C8051F388 Datasheet, PDF (55/285 Pages) –

C8051F388/9/A/B
6.5. ADC0 Analog Multiplexer
AMUX0 selects the positive and negative inputs to the ADC. The positive input (AIN+) can be connected to
individual Port pins, the on-chip temperature sensor, or the positive power supply (V_DD). The negative
input (AIN-) can be connected to individual Port pins, VREF, or GND. When GND is selected as the nega-
tive input, ADC0 operates in Single-ended Mode; at all other times, ADC0 operates in Differential Mode.
The ADC0 input channels are selected in the AMX0P and AMX0N registers as described in SFR Definition
6.9 and SFR Definition 6.10.
Important Note About ADC0 Input Configuration: Port pins selected as ADC0 inputs should be config-
ured as analog inputs, and should be skipped by the Digital Crossbar. To configure a Port pin for analog
input, set to 0 the corresponding bit in register PnMDIN. To force the Crossbar to skip a Port pin, set to 1
the corresponding bit in register PnSKIP. See Section “20. Port Input/Output” on page 147 for more Port
I/O configuration details.
Rev. 1.1
55