sx8661 Semtech Corporation, sx8661 Datasheet - Page 30

• Manufacturer Part Number: sx8661
• Description: Low Power, Capacitive Button Touch And Proximity Controller 8 Sensors With Led Drivers And Analog Output
• Manufacturer: Semtech Corporation

SX8661
Low Power, Capacitive Button Touch and Proximity Controller
(8 sensors) with LED Drivers and Analog Output
ADVANCED COMMUNICATIONS & SENSING
DATASHEET
3.18 General Purpose Input and Outputs
The SX8661 offers eight General Purpose Input and Outputs (GPIO) pins which can be configured in any of these
modes:
- GPP (General Purpose PWM)
- GPO (General Purpose Output)
- SPO (Special Purpose Output)
The input state of the GPIO is only used during the initial phase of the power up period.
Each of these GPIO 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 = 1 (a), polarity = 0 (b)
Figure 28
The PWM blocks used in GPP and GPO modes are 8-bits based and clocked at 2MHz typ. hence offering 256
selectable pulse width values with a granularity of 0.5us typ.
PWM definition, (a) small pulse width, (b) large pulse width
Figure 29
3.18.1 GPP mode
GPIOs configured as GPP will operate as PWM outputs directly controlled by the host. A typical application is
LED dimming.
Typical GPP operation is illustrated in figure below.
Revision v3.2, January 2011
© 2011 Semtech Corp.
www.semtech.com
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