pio_it.h File Reference

#include "pio.h"
#include <rtems.h>

Go to the source code of this file.

Functions
void	PIO_InitializeInterrupts (uint32_t dwPriority)
void	PIO_ConfigureIt (const Pin *pPin, void(*handler)(const Pin *, void *arg), void *arg)
rtems_status_code	PIO_RemoveIt (const Pin *pPin, void(*handler)(const Pin *, void *arg), void *arg)
void	PIO_IT_InterruptHandler (void)
void	PioInterruptHandler (uint32_t id, Pio *pPio)
void	PIO_CaptureHandler (void)
	The PIO_CaptureHandler must be called by the PIO Capture Interrupt Service Routine with the corresponding PIO Capture instance.

Detailed Description

Purpose

Configuration and handling of interrupts on PIO status changes. The API provided here have several advantages over the traditional PIO interrupt configuration approach:

• It is highly portable
• It automatically demultiplexes interrupts when multiples pins have been configured on a single PIO controller
• It allows a group of pins to share the same interrupt

However, it also has several minor drawbacks that may prevent from using it in particular applications:

• It enables the clocks of all PIO controllers
• PIO controllers all share the same interrupt handler, which does the demultiplexing and can be slower than direct configuration
• It reserves space for a fixed number of interrupts, which can be increased by modifying the appropriate constant in pio_it.c.

Usage

1. Initialize the PIO interrupt mechanism using PIO_InitializeInterrupts() with the desired priority (0 ... 7).
2. Configure a status change interrupt on one or more pin(s) with PIO_ConfigureIt().
3. Enable & disable interrupts on pins using PIO_EnableIt() and PIO_DisableIt().

Function Documentation

PIO_ConfigureIt()

void PIO_ConfigureIt	(	const Pin *	pPin,
		void(*)(const Pin *, void *arg)	handler,
		void *	arg
	)

Configures a PIO or a group of PIO to generate an interrupt on status change. The provided interrupt handler will be called with the triggering pin as its parameter (enabling different pin instances to share the same handler).

Parameters

pPin	Pointer to a Pin instance.
handler	Interrupt handler function pointer.
arg	Pointer to interrupt handler argument

PIO_RemoveIt()

rtems_status_code PIO_RemoveIt	(	const Pin *	pPin,
		void(*)(const Pin *, void *arg)	handler,
		void *	arg
	)

Search for a PIO interrupt and remove it if it is there.

Parameters

pPin	Pointer to a Pin instance.
handler	Interrupt handler function pointer.
arg	Pointer to interrupt handler argument

Returns

RTEMS_SUCCESSFUL if removed.

RTEMS_UNSATISFIED if the handler couldn't be found