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/* ----------------------------------------------------------------------------
* ATMEL Microcontroller Software Support
* ----------------------------------------------------------------------------
* Copyright (c) 2008, Atmel Corporation
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are 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.
* ----------------------------------------------------------------------------
*/
//------------------------------------------------------------------------------
// Headers
//------------------------------------------------------------------------------
#include "pit.h"
#include <board.h>
//------------------------------------------------------------------------------
// Global functions
//------------------------------------------------------------------------------
//------------------------------------------------------------------------------
/// Initialize the Periodic Interval Timer to generate a tick at the specified
/// period, given the current master clock frequency.
/// \param period Period in µsecond.
/// \param pit_frequency Master clock frequency in MHz.
//------------------------------------------------------------------------------
void PIT_Init(unsigned int period, unsigned int pit_frequency)
{
AT91C_BASE_PITC->PITC_PIMR = period? (period * pit_frequency + 8) >> 4 : 0;
AT91C_BASE_PITC->PITC_PIMR |= AT91C_PITC_PITEN;
}
//------------------------------------------------------------------------------
/// Set the Periodic Interval Value of the PIT.
/// \param piv PIV value to set.
//------------------------------------------------------------------------------
void PIT_SetPIV(unsigned int piv)
{
AT91C_BASE_PITC->PITC_PIMR = (AT91C_BASE_PITC->PITC_PIMR & AT91C_PITC_PIV)
| piv;
}
//------------------------------------------------------------------------------
/// Enables the PIT if this is not already the case.
//------------------------------------------------------------------------------
void PIT_Enable(void)
{
AT91C_BASE_PITC->PITC_PIMR |= AT91C_PITC_PITEN;
}
//----------------------------------------------------------------------------
/// Enable the PIT periodic interrupt.
//----------------------------------------------------------------------------
void PIT_EnableIT(void)
{
AT91C_BASE_PITC->PITC_PIMR |= AT91C_PITC_PITIEN;
}
//------------------------------------------------------------------------------
/// Disables the PIT periodic interrupt.
//------------------------------------------------------------------------------
void PIT_DisableIT(void)
{
AT91C_BASE_PITC->PITC_PIMR &= ~AT91C_PITC_PITIEN;
}
//------------------------------------------------------------------------------
/// Returns the value of the PIT mode register.
/// \return PIT_MR value.
//------------------------------------------------------------------------------
unsigned int PIT_GetMode(void)
{
return AT91C_BASE_PITC->PITC_PIMR;
}
//------------------------------------------------------------------------------
/// Returns the value of the PIT status register, clearing it as a side effect.
/// \return PIT_SR value.
//------------------------------------------------------------------------------
unsigned int PIT_GetStatus(void)
{
return AT91C_BASE_PITC->PITC_PISR;
}
//------------------------------------------------------------------------------
/// Returns the value of the PIT Image Register, to read PICNT and CPIV without
/// clearing the current values.
/// \return PIT_PIIR value.
//------------------------------------------------------------------------------
unsigned int PIT_GetPIIR(void)
{
return AT91C_BASE_PITC->PITC_PIIR;
}
//------------------------------------------------------------------------------
/// Returns the value of the PIT Value Register, clearing it as a side effect.
/// \return PIT_PIVR value.
//------------------------------------------------------------------------------
unsigned int PIT_GetPIVR(void)
{
return AT91C_BASE_PITC->PITC_PIVR;
}
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