GPIOINT - GPIO Interrupt#

GPIOINT General Purpose Input/Output Interrupt dispatcher.

The source files for the GPIO interrupt dispatcher library resides in the emdrv/gpiointerrupt folder, and are named gpiointerrupt.c and gpiointerrupt.h.

Introduction#

EFM32/EZR32/EFR32 has two GPIO interrupts lines, Odd and Even. If more than two interrupts are used then interrupt routine must dispatch from a callback register. This module provides small dispatcher for both GPIO interrupts enabling handling of up to 32 GPIO pin interrupts.

It is up to the user to configure and enable interrupt on given pin. This can be done using the GPIO library (emlib). This module handles the dispatch register and clearing of interrupt flags.

In order to use this dispatcher, it has to be initialized first by calling GPIOINT_Init(). Then each pin interrupt number must be configured by first registering the callback function for given interrupt number and then configure and enabling the interrupt number in the GPIO module.

The extended function GPIOINT_CallbackRegisterExt() may also be used to register a callback with context for a given pin number. The first available interrupt number will be returned.

The API#

This section contain brief descriptions of the functions in the API. You will find detailed information on parameters by clicking on the hyperlinked function names.

Your application code must include one header file: gpiointerrupt.h.

GPIOINT_Init()
This functions initializes the dispatcher register. Typically GPIOINT_Init() is called once in your startup code.

GPIOINT_CallbackRegister()
Register a callback function on a pin interrupt number.

GPIOINT_CallbackUnRegister()
Un-register a callback function on a pin interrupt number.

GPIOINT_CallbackRegisterExt()
Register a callback function with context on a pin number.

Example#

#include "gpiointerrupt.h"

#include "em_chip.h"
#include "em_cmu.h"
#include "em_gpio.h"

// An array to track if given pin callback was called
volatile uint8_t pinInt[32];

// Gpio callbacks called when pin interrupt was triggered.
void gpioCallback1(uint8_t intNo)
{
  pinInt[intNo]++;
}

void gpioCallback3(uint8_t intNo)
{
  pinInt[intNo]++;
}

void gpioCallback8(uint8_t intNo)
{
  pinInt[intNo]++;
}

int main(void)
{
  CHIP_Init();

  // Enable clock for GPIO module, initialize GPIOINT
  CMU_ClockEnable(cmuClock_GPIO, true);
  GPIOINT_Init();

  // Register callback functions and enable interrupts
  GPIOINT_CallbackRegister(1, gpioCallback1);
  GPIOINT_CallbackRegister(3, gpioCallback3);
  unsigned int intPin8 = GPIOINT_CallbackRegisterExt(8, gpioCallback8, (void *)callback8context);
  GPIO_IntEnable(1<<1 | 1<<3 | 1<<intPin8);

  while(true);
}

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