STMPE1601 datasheet(29/61 Pages) STMICROELECTRONICS

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STMPE1601

Interrupt system

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9.2

Programming sequence

To configure and initialize the Interrupt Controller to allow interruption to host, observe the

following steps:

●

Set the INT_EN_MASK and INT_EN_GPIO_MASK registers to the desired values to

enable the interrupt sources that are to be expected to receive from.

●

Configure the output interrupt type and polarity and enable the global interrupt mask by

writing to the INT_CTRL.

●

Wait for interrupt.

●

Upon receiving an interrupt, the INT pin is asserted.

●

The host comes to read the INT_STA register through the I2C interface. A ‘1’ in the

INT_STA bits indicates that the corresponding interrupt source is triggered.

●

If the IS8 bit in INT_STA register is set, the interrupt is coming from the GPIO controller.

Then, a subsequent read is performed on the INT_STA_GPIO register to obtain the

interrupt status of all 16 GPIOs to locate the GPIO that triggers the interrupt. This is a

feature so-called ‘Hot Key’.

●

After obtaining the interrupt source that triggers the interrupt, the host performs the

necessary processing and operations related to the interrupt source.

●

If the interrupt source is from the GPIO Controller, two write operations with value of ‘1’

are performed to the ISG[x] bit (INT_STA_GPIO) and the IS[8] (ISR) to clear the

corresponding GPIO interrupt.

●

If the interrupt source is from other module, a write operation with value of ‘1’ is

performed to the IS[x] (ISR) to clear the corresponding interrupt.

●

Once the interrupt is being cleared, the INT pin will also be de-asserted if the interrupt

type is level interrupt. An edge interrupt will only assert a pulse width of 250ns.

●

When the interrupt is no longer required, the IC0 bit in INT_CTRL may be set to ‘0’ to

disable the global interrupt mask bit.

STMPE1601 Datasheet(PDF) 29 Page - STMicroelectronics