Datasheet

 2009 Microchip Technology Inc. Preliminary DS41364D-page 317
PIC16F193X/LF193X
25.0 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 Power modes
• High power range with variable voltage references
(PIC16F/LF1933/1938/1939 only)
• Multiple timer resources
• Software control
• Operation during Sleep
FIGURE 25-1: CAPACITIVE SENSING BLOCK DIAGRAM
TMR0CS
CPS0
CPS1
CPS2
CPS3
CPS4
CPS5
CPS6
CPS7
CPS8
(1)
CPS9
(1)
CPS10
(1)
CPSCH<3:0>
(2)
Capacitive
Sensing
Oscillator
CPSOSC
CPSON
CPSRNG<1:0>
TMR0
0
1
Set
TMR0IF
Overflow
T0XCS
0
1
T0CKI
CPSOUT
CPS11
(1)
CPS12
(1)
CPS13
(1)
CPS14
(1)
CPS15
(1)
CPSCLK
Note 1: Reference CPSCON1 register (Register 25-2) for channels implemented on each device.
2: CPSCH3 is not implemented on PIC16F1933/1936/1938/PIC16LF1933/1936/1938.
3: If CPSON = 0, disabling capacitive sensing, no channel is selected.
4: Variable Voltage Reference selection is implemented on PIC16F/LF1934/1936/1937 only.
F
OSC/4
Timer0 Module
CPSON
(3)
T1CS<1:0>
T1OSC/
T1CKI
TMR1H:TMR1L
EN
T1GSEL<1:0>
Timer1 Gate
Control Logic
T1G
F
OSC
FOSC/4
Timer1 Module
SYNCC1OUT
SYNCC2OUT
0
1
Int.
Ref.
FVR
(4)
DAC
(4)
Ref+
Ref-
CPSRM
(4)
0
1