The Analog Channel Select (CHS) bits determine which channel is connected to the
Sample-and-Hold circuit for conversion. When switching channels, it is recommended to
add an acquisition delay before starting the next conversion. Refer to the ADC Operation
section for more information.
Important: To reduce the chance
of measurement error, it is recommended to discharge the Sample-and-Hold capacitor when
switching between ADC channels by starting a conversion on a channel connected to
VSS and terminating the conversion after the acquisition time has
elapsed. If the ADC does not have a dedicated VSS input channel, a free input
channel can be connected to VSS and used in place of the dedicated input
channel.