STMPE1601 datasheet(33/61 Pages) STMICROELECTRONICS

33 / 61 page

STMPE1601

GPIO controller

33/61

10.3

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

(4 MHz clock is present) as well as Sleep mode (32 kHz clock is present).

10.3.1

Programming sequence for Hotkey

Configure the GPIO pin into GPIO mode by setting the corresponding bits in the

GPAFR.

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

Set the GPRER and GPFER 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 be put into Sleep mode if it is desired.

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.

10.3.2

Minimum pulse width

The minimum pulse width of the assertion of the Hotkey must be at least 62.5 us. Any pulse

width less than the stated value may not be registered.

STMPE1601 데이터시트(PDF) 33 Page - STMicroelectronics