I am using EWM module in S32K146,and have some question about EWM's application scenarios:
1. Why EWM_out can be de-assert only by forcing system reset?I am confused about what application scenarios need to be so extreme,have a specific example?Can I release EWM_out pin by reset EWM module,because I want to de-assert EWM_out pin by my software setting but not reset system.
2. If EWM_in is enable,the EWM_in looks like must input the same frequency square wave as the software refresh EWM frequency and EWM_in should de-assert when feed dog to avoid assert EWM_out. The picture below shows:
However,the EWM module clock source is LPO,so the EWM_in's clock source also should be it,otherwise, if LPO clock and EWM_in's clock is asynchronous,the EWM_out will assert in the future.
Hi,
1.
The EWM_out pin is used to place an external circuit into a safe mode.
It is a safety feature, the CTRL_EWMEN deaserts the EWM_OUT_b signal, but this bit is a write-once bit and therefore system reset is required to re-enable the EWM module.
2.
The EWM_in input allows an external circuit to control the assertion of the EWM_out signal.
If there is a fault in the external circuit, the EWM_in is asserted, otherwise it is deaserted.
Regards,
Daniel