278 lines
8.7 KiB
C
278 lines
8.7 KiB
C
//*****************************************************************************
|
|
//
|
|
// systick.c - Driver for the SysTick timer in NVIC.
|
|
//
|
|
// Copyright (c) 2005-2017 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 2.1.4.178 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.
|
|
//! @}
|
|
//
|
|
//*****************************************************************************
|