STMPE1601 STMicroelectronics, STMPE1601 Datasheet - Page 32

• Manufacturer Part Number: STMPE1601
• Description: 16-bit Enhanced Port Expander With Keypad And Pwm Controller Xpander Logic
• Manufacturer: STMicroelectronics

GPIO controller
10.2
10.2.1
10.2.2
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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).
Programming sequence for Hotkey
1.
2.
3.
4.
5.
6.
Below are the conditions to be fulfilled in order to configure a Hot Key:
1.
2.
3.
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.
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.
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.
STMPE1601