BU21170MUV Datasheet, PDF (20/33 Pages) Rohm – Capacitive Switch Controller IC

BU21170MUV
Initialize operation
This IC is initialized and all registers are cleared by Power-on reset, WDT time-out reset, and Software reset command.
When initialization is complete, the register INI is set to ‘1’ and I/O port INT is set to ‘H’.
After the IC is initialized, write the configuration values to registers. After setting configuration values, the next action is
sensor calibration. Set ‘1’ to the registers ACT, CFG and CAL on Address 0xFF, so calibration sequence is performed.
IC’s initialization after hardware reset
Power-on-reset
WDTR (Watchdog timer timeout reset)
Software reset command
The above actions act hardware reset to the IC. Hardware reset clear the all registers to the default value and initialize
MPU. After hardware reset, MPU runs the initial sequence of firmware on Program ROM.
Power supply
Outbreak WDT timeout
Effect software reset
No
INT
and
interrupt for completion of
initialization
(Register INTERRUPT
bit INI)
=1
Yes
Clear interrupt for
completion of initialization
(Register)
Finish initialization
Figure 15. Initialization routine after hardware reset
Figure 16. Configuration sequence including clear interrupts
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TSZ22111・15・001
20/29
TSZ02201-0L5L0F300830-1-2
14.Jul.2016 Rev.002