Renesas RX Series User Manual

R01UH0823EJ0100 Rev.1.00 Page 1495 of 1823
Jul 31, 2019
RX23W Group 43. Capacitive Touch Sensing Unit (CTSU)
CTSUCLK[1:0] Bits (CTSU Operating Clock Select)
These bits select the operating clock.
CTSUMD[1:0] Bits (CTSU Measurement Mode Select)
These bits set the measurement mode. For details, refer to
section 43.3.2, Measurement Modes.
43.2.3 CTSU Synchronous Noise Reduction Setting Register (CTSUSDPRS)
The CTSUSDPRS register should be set when the CTSUCR0.CTSUSTRT bit is 0.
CTSUPRRATIO[3:0] Bits (CTSU Measurement Time and Pulse Count Adjustment)
These bits are used to determine the measurement time and the number of measurement pulses. These are calculated by
the following formula. The number of base pulses is determined by setting the CTSUPRMODE[1:0] bits.
Number of measurement pulses = number of base pulses × (CTSUPRRATIO[3:0] bits + 1)
Measurement time = (number of base pulses × (CTSUPRRATIO[3:0] bits + 1) + (number of base pulses – 2) × 0.25) ×
base clock cycle
Note: For details on the base clock cycle, refer to section 43.2.15, CTSU Sensor Offset Register 1 (CTSUSO1).
CTSUPRMODE[1:0] Bits (CTSU Base Period and Pulse Count Setting)
These bits select the number of base pulses during measurement.
CTSUSOFF Bit (CTSU High-Pass Noise Reduction Function Off Setting)
This bit turns on or off the function for reducing high-pass noise. Set this bit to 1 when turning off the high-pass noise
reduction function.
Address(es): CTSU.CTSUSDPRS 000A 0902h
b7 b6 b5 b4 b3 b2 b1 b0
—
CTSUS
OFF
CTSUPRMODE[
1:0]
CTSUPRRATIO[3:0]
Value after reset:
00000000
Bit Symbol Bit Name Description R/W
b3 to b0 CTSUPRRATIO[3:0] CTSU Measurement Time and
Pulse Count Adjustment
Recommended setting value: 3 (0011b) R/W
b5, b4 CTSUPRMODE[1:0] CTSU Base Period and Pulse
Count Setting
b5 b4
0 0: 510 pulses
0 1: 126 pulses
1 0: 62 pulses (recommended setting value)
1 1: Setting prohibited
R/W
b6 CTSUSOFF CTSU High-Pass Noise
Reduction Function Off Setting
0: High-pass noise reduction function turned on
1: High-pass noise reduction function turned off
R/W
b7 — Reserved This bit is read as 0. The write value should be 0. R/W

Renesas RX Series Specifications

General

Core	RXv1, RXv2, RXv3
Flash Memory	Up to 8 MB
RAM	Up to 1 MB
Operating Voltage	1.62V to 5.5V
Operating Temperature	-40°C to +85°C or +105°C
Package	BGA, LQFP
ADC Resolution	12-bit
DAC Resolution	12-bit
Communication Interfaces	SCI, SPI, I2C, USB, Ethernet, CAN
Architecture	32-bit
Security Features	Memory Protection Unit (MPU)