systick.c

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//*****************************************************************************
//
// systick.c - Driver for the SysTick timer in NVIC.
//
// Copyright (c) 2005-2014 Texas Instruments Incorporated.  All rights reserved.
// Software License Agreement
// 
//   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 following disclaimer.
// 
//   Redistributions in binary form must reproduce the above copyright
//   notice, this list of conditions and the following disclaimer in the
//   documentation and/or other materials provided with the  
//   distribution.
// 
//   Neither the name of Texas Instruments Incorporated nor the names of
//   its contributors may be used to endorse or promote products derived
//   from this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS 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.
// 
// This is part of revision 2.1.0.12573 of the Tiva Peripheral Driver Library.
//
//*****************************************************************************

//*****************************************************************************
//
//
//*****************************************************************************

#include <stdbool.h>
#include <stdint.h>
#include "inc/hw_ints.h"
#include "inc/hw_nvic.h"
#include "inc/hw_types.h"
#include "driverlib/debug.h"
#include "driverlib/interrupt.h"
#include "driverlib/systick.h"

//*****************************************************************************
//
//
//*****************************************************************************
void
SysTickEnable(void)
{
    //
    // Enable SysTick.
    //
    HWREG(NVIC_ST_CTRL) |= NVIC_ST_CTRL_CLK_SRC | NVIC_ST_CTRL_ENABLE;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
SysTickDisable(void)
{
    //
    // Disable SysTick.
    //
    HWREG(NVIC_ST_CTRL) &= ~(NVIC_ST_CTRL_ENABLE);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
SysTickIntRegister(void (*pfnHandler)(void))
{
    //
    // Register the interrupt handler, returning an error if an error occurs.
    //
    IntRegister(FAULT_SYSTICK, pfnHandler);

    //
    // Enable the SysTick interrupt.
    //
    HWREG(NVIC_ST_CTRL) |= NVIC_ST_CTRL_INTEN;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
SysTickIntUnregister(void)
{
    //
    // Disable the SysTick interrupt.
    //
    HWREG(NVIC_ST_CTRL) &= ~(NVIC_ST_CTRL_INTEN);

    //
    // Unregister the interrupt handler.
    //
    IntUnregister(FAULT_SYSTICK);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
SysTickIntEnable(void)
{
    //
    // Enable the SysTick interrupt.
    //
    HWREG(NVIC_ST_CTRL) |= NVIC_ST_CTRL_INTEN;
}

//*****************************************************************************
//
//
//*****************************************************************************
void
SysTickIntDisable(void)
{
    //
    // Disable the SysTick interrupt.
    //
    HWREG(NVIC_ST_CTRL) &= ~(NVIC_ST_CTRL_INTEN);
}

//*****************************************************************************
//
//
//*****************************************************************************
void
SysTickPeriodSet(uint32_t ui32Period)
{
    //
    // Check the arguments.
    //
    ASSERT((ui32Period > 0) && (ui32Period <= 16777216));

    //
    // Set the period of the SysTick counter.
    //
    HWREG(NVIC_ST_RELOAD) = ui32Period - 1;
}

//*****************************************************************************
//
//
//*****************************************************************************
uint32_t
SysTickPeriodGet(void)
{
    //
    // Return the period of the SysTick counter.
    //
    return(HWREG(NVIC_ST_RELOAD) + 1);
}

//*****************************************************************************
//
//
//*****************************************************************************
uint32_t
SysTickValueGet(void)
{
    //
    // Return the current value of the SysTick counter.
    //
    return(HWREG(NVIC_ST_CURRENT));
}

//*****************************************************************************
//
// Close the Doxygen group.
//
//*****************************************************************************