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R01UH0823EJ0100 Rev.1.00 Page 1526 of 1823

Jul 31, 2019

RX23W Group 43. Capacitive Touch Sensing Unit (CTSU)

43.3.3.2 Interrupts

There are three types of interrupts for the CTSU:

 Write request interrupt for setting registers for each channel (CTSUWR)

 Measurement data transfer request interrupt (CTSURD)

 Measurement end interrupt (CTSUFN)

(1) Write request interrupt for setting registers for each channel (CTSUWR)

Store the setting data for each measurement channel in the RAM, and set the DTC or ICU transfer corresponding to the

CTSUWR interrupt in advance. The CTSUWR interrupt is output when Status 1 transitions to Status 2. Write the setting

data of the corresponding channel from the RAM to the CTSUSSC, CTSUSO0, and CTSUSO1 registers (

Figure 43.19).

Since write access to the CTSUSO1 register controls a transition to the next status, be sure to set this register last.

Figure 43.19 Example of DTC Transfer Operation Using CTSUWR Interrupt

The registers (CTSUSSC, CTSUSO0, and CTSUSO1 registers) to be set are allocated at sequential addresses. Set the

operation at interrupt generation as shown below:

 Transfer destination address: Address of the CTSUSSC register

 Handling at the transfer destination address: Transfer 2-byte data three times by a single interrupt. (The address of

the start byte is fixed.)

 Transfer source address: CTSUSSC register data storage address for the minimum channel in the setting data stored

in the RAM

 Handling at the transfer source address: Transfer 2-byte data three times by a single interrupt. (The address of the

first byte is continued from the previous interrupt handling.)

 Number of transfers by an interrupt: Specify the number of measurements.

Channel 2

CTSUSSC

000A 0914h

000A 0916h

CTSUSO0

Write the setting of each channel

CTSU registers

Transfer

CTSUSO1

Channel 0

Channel 1

RAM

First CTSUWR interrupt

Second CTSUWR interrupt

000A 0912h

Renesas RX Series User Manual

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