S32K中的主题 Re: S32K118 PIN

S32K118 PIN

wenfengyao — Mon, 28 Aug 2023 09:22:02 GMT

We need to input the external high-low level signal to the 18 pin of the MCU in series with a diode. At the beginning, the pin is in the default state without configuration, and only the external interrupt is used. In this case, the MCU pin detected at low level has a voltage of 800 or 900mV; When this pin is configured to the input (floating) state, the detected MCU pin has a voltage of about 0V at low voltage.

Our software colleagues believe that the external interrupt input and the configuration pin input (floating) should be in a high resistance state, but the measured results are not the same, may I ask the specific difference between the two internal circuits? What causes the low level input to have a voltage difference?

The part number is FS32K118LAT0MLFT

Re: S32K118 PIN

danielmartynek — Thu, 31 Aug 2023 07:16:50 GMT

Hi @wenfengyao,

It should be in HIGH-Z and the pin should read 0V in this case unless there is the internal pull-up enabled - which would explain the 900mV at the anode.

The pullup is enabled on PTC5 by default, for example.

Which pin do you use?

What is the usecase here?

Regards,

Daniel

Re: S32K118 PIN

wenfengyao — Thu, 31 Aug 2023 02:55:14 GMT

I just want to use PIN 18 PTC5 pin to do an interrupt input, so the default state of this pin is pull-up?

Re: S32K118 PIN

danielmartynek — Thu, 31 Aug 2023 07:28:44 GMT

Hi @wenfengyao,

PTC5 has internal pullup enabled by default out of reset.

Please refer to

S32K118 IO_Signal_Description_Input_Multiplexing.xlsx

IO SIgnal Table

Column S

Regards,

Daniel