SX8644I05AWLTRT Semtech, SX8644I05AWLTRT Datasheet - Page 24

• Manufacturer Part Number: SX8644I05AWLTRT
• Description: 12-ch Capacitive Touch Solution (Button & Slider)
• Manufacturer: Semtech

WIRELESS & SENSING
3.15 Interrupt
3.15.1 Power up
During power up the INTB is kept low. Once the power up sequence is terminated the INTB is released
autonomously. The SX8644 is then ready for operation.
During the power on period the SX8644 stabilizes the internal regulators, RC clocks and the firmware initializes all
registers.
During the power up the SX8644 is not accessible and I2C communications are forbidden.
As soon as the INTB rises the SX8644 will be ready for I2C communication.
3.15.2 Assertion
INTB is updated in Active or Doze mode once every scan period.
The INTB will be asserted: at the following events:
3.15.3 Clearing
INTB is updated in Active or Doze mode once every scan period.
The clearing of the INTB is done as soon as the host performs a read to the IrqSrc I2C register or reset is
completed
Revision 7_6, October 12
if a Button event occurred (touch or release if enabled). I2C registers CapStatMsb and CapStatLsb show the
detailed status of the Buttons,
if a Slider event occurred (touch, release, move high, move low or position change). I2C registers
CapStatMsb, SldPosMsb and SldPosLsb show the detailed status of the Slider,
if a GPI edge occurred (rising or falling if enabled). I2C register GpiStat shows the detailed status of the GPI
pins,
when actually entering Active or Doze mode either through automatic wakeup or via host request (may be
delayed by 1 scan period). I2C register CompOpmode shows the current operation mode,
once compensation procedure is completed either through automatic trigger or via host request (may be
delayed by 1 scan period),
once SPM write is effective (may be delayed by 1 scan period),
once NVM burn procedure is completed (may be delayed by 1 scan period),
during reset (power up, hardware RESETB, software reset).
Figure 24
Touch Controller (12 sensors) with Enhanced LED Drivers
© 2012 Semtech Corp.
Power Up vs. INTB
24
Ultra Low Power, Capacitive Button and Slider
DATASHEET
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SX8644