C8051F80X_14 Datasheet, PDF (71/251 Pages) Silicon Laboratories – Mixed Signal ISP Flash MCU Family

C8051F80x-83x
13. Capacitive Sense (CS0)
The Capacitive Sense subsystem included on the C8051F800/1/3/4/6/7/9, C8051F810/2/3/5/6/8/9,
C8051F821/2/4/5/7/8, C8051F830/1/3/4 uses a capacitance-to-digital circuit to determine the capacitance
on a port pin. The module can take measurements from different port pins using the module’s analog mul-
tiplexer. The multiplexer supports up to 16 channels. See SFR Definition 13.9. “CS0MX: Capacitive Sense
Mux Channel Select” on page 81 for channel availability for specific part numbers. The module is enabled
only when the CS0EN bit (CS0CN) is set to 1. Otherwise the module is in a low-power shutdown state. The
module can be configured to take measurements on one port pin or a group of port pins, using auto-scan.
An accumulator can be configured to accumulate multiple conversions on an input channel. Interrupts can
be generated when CS0 completes a conversion or when the measured value crosses a threshold defined
in CS0THH:L.
CS0CN
CS0CF
CS0SS CS0SE
Auto-Scan
Logic
CS0MX
16-Bit
000
Start
001
Conversion
010
011
100
101
110
111
CS0BUSY (W)
Timer 0 Overflow
Timer 2 Overflow
Timer 1 Overflow
Reserved
Reserved
Initiated continuously
Initiated continuously
when auto-scan
enabled
Capacitance to
22-Bit Accumulator
...
Digital Converter
CS0DH:L
Greater Than
Compare Logic
CS0CMPF
CS0THH:L
Figure 13.1. CS0 Block Diagram
Rev. 1.0
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