sx8643 Semtech Corporation, sx8643 Datasheet - Page 22

• Manufacturer Part Number: sx8643
• Description: Ultra Low Power, Capacitive Button Touch Controller 12 Sensors With Enhanced Led Drivers
• Manufacturer: Semtech Corporation

ADVANCED COMMUNICATIONS & 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 SX8643 is then ready for operation.
During the power on period the SX8643 stabilizes the internal regulators, RC clocks and the firmware initializes all
registers.
During the power up the SX8643 is not accessible and I2C communications are forbidden.
As soon as the INTB rises the SX8643 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_5, February 10
• if a Button event occurred (touch or release if enabled). I2C register CapStatLsb show the detailed status of
• if a GPI edge occurred (rising or falling if enabled). I2C register GpiStat shows the detailed status of the GPI
• when actually entering Active or Doze mode either through automatic wakeup or via host request (may be
• once compensation procedure is completed either through automatic trigger or via host request (may be
• 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).
the Buttons,
pins,
delayed by 1 scan period). I2C register CompOpmode shows the current operation mode,
delayed by 1 scan period),
Figure 19
© 2010 Semtech Corp.
Ultra Low Power, Capacitive Button Touch Controller
Power Up vs. INTB
22
(12 sensors) with Enhanced LED Drivers
DATASHEET
www.semtech.com
SX8643