C8051F970-A-GM Datasheet, PDF (142/454 Pages) Silicon Laboratories – Low Power Capacitive Sensing MCU with up to 32 kB of Flash

C8051F97x
18.14.1. Pin Configuration for CS0 Measurements Method
A port pin selected as CS0 input should be configured as follows:
1. Set to analog mode input by clearing to 0 the corresponding bit in register PnMDIN.
2. Force the Priority Crossbar Decoder to skip the pin by setting 1 to the corresponding bit in register PnSKIP.
3. Enable or disable the auto-ground for the pin by clearing 0 or setting 1 to the corresponding bit in the port latch
(Pn), respectively. Auto-grounding means that the pin will be grounded when CS0 measurement is not being
performed on the pin.
4. Set to 1 the corresponding bits in AMUX0Pn that CS0 will be taking measurements on.
5. If only a single channel is to be sensed, setup the CS0 Multiplexer to select the appropriate pin for
measurement. If automatic scanning is used, setup CS0SS and CS0SE registers. If multiple channels are to be
binded, the CS0MC
Important Notes:
 When CS0 is active, ADC0 must not be enabled even if ADC0 is not going to perform an operation.
 Similarly, when ADC0 is active, CS0 should not be enabled.
See Section “26. Port I/O (Port 0, Port 1, Port 2, Port 3, Port 4, Port 5, Port 6, Crossbar, and Port Match)” on
page 278 for more Port I/O configuration details.
142
Rev 1.0