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diff --git a/driverlib/systick.c b/driverlib/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.
+//
+//*****************************************************************************
+
+//*****************************************************************************
+//
+//! \addtogroup systick_api
+//! @{
+//
+//*****************************************************************************
+
+#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"
+
+//*****************************************************************************
+//
+//! Enables the SysTick counter.
+//!
+//! This function starts the SysTick counter.  If an interrupt handler has been
+//! registered, it is called when the SysTick counter rolls over.
+//!
+//! \note Calling this function causes the SysTick counter to (re)commence
+//! counting from its current value.  The counter is not automatically reloaded
+//! with the period as specified in a previous call to SysTickPeriodSet().  If
+//! an immediate reload is required, the \b NVIC_ST_CURRENT register must be
+//! written to force the reload.  Any write to this register clears the SysTick
+//! counter to 0 and causes a reload with the supplied period on the next
+//! clock.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+SysTickEnable(void)
+{
+    //
+    // Enable SysTick.
+    //
+    HWREG(NVIC_ST_CTRL) |= NVIC_ST_CTRL_CLK_SRC | NVIC_ST_CTRL_ENABLE;
+}
+
+//*****************************************************************************
+//
+//! Disables the SysTick counter.
+//!
+//! This function stops the SysTick counter.  If an interrupt handler has been
+//! registered, it is not called until SysTick is restarted.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+SysTickDisable(void)
+{
+    //
+    // Disable SysTick.
+    //
+    HWREG(NVIC_ST_CTRL) &= ~(NVIC_ST_CTRL_ENABLE);
+}
+
+//*****************************************************************************
+//
+//! Registers an interrupt handler for the SysTick interrupt.
+//!
+//! \param pfnHandler is a pointer to the function to be called when the
+//! SysTick interrupt occurs.
+//!
+//! This function registers the handler to be called when a SysTick interrupt
+//! occurs.
+//!
+//! \sa IntRegister() for important information about registering interrupt
+//! handlers.
+//!
+//! \return None.
+//
+//*****************************************************************************
+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;
+}
+
+//*****************************************************************************
+//
+//! Unregisters the interrupt handler for the SysTick interrupt.
+//!
+//! This function unregisters the handler to be called when a SysTick interrupt
+//! occurs.
+//!
+//! \sa IntRegister() for important information about registering interrupt
+//! handlers.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+SysTickIntUnregister(void)
+{
+    //
+    // Disable the SysTick interrupt.
+    //
+    HWREG(NVIC_ST_CTRL) &= ~(NVIC_ST_CTRL_INTEN);
+
+    //
+    // Unregister the interrupt handler.
+    //
+    IntUnregister(FAULT_SYSTICK);
+}
+
+//*****************************************************************************
+//
+//! Enables the SysTick interrupt.
+//!
+//! This function enables the SysTick interrupt, allowing it to be
+//! reflected to the processor.
+//!
+//! \note The SysTick interrupt handler is not required to clear the SysTick
+//! interrupt source because it is cleared automatically by the NVIC when the
+//! interrupt handler is called.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+SysTickIntEnable(void)
+{
+    //
+    // Enable the SysTick interrupt.
+    //
+    HWREG(NVIC_ST_CTRL) |= NVIC_ST_CTRL_INTEN;
+}
+
+//*****************************************************************************
+//
+//! Disables the SysTick interrupt.
+//!
+//! This function disables the SysTick interrupt, preventing it from being
+//! reflected to the processor.
+//!
+//! \return None.
+//
+//*****************************************************************************
+void
+SysTickIntDisable(void)
+{
+    //
+    // Disable the SysTick interrupt.
+    //
+    HWREG(NVIC_ST_CTRL) &= ~(NVIC_ST_CTRL_INTEN);
+}
+
+//*****************************************************************************
+//
+//! Sets the period of the SysTick counter.
+//!
+//! \param ui32Period is the number of clock ticks in each period of the
+//! SysTick counter and must be between 1 and 16,777,216, inclusive.
+//!
+//! This function sets the rate at which the SysTick counter wraps, which
+//! equates to the number of processor clocks between interrupts.
+//!
+//! \note Calling this function does not cause the SysTick counter to reload
+//! immediately.  If an immediate reload is required, the \b NVIC_ST_CURRENT
+//! register must be written.  Any write to this register clears the SysTick
+//! counter to 0 and causes a reload with the \e ui32Period supplied here on
+//! the next clock after SysTick is enabled.
+//!
+//! \return None.
+//
+//*****************************************************************************
+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;
+}
+
+//*****************************************************************************
+//
+//! Gets the period of the SysTick counter.
+//!
+//! This function returns the rate at which the SysTick counter wraps, which
+//! equates to the number of processor clocks between interrupts.
+//!
+//! \return Returns the period of the SysTick counter.
+//
+//*****************************************************************************
+uint32_t
+SysTickPeriodGet(void)
+{
+    //
+    // Return the period of the SysTick counter.
+    //
+    return(HWREG(NVIC_ST_RELOAD) + 1);
+}
+
+//*****************************************************************************
+//
+//! Gets the current value of the SysTick counter.
+//!
+//! This function returns the current value of the SysTick counter, which is
+//! a value between the period - 1 and zero, inclusive.
+//!
+//! \return Returns the current value of the SysTick counter.
+//
+//*****************************************************************************
+uint32_t
+SysTickValueGet(void)
+{
+    //
+    // Return the current value of the SysTick counter.
+    //
+    return(HWREG(NVIC_ST_CURRENT));
+}
+
+//*****************************************************************************
+//
+// Close the Doxygen group.
+//! @}
+//
+//*****************************************************************************