PIC16F722AT-ISS Datasheet, PDF (117/286 Pages) Microchip Technology – 28-Pin Flash Microcontrollers with nanoWatt XLP Technology

PIC16(L)F722A/723A
14.0 CAPACITIVE SENSING
MODULE
The capacitive sensing module allows for an interaction
with an end user without a mechanical interface. In a
typical application, the capacitive sensing module is
attached to a pad on a printed circuit board (PCB), which
is electrically isolated from the end user. When the end
user places their finger over the PCB pad, a capacitive
load is added, causing a frequency shift in the capacitive
sensing module. The capacitive sensing module
requires software and at least one timer resource to
determine the change in frequency. Key features of this
module include:
• Analog MUX for monitoring multiple inputs
• Capacitive sensing oscillator
• Multiple timer resources
• Software control
• Operation during Sleep
FIGURE 14-1:
CAPACITIVE SENSING BLOCK DIAGRAM
T0XCS
T0CKI
0
1
FOSC/4
Timer0 Module
T0CS
Set
T0IF
0
TMR0
Overflow
1
CPS0
CPS1
CPS2
CPS3
CPS4
CPS5
CPS6
CPS7
CPSCH<2:0>
CPSON⁽¹⁾
CPSON
Capacitive
Sensing
Oscillator
CPSOSC
CPSCLK
CPSOUT
CPSRNG<1:0>
T1CS<1:0>
FOSC
FOSC/4
T1OSC/
T1CKI
T1GSEL<1:0>
T1G
Timer1 Module
TMR1H:TMR1L
EN
Timer1 Gate
Control Logic
Watchdog Timer Module
LP WDT
OSC
WDT ^Overflow
Scaler
PS<2:0>
WDT
Event
TMR2
Timer2 Module
Overflow
Postscaler
Set
TMR2IF
Note 1: If CPSON = 0, disabling capacitive sensing, no channel is selected.
 2010-2012 Microchip Technology Inc.
DS41417B-page 117