STEVAL-TCS003V1 STMicroelectronics, STEVAL-TCS003V1 Datasheet - Page 31

• Manufacturer Part Number: STEVAL-TCS003V1
• Description: BOARD DEMO EXPANDER STMPE2403
• Manufacturer: STMicroelectronics

Specifications of STEVAL-TCS003V1

• Main Purpose: Interface, GPIO Expander
• Embedded: No
• Utilized Ic / Part: STMPE2403
• Primary Attributes: 8/16/24-Bit 24-Port GPIO Expander over I2C
• Secondary Attributes: 3 8-Bit PWM Output for LEDs, Keyboard Matrix Scan, Special Key Support
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-8206

STMPE2403
9.7
Programming sequence
To configure and initialize the Interrupt Controller to allow interruption to host, observe the
following steps:
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Set the IER and IEGPIOR 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 ICR.
Wait for interrupt.
Upon receiving an interrupt, the INT pin is asserted.
The host comes to read the ISR through I2C interface. A ‘1’ in the ISR bits indicates
that the corresponding interrupt source is triggered.
If the IS8 bit in ISR is set, the interrupt is coming from the GPIO Controller. Then, a
subsequent read is performed on the ISGPIOR to obtain the interrupt status of all 24
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 (ISGPIOR) 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 ICR may be set to ‘0’ to disable
the global interrupt mask bit.
Interrupt system
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