pwm_example.c File Reference

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Detailed Description

PWM example driver for AVR32 UC3.

This file provides an example for the PWM on AVR32 UC3 devices.

• Compiler: IAR EWAVR32 and GNU GCC for AVR32
• Supported devices: All AVR32 devices with a PWM module can be used.
• AppNote:

Author:

Atmel Corporation: http://www.atmel.com
Support and FAQ: http://support.atmel.no/

Definition in file pwm_example.c.

#include <avr32/io.h>
#include "pwm.h"
#include "gpio.h"
#include "board.h"

Go to the source code of this file.

Defines
PWM Configuration
#define	EXAMPLE_PWM_CHANNEL_ID   0
#define	EXAMPLE_PWM_FUNCTION   AVR32_PWM_0_0_FUNCTION
#define	EXAMPLE_PWM_PIN   AVR32_PWM_0_0_PIN
Functions
int	main ()
	Main function. Execution starts here.

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Define Documentation

#define EXAMPLE_PWM_CHANNEL_ID   0

Definition at line 98 of file pwm_example.c.

Referenced by main().

#define EXAMPLE_PWM_FUNCTION   AVR32_PWM_0_0_FUNCTION

Definition at line 97 of file pwm_example.c.

Referenced by main().

#define EXAMPLE_PWM_PIN   AVR32_PWM_0_0_PIN

Definition at line 96 of file pwm_example.c.

Referenced by main().

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Function Documentation

int main

(

)

Main function. Execution starts here.

Returns:

0 on success

Definition at line 117 of file pwm_example.c.

References pwm_opt_t::diva, pwm_opt_t::divb, EXAMPLE_PWM_CHANNEL_ID, EXAMPLE_PWM_FUNCTION, EXAMPLE_PWM_PIN, pwm_opt_t::prea, pwm_opt_t::preb, pwm_channel_init(), pwm_init(), PWM_MODE_LEFT_ALIGNED, PWM_POLARITY_LOW, pwm_start_channels(), and PWM_UPDATE_DUTY.

{
  pwm_opt_t pwm_opt;                                // PWM option config.
  avr32_pwm_channel_t pwm_channel = { .ccnt = 0 };  // One channel config.
  // The channel number and instance is used in several functions.
  // It's defined as local variable for ease-of-use.
  unsigned int channel_id;

  channel_id = EXAMPLE_PWM_CHANNEL_ID;
  gpio_enable_module_pin(EXAMPLE_PWM_PIN, EXAMPLE_PWM_FUNCTION);

  // PWM controller configuration.
  pwm_opt.diva = AVR32_PWM_DIVA_CLK_OFF;
  pwm_opt.divb = AVR32_PWM_DIVB_CLK_OFF;
  pwm_opt.prea = AVR32_PWM_PREA_MCK;
  pwm_opt.preb = AVR32_PWM_PREB_MCK;

  pwm_init(&pwm_opt);

  pwm_channel.CMR.calg = PWM_MODE_LEFT_ALIGNED;       // Channel mode.
  pwm_channel.CMR.cpol = PWM_POLARITY_LOW;            // Channel polarity.
  pwm_channel.CMR.cpd = PWM_UPDATE_DUTY;              // Not used the first time.
  pwm_channel.CMR.cpre = AVR32_PWM_CPRE_MCK_DIV_256;  // Channel prescaler.
  pwm_channel.cdty = 5;   // Channel duty cycle, should be < CPRD.
  pwm_channel.cprd = 20;  // Channel period.
  pwm_channel.cupd = 0;   // Channel update is not used here.
  // With these settings, the output waveform period will be :
  // (115200/256)/20 == 22.5Hz == (MCK/prescaler)/period, with MCK == 115200Hz,
  // prescaler == 256, period == 20.

  pwm_channel_init(channel_id, &pwm_channel); // Set channel configuration to channel 0.

  pwm_start_channels(1 << channel_id);  // Start channel 0.

  while(1);
}