A quick question with LTC3780

I've searched that LTC3780 has three modes, two of which are the Constant Voltage and Constant Current. Suppose I want to use this module to charge NiMh batteries with constant current. How can I enter the constant current mode? Do I need to MAX out the voltage-potentiometer?

You need to read the datasheet
http://cds.linear.com/docs/en/datasheet/3780ff.pdf