/* ---------------------------------------------------------------------------- | |
* SAM Software Package License | |
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* Copyright (c) 2011, Atmel Corporation | |
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* - Redistributions of source code must retain the above copyright notice, | |
* this list of conditions and the disclaimer below. | |
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*/ | |
/** \addtogroup pwm_module Working with PWM | |
* The PWM driver provides the interface to configure and use the PWM | |
* peripheral. | |
* | |
* The PWM macrocell controls square output waveforms of 4 channels. | |
* Characteristics of output waveforms such as period, duty-cycle can be configured.\n | |
* | |
* Before enabling the channels, they must have been configured first. | |
* The main settings include: | |
* <ul> | |
* <li>Configuration of the clock generator.</li> | |
* <li>Selection of the clock for each channel.</li> | |
* <li>Configuration of output waveform characteristics, such as period, duty-cycle etc.</li> | |
* </ul> | |
* | |
* After the channels is enabled, the user must use respective update registers | |
* to change the wave characteristics to prevent unexpected output waveform. | |
* i.e. PWM_CUPDx register should be used if user want to change duty-cycle | |
* when the channel is enabled. | |
* | |
* For more accurate information, please look at the PWM section of the | |
* Datasheet. | |
* | |
* Related files :\n | |
* \ref pwmc.c\n | |
* \ref pwmc.h.\n | |
*/ | |
/*@{*/ | |
/*@}*/ | |
/** | |
* \file | |
* | |
* Implementation of the Pulse Width Modulation Controller (PWM) peripheral. | |
* | |
*/ | |
/*---------------------------------------------------------------------------- | |
* Headers | |
*----------------------------------------------------------------------------*/ | |
#include "chip.h" | |
#include <stdint.h> | |
#include <assert.h> | |
/*---------------------------------------------------------------------------- | |
* Exported functions | |
*----------------------------------------------------------------------------*/ | |
/** | |
* \brief Configures PWM clocks | |
*/ | |
void PWMC_ConfigureClocks(Pwm* pPwm, uint32_t mode) | |
{ | |
pPwm->PWM_CLK= mode; | |
} | |
/** | |
* \brief Enables the given PWM channel. | |
* | |
* This does NOT enable the corresponding pin;this must be done in the user code. | |
* | |
* \param channel Channel number. | |
*/ | |
void PWMC_EnableChannel(Pwm* pPwm,uint8_t channel) | |
{ | |
pPwm->PWM_ENA= 0x1ul<<channel; | |
} | |
/** | |
* \brief Disables the given PWM channel. | |
* | |
* Beware, channel will be effectively disabled at the end of the current period. | |
* Application can check channel is disabled using the following wait loop: | |
* while ((PWM->PWM_SR & (1 << channel)) != 0); | |
* | |
* \param channel Channel number. | |
*/ | |
void PWMC_DisableChannel(Pwm* pPwm,uint8_t channel) | |
{ | |
pPwm->PWM_DIS= 0x1ul<<channel; | |
} | |
/** | |
* \brief Enables the selected interrupts sources on a PWMC peripheral. | |
*/ | |
void PWMC_EnableChannelIt(Pwm* pPwm,uint8_t channel) | |
{ | |
pPwm->PWM_IER1= 0x1ul<<channel; | |
} | |
/** | |
* \brief Disables the selected interrupts sources on a PWMC peripheral. | |
*/ | |
void PWMC_DisableChannelIt(Pwm* pPwm,uint8_t channel) | |
{ | |
pPwm->PWM_IDR1 = 0x1ul<<channel; | |
} | |
/** | |
* \brief Configures PWM a channel with the given parameters, basic configure function. | |
* | |
* The PWM controller must have been clocked in the PMC prior to calling this | |
* function. | |
* Beware: this function disables the channel. It waits until disable is effective. | |
* | |
* \param channel Channel number. | |
* \param prescaler Channel prescaler. | |
* \param alignment Channel alignment. | |
* \param polarity Channel polarity. | |
*/ | |
void PWMC_ConfigureChannel(Pwm* pPwm,uint8_t channel,uint32_t mode) | |
{ | |
pPwm->PWM_CH_NUM[channel].PWM_CMR= mode; | |
} | |
/** | |
* \brief Sets the period value used by a PWM channel. | |
* | |
* This function writes directly to the CPRD register if the channel is disabled; | |
* otherwise, it uses the update register CPRDUPD. | |
* | |
* \param channel Channel number. | |
* \param period Period value. | |
*/ | |
void PWMC_SetPeriod( Pwm* pPwm, uint8_t channel, uint16_t period) | |
{ | |
/* If channel is disabled, write to CPRD */ | |
if ((pPwm->PWM_SR & (1 << channel)) == 0) { | |
pPwm->PWM_CH_NUM[channel].PWM_CPRD = period; | |
} | |
/* Otherwise use update register */ | |
else { | |
pPwm->PWM_CH_NUM[channel].PWM_CPRDUPD = period; | |
} | |
} | |
/** | |
* \brief Sets the duty cycle used by a PWM channel. | |
* This function writes directly to the CDTY register if the channel is disabled; | |
* otherwise it uses the update register CDTYUPD. | |
* Note that the duty cycle must always be inferior or equal to the channel | |
* period. | |
* | |
* \param channel Channel number. | |
* \param duty Duty cycle value. | |
*/ | |
void PWMC_SetDutyCycle( Pwm* pPwm, uint8_t channel, uint16_t duty) | |
{ | |
assert(duty <= pPwm->PWM_CH_NUM[channel].PWM_CPRD); | |
/* If channel is disabled, write to CDTY */ | |
if ((pPwm->PWM_SR & (1 << channel)) == 0) { | |
pPwm->PWM_CH_NUM[channel].PWM_CDTY = duty; | |
} | |
/* Otherwise use update register */ | |
else { | |
pPwm->PWM_CH_NUM[channel].PWM_CPRDUPD = duty; | |
} | |
} | |