Si1000/1/2/3/4/5
5.5. ADC0 Analog Multiplexer
ADC0 on Si1000/1/2/3/4/5 has an analog multiplexer, referred to as AMUX0.
AMUX0 selects the positive inputs to the single-ended ADC0. Any of the following may be selected as the
positive input: Port I/O pins, the on-chip temperature sensor, Regulated Digital Supply Voltage (Output of
VREG0), VDD_MCU Supply, or the positive input may be connected to GND. The ADC0 input channels
are selected in the ADC0MX register described in SFR Definition 5.12.
ADC0MX
P0.0
Programmable
Attenuator
AIN+
ADC0
AMUX
P2.6*
Temp
Sensor
Gain=0. 5 or1
Digital Supply
VDD_MCU
*P1.0 – P1.4 are not available as device pins.
P2.4 – P2.6 are only available on Si1000/1/2/3 devices
Figure 5.7. 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 and disable the digital driver (PnMDOUT = 0 and
Port Latch = 1). To force the Crossbar to skip a Port pin, set to 1 the corresponding bit in register PnSKIP.
See Section “21. Port Input/Output” on page 207 for more Port I/O configuration details.
90
Rev. 1.0
SILICON [ SILICON ]
