EM342-RTR datasheet(48/143 Pages) SILABS

48 / 143 page

EM342

Rev 1.0

7. GPIO (General Purpose Input/Output)

The EM342 has 16 GPIO pins, which may be individually configured as follows:



General purpose output



General purpose open-drain output



Alternate output controlled by a peripheral device



Alternate open-drain output controlled by a peripheral device



Analog



General purpose input



General purpose input with pull-up or pull-down resistor

The basic structure of a single GPIO is illustrated in GPIO Block DiagramFigure 7.1.

Figure 7.1. GPIO Block Diagram

A Schmitt trigger converts the GPIO pin voltage to a digital input value. The digital input signal is then always

routed to the GPIO_PxIN register; to the alternate inputs of associated peripheral devices; to wake detection logic

if wake detection is enabled; and, for certain pins, to interrupt generation logic. Configuring a pin in analog mode

disconnects the digital input from the pin and applies a high logic level to the input of the Schmitt trigger.

Only one device at a time can control a GPIO output. The output is controlled in normal output mode by the

GPIO_PxOUT register and in alternate output mode by a peripheral device. When in input mode or analog mode,

digital output is disabled.

GPIO_PxIN

GPIO_PxOUT

GPIO_PxSET

GPIO_PxCLR

GPIO_PxWAKE

GPIO_PxCFGH/L

Alternate output

Analog

functions

Wake detection

Alternate input

VDD_PADS

GND

VDD_PADS

GND

Output control

(push pull ,

open drain , or

disabled )

Schmitt trigger

VDD_PADS

GND

Protection

diode

Protection

diode

P-MOS

N-MOS

EM342-RTR Datasheet(PDF) 48 Page - Silicon Laboratories

EM342-RTR Datasheet(HTML) 48 Page - Silicon Laboratories

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