R01UH0241EJ0010 Rev.0.10
Page 623 of 730
Aug 05, 2011
R8C/38T-A Group
25. Touch Sensor Control Unit
Under development Preliminary document
Specifications in this document are tentative and subject to change.
25.5
Notes on Touch Sensor Control Unit
25.5.1
Address to Store Detection Data
After measurement of each channel finishes, the values of data 1 and data 2 stored in the SFRs are transferred to
RAM using the DTC.
Do not set any area other than RAM to store data.
Use the DTC so that total 32 bits of registers TSCUDBR and TSCUPRC are transferred as measurement data
by a single DTC transfer request in Status 22.
During DTC transfer from the touch sensor control unit, set the transfer mode to repeat mode (set the MODE bit
in the DTCCRj register (j = 0 to 23) to 1) and disable interrupt generation (set the RPTINT bit in the DTCCRj
register (j = 0 to 23) to 0).
25.5.2
Measurement Trigger
In measurement trigger mode (when the TSCUCAP bit in the TSCUMR register is 1), an external trigger can
be acknowledged only in Status 0. If an external trigger is input during a measurement period, measurement
does not start.
In measurement trigger mode (when the TSCUCAP bit in the TSCUMR register is 1), if the TSCUSTRT bit in
the TSCUCR0 register is set to 0 (measurement stops) to forcibly stop during measurement, set the
TSCUINIT bit in the TSCUCR0 register to 1 for initialization after measurement is stopped.
Measurement restarts from Status 1. Set the DTC again before measurement restarts.
25.5.3
Charging Time
To prevent measurement data from being overwritten by the next measurement data, the touch sensor control
unit should be kept charged until DTC transfer is completed.
About 20 to 30 cycles of the CPU cycle are necessary for obtaining the DTC bus right and transfer time.
If the charging time is set equal to or shorter than the wait time for transfer to complete, the charging time will
exceed the set value.
25.5.4
Switching Set Values
To update any registers other than the registers for TSCU software operation, stop measurement (set the
TSCUSTRT bit to 0) before updating the set values. After the set values are updated, perform initialization (set
the TSCUINIT bit to 1) before starting measurement.
Registers for TSCU software operation
Bits CHSELXA0SW, CHSELXA1SW, and CHSELXBCSW in the TSCUCR1 register
Registers TSIE0 to TSIE2 during TSCU software operation
(To change the set values during TSCU operation, stop measurement and then perform initialization before
starting measurement.)