S32K312 - Can I read LPCMP wakeup value ?

[ssean]

Hello.

I use LPCMP module for wakeup from standby state.

https://community.nxp.com/t5/S32K/S32K312-About-Low-power-and-ADC-input/m-p/1642167

Can I read LPCMP last compared value when MCU wakeup ?

For example.

Switch A: Input 1.0 V

Switch B: Input 2.0 V

A & B connected same LPCMP channel.

LPCMP wakeup input voltage under 3V.

How can I read which switch pushed ?

Best Regards

[Robin_Shen]

Hi

Sorry, if you connect two analog signals to the same LPCMP channel, won't they affect each other? Or can you ensure that only one of the signals is connected to that LPCMP channel at the same time?

It is recommended to connect to two different LPCMP channels, or modify the Integrated 8-bit DAC Voltage Level to distinguish 1.0v or 2.0v after wakeup.

Best Regards,
Robin
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[ssean]

@Robin_Shen 

Hi.

LPCMP channel connected only one analog signal.

But that signal input value(voltage) has two different value according to system condition.

(Voltage divider switch)

How can I distinguish LPCMP last input value?

Is LPCMP module memory last value in register?

Best Regards,

Sean

[Robin_Shen · Accepted solution]

I don't find a register of LPCMP is able to store the analog value. After wakeup, set the DAC Output Voltage to 1.5V and re-compare the input signal, distinguish it was 1.0v or 2.0v.

[ssean]

@Robin_Shen 

Thank you for advise.

I'll test it.