C8051T630 Datasheet, PDF (61/221 Pages) Silicon Laboratories – Mixed-Signal Byte-Programmable EPROM MCU

C8051T630/1/2/3/4/5
11.1. Comparator Multiplexer
C8051T630/1/2/3/4/5 devices include an analog input multiplexer to connect Port I/O pins to the compara-
tor inputs. The Comparator0 inputs are selected in the CPT0MX register (SFR Definition 11.3). The
CMX0P3–CMX0P0 bits select the Comparator0 positive input; the CMX0N3–CMX0N0 bits select the
Comparator0 negative input. Important Note About Comparator Inputs: The Port pins selected as com-
parator inputs should be configured as analog inputs in their associated Port configuration register, and
configured to be skipped by the Crossbar (for details on Port configuration, see Section “20.6. Special
Function Registers for Accessing and Configuring Port I/O” on page 121).
P0.0
P0.2
P0.4
P0.6
P1.0
P1.2
P1.4
P1.6
P0.1
P0.3
P0.5
P0.7
P1.1
P1.3
P1.5
P1.7
VDD
CP0 +
+
CP0 -
-
GND
CPT0MX
Figure 11.3. Comparator Input Multiplexer Block Diagram
Rev. 1.0
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