STMPE811_08 datasheet(48/54 Pages) STMICROELECTRONICS

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GPIO controller

STMPE811

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GPIO_FE

Falling edge

Address:

0x16

Type:

R/W

Reset:

0x00

Description:

Falling edge has been detected.

GPIO_ALT_FUNCT

Alternate function register

Address:

0x17

Type:

R/W

Reset:

0x0F

Description:

Alternate function register. "‘0’ sets the corresponding GPIO to function as GPIO, and

‘1’ sets it to Touch Key Direct Output mode.

On power-up reset, all GPIOs are set as input.

Power supply

The STMPE811 GPIO operates from a separate supply pin (VIO). This dedicated supply pin

provides a level-shifting feature to the STMPE811. The GPIO remains valid until VIO is

removed.

The host system may choose to turn off Vcc supply while keeping VIO supplied. However it is

not allowed to turn off supply to VIO, while keeping the Vcc supplied.

The touchscreen is always powered by VIO. For better resolution and noise immunity, VIO

above 2.8 V is advised.

13.0.1

Power-up reset (POR)

The STMPE811 is equipped with an internal POR circuit that holds the device in reset state,

until the VIO supply input is valid. The internal POR is tied to the VIO supply pin.

STMPE811 데이터시트(PDF) 48 Page - STMicroelectronics