/* ---------------------------------------------------------------------------- | |
* ATMEL Microcontroller Software Support | |
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* Copyright (c) 2009, Atmel Corporation | |
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*/ | |
/** \addtogroup ssc_module Working with SSC | |
* The SSC driver provides the interface to configure and use the SSC | |
* peripheral. | |
* | |
* !Usage | |
* | |
* -# Enable the SSC interface pins. | |
* -# Configure the SSC to operate at a specific frequency by calling | |
* SSC_Configure(). This function enables the peripheral clock of the SSC, | |
* but not its PIOs. | |
* -# Configure the transmitter and/or the receiver using the | |
* SSC_ConfigureTransmitter() and SSC_ConfigureEmitter() functions. | |
* -# Enable the PIOs or the transmitter and/or the received. | |
* -# Enable the transmitter and/or the receiver using SSC_EnableTransmitter() | |
* and SSC_EnableReceiver() | |
* -# Send data through the transmitter using SSC_Write() and SSC_WriteBuffer() | |
* -# Receive data from the receiver using SSC_Read() and SSC_ReadBuffer() | |
* -# Disable the transmitter and/or the receiver using SSC_DisableTransmitter() | |
* and SSC_DisableReceiver() | |
* | |
* For more accurate information, please look at the RTC section of the | |
* Datasheet. | |
* | |
* Related files :\n | |
* \ref ssc.c\n | |
* \ref ssc.h.\n | |
*/ | |
/*@{*/ | |
/*@}*/ | |
/** | |
* \file | |
* | |
* Implementation of Synchronous Serial (SSC) controller. | |
* | |
*/ | |
/*---------------------------------------------------------------------------- | |
* Headers | |
*----------------------------------------------------------------------------*/ | |
#include "chip.h" | |
/*---------------------------------------------------------------------------- | |
* Exported functions | |
*----------------------------------------------------------------------------*/ | |
/** | |
* \brief Configures a SSC peripheral.If the divided clock is not used, the master | |
* clock frequency can be set to 0. | |
* \note The emitter and transmitter are disabled by this function. | |
* \param bitRate bit rate. | |
* \param masterClock master clock. | |
*/ | |
void SSC_Configure(uint32_t bitRate, uint32_t masterClock) | |
{ | |
/* Enable SSC peripheral clock */ | |
PMC->PMC_PCER0 = 1 << ID_SSC; | |
/* Reset, disable receiver & transmitter */ | |
SSC->SSC_CR = SSC_CR_RXDIS | SSC_CR_TXDIS | SSC_CR_SWRST; | |
SSC->SSC_PTCR = SSC_PTCR_RXTDIS | SSC_PTCR_TXTDIS; | |
/* Configure clock frequency */ | |
if (bitRate != 0) { | |
SSC->SSC_CMR = masterClock / (2 * bitRate); | |
} | |
else { | |
SSC->SSC_CMR = 0; | |
} | |
} | |
/** | |
* \brief Configures the transmitter of a SSC peripheral. | |
* \param tcmr Transmit Clock Mode Register value. | |
* \param tfmr Transmit Frame Mode Register value. | |
*/ | |
void SSC_ConfigureTransmitter(uint32_t tcmr, uint32_t tfmr) | |
{ | |
SSC->SSC_TCMR = tcmr; | |
SSC->SSC_TFMR = tfmr; | |
} | |
/** | |
* \brief Configures the receiver of a SSC peripheral. | |
* \param rcmr Receive Clock Mode Register value. | |
* \param rfmr Receive Frame Mode Register value. | |
*/ | |
void SSC_ConfigureReceiver(uint32_t rcmr, uint32_t rfmr) | |
{ | |
SSC->SSC_RCMR = rcmr; | |
SSC->SSC_RFMR = rfmr; | |
} | |
/** | |
* \brief Enables the transmitter of a SSC peripheral. | |
*/ | |
void SSC_EnableTransmitter(void) | |
{ | |
SSC->SSC_CR = SSC_CR_TXEN; | |
} | |
/** | |
* \brief Disables the transmitter of a SSC peripheral. | |
*/ | |
void SSC_DisableTransmitter(void) | |
{ | |
SSC->SSC_CR = SSC_CR_TXDIS; | |
} | |
/** | |
* \brief Enables the receiver of a SSC peripheral. | |
*/ | |
void SSC_EnableReceiver(void) | |
{ | |
SSC->SSC_CR = SSC_CR_RXEN; | |
} | |
/** | |
* \brief Disables the receiver of a SSC peripheral. | |
*/ | |
void SSC_DisableReceiver(void) | |
{ | |
SSC->SSC_CR = SSC_CR_RXDIS; | |
} | |
/** | |
* \brief Enables one or more interrupt sources of a SSC peripheral. | |
* \param sources Bitwise OR of selected interrupt sources. | |
*/ | |
void SSC_EnableInterrupts(uint32_t sources) | |
{ | |
SSC->SSC_IER = sources; | |
} | |
/** | |
* \brief Disables one or more interrupt sources of a SSC peripheral. | |
* \param sources Bitwise OR of selected interrupt sources. | |
*/ | |
void SSC_DisableInterrupts(uint32_t sources) | |
{ | |
SSC->SSC_IDR = sources; | |
} | |
/** | |
* \brief Sends one data frame through a SSC peripheral. If another frame is currently | |
* being sent, this function waits for the previous transfer to complete. | |
* \param frame Data frame to send. | |
*/ | |
void SSC_Write(uint32_t frame) | |
{ | |
while ((SSC->SSC_SR & SSC_SR_TXRDY) == 0); | |
SSC->SSC_THR = frame; | |
} | |
/** | |
* \brief Waits until one frame is received on a SSC peripheral, and returns it. | |
*/ | |
uint32_t SSC_Read(void) | |
{ | |
while ((SSC->SSC_SR & SSC_SR_RXRDY) == 0); | |
return SSC->SSC_RHR; | |
} | |
/** | |
* \brief Sends the contents of a data buffer a SSC peripheral, using the PDC. | |
* \param buffer Data buffer to send. | |
* \param length Size of the data buffer. | |
* \return 1 if the buffer has been queued for transmission; otherwise returns 0. | |
*/ | |
uint8_t SSC_WriteBuffer(void *buffer, uint32_t length) | |
{ | |
/* Check if first bank is free*/ | |
if (SSC->SSC_TCR == 0) { | |
SSC->SSC_TPR = (uint32_t) buffer; | |
SSC->SSC_TCR = length; | |
SSC->SSC_PTCR = SSC_PTCR_TXTEN; | |
return 1; | |
} | |
/* Check if second bank is free*/ | |
else if (SSC->SSC_TNCR == 0) { | |
SSC->SSC_TNPR = (uint32_t) buffer; | |
SSC->SSC_TNCR = length; | |
return 1; | |
} | |
return 0; | |
} | |
/** | |
* \brief Reads data coming from a SSC peripheral receiver and stores it into the | |
* giving buffer with PDC. | |
* \param buffer ata buffer used for reception. | |
* \param length Size of the data buffer. | |
* \return 1 if the buffer has been queued for reception; otherwise returns 0. | |
*/ | |
uint8_t SSC_ReadBuffer(void *buffer, uint32_t length) | |
{ | |
/* Check if the first bank is free*/ | |
if (SSC->SSC_RCR == 0) { | |
SSC->SSC_RPR = (uint32_t) buffer; | |
SSC->SSC_RCR = length; | |
SSC->SSC_PTCR = SSC_PTCR_RXTEN; | |
return 1; | |
} | |
/* Check if second bank is free*/ | |
else if (SSC->SSC_RNCR == 0) { | |
SSC->SSC_RNPR = (uint32_t) buffer; | |
SSC->SSC_RNCR = length; | |
return 1; | |
} | |
return 0; | |
} |