sx8643 Semtech Corporation, sx8643 Datasheet - Page 23

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

SX8643
Ultra Low Power, Capacitive Button Touch Controller
(12 sensors) with Enhanced LED Drivers
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
3.15.4 Example
A typical example of the assertion and clearing of the INTB and the I2C communication is shown in Figure 20.
Interrupt and I2C
Figure 20
When a button is touched the SX8643 will assert the interrupt (1). The host will read the IrqSrc information over
the I2C and this clears the interrupt (2).
If the finger releases the button the interrupt will be asserted (3). The host reading the IrqSrc information will clear
the interrupt (4).
In case the host does not react to an interrupt this results in a missing touch.
3.16 General Purpose Input and Outputs
3.16.1 Introduction and Definitions
The SX8643 offers eight General Purpose Input and Outputs (GPIO) pins which can be configured in any of these
modes:
- GPI (General Purpose Input)
- GPP (General Purpose PWM)
- GPO (General Purpose Output)
Each of these modes is described in more details in the following sections.
The polarity of the GPP and GPO pins is defined as in figure below, driving an LED as example. It has to be set
accordingly in SPM parameter GpioPolarity.
Polarity definition, (a) normal, (b) inverted
Figure 21
Revision 7_5, February 10
© 2010 Semtech Corp.
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