The System Monitor provides access to 17 external analog channels. The VP/VN are dedicated external analog pins, while the SYSMON can also accommodate up to 16 external analog pins on multiplexed I/O and high-density I/O (PS/PMC MIO and HDIO) pins. These 16 external analog pins are referred to as auxiliary input pins (VAUXP[15:0]/VAUXN[15:0]) and connect the ADC to external pins on the device through a set of MIO pins or the HDIO pins (not present in all devices).
For an external auxiliary channel, pin selection is extremely flexible and can leverage pins in the same bank or spread out amounts on multiple PS/PMC MIO and HDIO banks (when applicable). Any two pins within a capable bank can be paired for a given external auxiliary channel and can operate in unipolar mode or bipolar mode. An auxiliary channel can share VAUXN pins or can use the bank's ground as the VAUXN pin (for unipolar sampling only). The Control, Interface, and Processing IP in the Vivado tool is used to assign auxiliary external analog inputs and ensure that I/O pins used by the SYSMON are prohibited from being used as user I/O in the Vivado tool. For a description of the external analog input's equivalent analog circuit, see the Analog Input Description section.