STMPE1801 datasheet(34/60 Pages) STMICROELECTRONICS

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GPIO controller

STMPE1801

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Doc ID 17884 Rev 3

10.2

Hotkey feature

A GPIO is known as ‘Hotkey’ when it is configured to trigger an interruption to the host

whenever the GPIO input is being asserted. This feature is applicable in operational mode

as well as in Hibernate mode.

10.2.1

Programming sequence for Hotkey

Configure the GPIO pin into input direction by setting the corresponding bit in the GPIO

set pin direction registers [GPIO_SET_DIR_yyy].

Set the GPIO rising edge registers [GPIO_RE_yyy] and GPIO falling edge registers

[GPIO_FE_yyy] to the desired values to enable the rising edge or falling edge

detection.

Configure and enable the interrupt controller to allow the interruption to the host.

Now, the GPIO expander may enter Hibernate mode if there is no activity.

Upon any hot-key being asserted, the device will wake up and issue an interrupt to the

host.

Below are the conditions to be fulfilled in order to configure a Hot Key:

The pin is configured into GPIO mode and as input pin.

The global interrupt mask bit is enabled.

The corresponding GPIO interrupt mask bit is enabled.

10.2.2

Minimum pulse width

The minimum pulse width of the assertion of the Hotkey is dependent on the de-bounce

time configured. It must be greater than the de-bounce value configured. Any pulse width

less than the stated value may not be registered.

STMPE1801 데이터시트(PDF) 34 Page - STMicroelectronics