Renesas RX Series User Manual

R01UH0823EJ0100 Rev.1.00 Page 1516 of 1823
Jul 31, 2019
RX23W Group 43. Capacitive Touch Sensing Unit (CTSU)
43.3.2.1 Initial Setting Flowchart
Figure 43.9 shows the flowchart for CTSU initial setting.
Figure 43.9 CTSU Initial Setting Flowchart
Figure 43.10 shows the flowchart for stopping CTSU operation and setting to the standby state.
Figure 43.10 CTSU Stopping Flowchart
When restarting operation after it has been stopped, follow the initial setting flowchart shown in Figure 43.9.
Discharge external LPF capacitor
connected to TSCAP pin
Measurement operation starts
Set I/O port
Set CTSU base clock
Enable CTSU input clock
Power on CTSU
Wait for stabilization
Set CTSU power supply
Discharge the external LPF capacitor connected to the MCU by using
the TSCAP pin as the I/O port function and driving it low for the specified time.
Set the corresponding pin to TSm (
m = 2, 3, 4, 7, 8, 12, 13, 22, 23, 27, 30, 35) by
setting the pin function select register of the multi-function pin controller (MPC)
(PijPFS = 11001b), and set the pin to the peripheral function by setting the
port mode register for the I/O port (PORTi.PMR.Bj = 1).
Enable this module clock by setting the MSTPD10 bit in module stop control
register D (MSTPCRD) to 0.
Set the CTSU power supply operating mode and capacity adjustment.
When operating the CTSU while VCC is lower than 2.4 V, set the
CTSUCR1.CTSUATUNE0 bit.
Set the CTSUCR1.CTSUATUNE1 bit according to electrostatic capacitance
generated in the electrode connected to the TS pin.
Use the CTSUCR1.CTSUCLK[1:0] and CTSUSO1.CTSUSDPA[4:0] bits to set
the base clock.
Supply power to the CTSU and connect the LPF capacitor to the TSCAP pin.
Write 1 to the CTSUCR1.CTSUPON bit and 1 to the CTSUCR1.CTSUCSW bit
at the same time.
After data is written, wait until charging of the external LPF capacitor
connected to the TSCAP pin stabilizes.
Power off CTSU
Disable this module clock by setting the MSTPD10 bit in
module stop control register D (MSTPCRD) to 1.
Enable module standby
CTSU operation completed
Power off the CTSU and disconnect the TSCAP pin
from the LPF capacitor.
Write 0 to the CTSUCR1.CTSUPON bit and
0 to the CTSUCR1.CTSUCSW bit.

Renesas RX Series Specifications

General

Brand	Renesas
Model	RX Series
Category	Microcontrollers
Language	English