Hi NXP Engineer:
I have a problem with Project from Example —— ADC_s32k144. In the code i see the function which (Convert chan 29, Vrefsh) at the end.

I want to know what is it used for?I can serach the note AN5413,and find some description and image like this

but also understand what this function is for doing.

I don't know why need to connects ch29.colud you tell me?
Thanks in advance.