@User: Connect to any pad through the "PAD_A_ESD_0_H" or "PAD_A_ESD_1_H" ports. The startup program for the SoC will then need to shut off both digital input and digital output, leaving the pad at high impedence so that you can apply an analog voltage. That should be good for an input range of 0 to VDDA (typically 3.3V but can be as high as 5.5V).