C8051T630 Datasheet, PDF (43/221 Pages) Silicon Laboratories – Mixed-Signal Byte-Programmable EPROM MCU

C8051T630/1/2/3/4/5
6.5. ADC0 Analog Multiplexer (C8051T630/2/4 only)
ADC0 on the C8051T630/2/4 uses an analog input multiplexer to select the positive input to the ADC. Any
of the following may be selected as the positive input: Port 0 and 1 I/O pins, the on-chip temperature sen-
sor, or the positive power supply (V_DD). The ADC0 input channel is selected in the AMX0P register
described in SFR Definition 6.9.
AMX0P
P0.0
AMUX
ADC0
Temp
Sensor
P1.7
VDD
Figure 6.6. ADC0 Multiplexer Block Diagram
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 109 for more Port
I/O configuration details.
Rev. 1.0
43