mirror of
https://github.com/arduino/Arduino.git
synced 2024-12-02 13:24:12 +01:00
237 lines
6.4 KiB
C
237 lines
6.4 KiB
C
/* ----------------------------------------------------------------------------
|
|
* SAM Software Package License
|
|
* ----------------------------------------------------------------------------
|
|
* Copyright (c) 2011-2012, Atmel Corporation
|
|
*
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following condition is met:
|
|
*
|
|
* - Redistributions of source code must retain the above copyright notice,
|
|
* this list of conditions and the disclaimer below.
|
|
*
|
|
* Atmel's name may not be used to endorse or promote products derived from
|
|
* this software without specific prior written permission.
|
|
*
|
|
* DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
|
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
|
|
* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
|
|
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
|
|
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
|
|
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
* ----------------------------------------------------------------------------
|
|
*/
|
|
|
|
/**
|
|
* \file
|
|
*
|
|
* Implementation of Timer Counter (TC).
|
|
*
|
|
*/
|
|
|
|
/*------------------------------------------------------------------------------
|
|
* Headers
|
|
*------------------------------------------------------------------------------*/
|
|
|
|
#include "chip.h"
|
|
|
|
#include <assert.h>
|
|
|
|
/*------------------------------------------------------------------------------
|
|
* Global functions
|
|
*------------------------------------------------------------------------------*/
|
|
|
|
/**
|
|
* \brief Configures a Timer Counter Channel
|
|
*
|
|
* Configures a Timer Counter to operate in the given mode. Timer is stopped
|
|
* after configuration and must be restarted with TC_Start(). All the
|
|
* interrupts of the timer are also disabled.
|
|
*
|
|
* \param pTc Pointer to a Tc instance.
|
|
* \param channel Channel number.
|
|
* \param mode Operating mode (TC_CMR value).
|
|
*/
|
|
extern void TC_Configure( Tc *pTc, uint32_t dwChannel, uint32_t dwMode )
|
|
{
|
|
TcChannel* pTcCh ;
|
|
|
|
assert( dwChannel < (sizeof( pTc->TC_CHANNEL )/sizeof( pTc->TC_CHANNEL[0] )) ) ;
|
|
pTcCh = pTc->TC_CHANNEL+dwChannel ;
|
|
|
|
/* Disable TC clock */
|
|
pTcCh->TC_CCR = TC_CCR_CLKDIS ;
|
|
|
|
/* Disable interrupts */
|
|
pTcCh->TC_IDR = 0xFFFFFFFF ;
|
|
|
|
/* Clear status register */
|
|
pTcCh->TC_SR ;
|
|
|
|
/* Set mode */
|
|
pTcCh->TC_CMR = dwMode ;
|
|
}
|
|
|
|
/**
|
|
* \brief Reset and Start the TC Channel
|
|
*
|
|
* Enables the timer clock and performs a software reset to start the counting.
|
|
*
|
|
* \param pTc Pointer to a Tc instance.
|
|
* \param dwChannel Channel number.
|
|
*/
|
|
extern void TC_Start( Tc *pTc, uint32_t dwChannel )
|
|
{
|
|
TcChannel* pTcCh ;
|
|
|
|
assert( dwChannel < (sizeof( pTc->TC_CHANNEL )/sizeof( pTc->TC_CHANNEL[0] )) ) ;
|
|
|
|
pTcCh = pTc->TC_CHANNEL+dwChannel ;
|
|
pTcCh->TC_CCR = TC_CCR_CLKEN | TC_CCR_SWTRG ;
|
|
}
|
|
|
|
/**
|
|
* \brief Stop TC Channel
|
|
*
|
|
* Disables the timer clock, stopping the counting.
|
|
*
|
|
* \param pTc Pointer to a Tc instance.
|
|
* \param dwChannel Channel number.
|
|
*/
|
|
extern void TC_Stop(Tc *pTc, uint32_t dwChannel )
|
|
{
|
|
TcChannel* pTcCh ;
|
|
|
|
assert( dwChannel < (sizeof( pTc->TC_CHANNEL )/sizeof( pTc->TC_CHANNEL[0] )) ) ;
|
|
|
|
pTcCh = pTc->TC_CHANNEL+dwChannel ;
|
|
pTcCh->TC_CCR = TC_CCR_CLKDIS ;
|
|
}
|
|
|
|
/**
|
|
* \brief Find best MCK divisor
|
|
*
|
|
* Finds the best MCK divisor given the timer frequency and MCK. The result
|
|
* is guaranteed to satisfy the following equation:
|
|
* \code
|
|
* (MCK / (DIV * 65536)) <= freq <= (MCK / DIV)
|
|
* \endcode
|
|
* with DIV being the highest possible value.
|
|
*
|
|
* \param dwFreq Desired timer frequency.
|
|
* \param dwMCk Master clock frequency.
|
|
* \param dwDiv Divisor value.
|
|
* \param dwTcClks TCCLKS field value for divisor.
|
|
* \param dwBoardMCK Board clock frequency.
|
|
*
|
|
* \return 1 if a proper divisor has been found, otherwise 0.
|
|
*/
|
|
extern uint32_t TC_FindMckDivisor( uint32_t dwFreq, uint32_t dwMCk, uint32_t *dwDiv, uint32_t *dwTcClks, uint32_t dwBoardMCK )
|
|
{
|
|
const uint32_t adwDivisors[5] = { 2, 8, 32, 128, dwBoardMCK / 32768 } ;
|
|
|
|
uint32_t dwIndex = 0 ;
|
|
|
|
/* Satisfy lower bound */
|
|
while ( dwFreq < ((dwMCk / adwDivisors[dwIndex]) / 65536) )
|
|
{
|
|
dwIndex++ ;
|
|
|
|
/* If no divisor can be found, return 0 */
|
|
if ( dwIndex == (sizeof( adwDivisors )/sizeof( adwDivisors[0] )) )
|
|
{
|
|
return 0 ;
|
|
}
|
|
}
|
|
|
|
/* Try to maximize DIV while satisfying upper bound */
|
|
while ( dwIndex < 4 )
|
|
{
|
|
|
|
if ( dwFreq > (dwMCk / adwDivisors[dwIndex + 1]) )
|
|
{
|
|
break ;
|
|
}
|
|
dwIndex++ ;
|
|
}
|
|
|
|
/* Store results */
|
|
if ( dwDiv )
|
|
{
|
|
*dwDiv = adwDivisors[dwIndex] ;
|
|
}
|
|
if ( dwTcClks )
|
|
{
|
|
*dwTcClks = dwIndex ;
|
|
}
|
|
|
|
return 1 ;
|
|
}
|
|
|
|
/**
|
|
* \brief Read Timer Counter Counter Value on the selected TC & channel.
|
|
*
|
|
* \param p_tc Pointer to a TC instance.
|
|
* \param ul_channel Channel to configure.
|
|
*
|
|
* \return RC value.
|
|
*/
|
|
uint32_t TC_ReadCV(Tc *p_tc, uint32_t ul_channel){
|
|
return p_tc->TC_CHANNEL[ul_channel].TC_CV;
|
|
}
|
|
|
|
/**
|
|
* \brief Get current status on the selected channel.
|
|
*
|
|
* \param p_tc Pointer to a TC instance.
|
|
* \param ul_channel Channel to configure.
|
|
*
|
|
* \return The current TC status.
|
|
*/
|
|
uint32_t TC_GetStatus(Tc *p_tc, uint32_t ul_channel)
|
|
{
|
|
TcChannel *tc_channel;
|
|
|
|
tc_channel = p_tc->TC_CHANNEL + ul_channel;
|
|
return tc_channel->TC_SR;
|
|
}
|
|
|
|
/**
|
|
* \brief Set RA on the selected channel.
|
|
*
|
|
* \param tc Pointer to a TC instance.
|
|
* \param chan Channel to configure.
|
|
* \param v New value for RA.
|
|
*/
|
|
void TC_SetRA(Tc *tc, uint32_t chan, uint32_t v) {
|
|
tc->TC_CHANNEL[chan].TC_RA = v;
|
|
}
|
|
|
|
/**
|
|
* \brief Set RB on the selected channel.
|
|
*
|
|
* \param tc Pointer to a TC instance.
|
|
* \param chan Channel to configure.
|
|
* \param v New value for RB.
|
|
*/
|
|
void TC_SetRB(Tc *tc, uint32_t chan, uint32_t v) {
|
|
tc->TC_CHANNEL[chan].TC_RB = v;
|
|
}
|
|
|
|
/**
|
|
* \brief Set RC on the selected channel.
|
|
*
|
|
* \param tc Pointer to a TC instance.
|
|
* \param chan Channel to configure.
|
|
* \param v New value for RC.
|
|
*/
|
|
void TC_SetRC(Tc *tc, uint32_t chan, uint32_t v) {
|
|
tc->TC_CHANNEL[chan].TC_RC = v;
|
|
}
|
|
|