Renesas RX Series User Manual

R01UH0823EJ0100 Rev.1.00 Page 1519 of 1823
Jul 31, 2019
RX23W Group 43. Capacitive Touch Sensing Unit (CTSU)
Figure 43.13 Timing Chart of Self-Capacitance Single Scan Mode
(Measurement Start Condition is Software Trigger)
The following describes operation shown in the timing chart in Figure 43.13.
(1) After various settings are made, operation is started by writing 1 to the CTSUCR0.CTSUSTRT bit.
(2) After a channel to be measured is determined according to the preset conditions, a request for setting the
corresponding channel (CTSUWR) is output.
(3) Upon completion of writing the measurement channel settings (CTSUSSC, CTSUSO0, and CTSUSO1 registers),
the sensor drive pulse is output and the sensor ICO clock and the reference ICO clock operate.
(4) After the sensor stabilization wait time and the measurement time have elapsed and measurement is finished, a
measurement result read request (CTSURD) is output.
(5) A measurement end interrupt (CTSUFN) is output and measurement is finished (transition to Status 0).
Table 43.6 lists the touch pin states in self-capacitance single scan mode.
Table 43.6 Touch Pin States in Self-Capacitance Single Scan Mode
Status
Touch Pin
Measurement Channel Non-Measurement Channel
0 Low Low
1 Low Low
2 Low Low
3 Pulse Low
4 Pulse Low
5 Low Low
5
2
63 63
CTSUFN interrupt
0
CTSURD interrupt
CTSUST.CTSUSTC[2:0]
flags (Status)
0 3 4 (During current/count value conversion) 051
CTSUWR interrupt
Sensor stabilization wait time
(CTSUSST register)
Measurement time
Operating clock
CTSUCR0.CTSUSTRT bit
1
(1) (3) (5)
Sensor ICO clock
CTSUSC counter
Measurement result
CTSUMCH0 register
(2) (4)
Sensor drive pulse

Renesas RX Series Specifications

General

Brand	Renesas
Model	RX Series
Category	Microcontrollers
Language	English