GPIO Input Interrupt

Table of Contents

• Introduction
• Supported Combinations
• Steps to Run the Example
• See Also
• Sample Output

Introduction

This example configures a GPIO pin in input mode and configures it to generate interrupt on rising edge. The application waits for 5 key presses, prints the number of times the keys are pressed and exits.

SK-AM62 or SK-AM62-LP-SK-EVM does not contain any push button connected to MCU GPIOs. This example is using MCU_GPIO0_15 pin in the MCU_HEADER(J9) for generating GPIO interrupt. Key presses can be done by connecting followed by disconnecting MCU_GPIO0_15(Pin 10 of J9) to ground (Pin 27 of J9) in the SK-AM62 or SK-AM62-LP. Please note that number of key presses will be higher than actual as we are manualy connecting the ground using jumpers.

Attention

MCU GPIO interrupt is used by Linux running on A53.

A GPIO bank interrupt can be routed to only one core at a time. For example if a gpio interrupt is routed to Linux A53 core, the same cannot be routed to other cores (M4/R5).

Before running the GPIO Input interrupt example on a processor with Linux cores, disable any overlapping entries in the Linux devicetree board file. The GPIO can be excluded from the linux device tree by modifying the device tree board file (arch/arm64/boot/dts/ti/k3-am625-sk.dts)

&mcu_gpio0 {
        status = "reserved";
};
&mcu_gpio_intr {
        status = "reserved";
};

A new linux devicetree blob (dtb) should be generated with this change and placed in the Linux filesystem in the boot folder. For more information, reference the AM62x Linux SDK docs, section Foundational Components > Kernel > Users Guide. The kernel and kernel modules do not need to be rebuilt and reinstalled.

A new linux image to be generated with this change and SoC initialization to done following SOC Initialization Using SPL . Without this change in the linux image, this example will not work.

Supported Combinations

Parameter	Value
CPU + OS	m4fss0-0 nortos
Toolchain	ti-arm-clang
Board	am62x-sk, am62x-sip-sk
Example folder	examples/drivers/gpio/gpio_input_interrupt/

Steps to Run the Example

• When using CCS projects to build, import the CCS project for the required combination and build it using the CCS project menu (see Using SDK with CCS Projects).
• When using makefiles to build, note the required combination and build using make command (see Using SDK with Makefiles)
• Launch a CCS debug session and run the executable, see CCS Launch, Load and Run

See Also

GPIO

Sample Output

Shown below is a sample output when the application is run,

GPIO Input Interrupt Test Started ...
GPIO Interrupt Configured for Rising Edge ...
Connect the MCU_GPIO0_15 pin on EVM to ground and release to trigger GPIO interrupt ...
Key is pressed 0 times
Key is pressed 0 times
Key is pressed 0 times
Key is pressed 0 times
Key is pressed 0 times
Key is pressed 0 times
Key is pressed 0 times
Key is pressed 0 times
Key is pressed 0 times
Key is pressed 0 times
Key is pressed 1 times
Key is pressed 2 times
Key is pressed 5 times
GPIO Input Interrupt Test Passed!!
All tests have passed!!