blob: a70702c31043cdba489d6267b0fbfc691ad958bd [file] [log] [blame]
/******************************************************************************
* Filename: systick.h
* Revised: 2017-05-23 12:08:52 +0200 (Tue, 23 May 2017)
* Revision: 49048
*
* Description: Prototypes for the SysTick driver.
*
* Copyright (c) 2015 - 2017, Texas Instruments Incorporated
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1) Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2) 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.
*
* 3) Neither the name of the ORGANIZATION 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 HOLDER 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.
*
******************************************************************************/
//*****************************************************************************
//
//! \addtogroup system_cpu_group
//! @{
//! \addtogroup systick_api
//! @{
//
//*****************************************************************************
#ifndef __SYSTICK_H__
#define __SYSTICK_H__
//*****************************************************************************
//
// If building with a C++ compiler, make all of the definitions in this header
// have a C binding.
//
//*****************************************************************************
#ifdef __cplusplus
extern "C"
{
#endif
#include <stdbool.h>
#include <stdint.h>
#include "../inc/hw_ints.h"
#include "../inc/hw_nvic.h"
#include "../inc/hw_types.h"
#include "debug.h"
#include "interrupt.h"
//*****************************************************************************
//
// API Functions and Prototypes
//
//*****************************************************************************
//*****************************************************************************
//
//! \brief Enables the SysTick counter.
//!
//! This will start the SysTick counter. If an interrupt handler has been
//! registered, it will be called when the SysTick counter rolls over.
//!
//! \note Calling this function will cause 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 \ref SysTickPeriodSet(). If
//! an immediate reload is required, the NVIC_ST_CURRENT register must be
//! written to force this. Any write to this register clears the SysTick
//! counter to 0 and will cause a reload with the supplied period on the next
//! clock.
//!
//! \return None
//
//*****************************************************************************
__STATIC_INLINE void
SysTickEnable(void)
{
// Enable SysTick.
HWREG(NVIC_ST_CTRL) |= NVIC_ST_CTRL_CLK_SRC | NVIC_ST_CTRL_ENABLE;
}
//*****************************************************************************
//
//! \brief Disables the SysTick counter.
//!
//! This will stop the SysTick counter. If an interrupt handler has been
//! registered, it will no longer be called until SysTick is restarted.
//!
//! \return None
//
//*****************************************************************************
__STATIC_INLINE void
SysTickDisable(void)
{
// Disable SysTick.
HWREG(NVIC_ST_CTRL) &= ~(NVIC_ST_CTRL_ENABLE);
}
//*****************************************************************************
//
//! \brief Registers an interrupt handler for the SysTick interrupt in the dynamic interrupt table.
//!
//! \note Only use this function if you want to use the dynamic vector table (in SRAM)!
//!
//! This function registers a function as the interrupt handler for a specific
//! interrupt and enables the corresponding interrupt in the interrupt controller.
//!
//! \param pfnHandler is a pointer to the function to be called when the
//! SysTick interrupt occurs.
//!
//! \return None
//!
//! \sa \ref IntRegister() for important information about registering interrupt
//! handlers.
//
//*****************************************************************************
__STATIC_INLINE void
SysTickIntRegister(void (*pfnHandler)(void))
{
// Register the interrupt handler, returning an error if an error occurs.
IntRegister(INT_SYSTICK, pfnHandler);
// Enable the SysTick interrupt.
HWREG(NVIC_ST_CTRL) |= NVIC_ST_CTRL_INTEN;
}
//*****************************************************************************
//
//! \brief Unregisters the interrupt handler for the SysTick interrupt in the dynamic interrupt table.
//!
//! This function will clear the handler to be called when a SysTick interrupt
//! occurs.
//!
//! \return None
//!
//! \sa \ref IntRegister() for important information about registering interrupt
//! handlers.
//
//*****************************************************************************
__STATIC_INLINE void
SysTickIntUnregister(void)
{
// Disable the SysTick interrupt.
HWREG(NVIC_ST_CTRL) &= ~(NVIC_ST_CTRL_INTEN);
// Unregister the interrupt handler.
IntUnregister(INT_SYSTICK);
}
//*****************************************************************************
//
//! \brief Enables the SysTick interrupt.
//!
//! This function will enable the SysTick interrupt, allowing it to be
//! reflected to the processor.
//!
//! \note The SysTick interrupt handler does not need to clear the SysTick
//! interrupt source as this is done automatically by NVIC when the interrupt
//! handler is called.
//!
//! \return None
//
//*****************************************************************************
__STATIC_INLINE void
SysTickIntEnable(void)
{
// Enable the SysTick interrupt.
HWREG(NVIC_ST_CTRL) |= NVIC_ST_CTRL_INTEN;
}
//*****************************************************************************
//
//! \brief Disables the SysTick interrupt.
//!
//! This function will disable the SysTick interrupt, preventing it from being
//! reflected to the processor.
//!
//! \return None
//
//*****************************************************************************
__STATIC_INLINE void
SysTickIntDisable(void)
{
// Disable the SysTick interrupt.
HWREG(NVIC_ST_CTRL) &= ~(NVIC_ST_CTRL_INTEN);
}
//*****************************************************************************
//
//! \brief Sets the period of the SysTick counter.
//!
//! This function sets the rate at which the SysTick counter wraps; this
//! equals 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 NVIC_ST_CURRENT
//! register must be written. Any write to this register clears the SysTick
//! counter to 0 and will cause a reload with the \c ui32Period supplied here
//! on the next clock after the SysTick is enabled.
//!
//! \param ui32Period is the number of clock ticks in each period of the
//! SysTick counter; must be between 1 and 16,777,216 (0x1000000), both included.
//!
//! \return None
//
//*****************************************************************************
__STATIC_INLINE 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;
}
//*****************************************************************************
//
//! \brief Gets the period of the SysTick counter.
//!
//! This function returns the rate at which the SysTick counter wraps; this
//! equals to the number of processor clocks between interrupts.
//!
//! \return Returns the period of the SysTick counter.
//
//*****************************************************************************
__STATIC_INLINE uint32_t
SysTickPeriodGet(void)
{
// Return the period of the SysTick counter.
return(HWREG(NVIC_ST_RELOAD) + 1);
}
//*****************************************************************************
//
//! \brief Gets the current value of the SysTick counter.
//!
//! This function returns the current value of the SysTick counter; this will
//! be a value between the (period - 1) and zero, both included.
//!
//! \return Returns the current value of the SysTick counter
//
//*****************************************************************************
__STATIC_INLINE uint32_t
SysTickValueGet(void)
{
// Return the current value of the SysTick counter.
return(HWREG(NVIC_ST_CURRENT));
}
//*****************************************************************************
//
// Mark the end of the C bindings section for C++ compilers.
//
//*****************************************************************************
#ifdef __cplusplus
}
#endif
#endif // __SYSTICK_H__
//*****************************************************************************
//
//! Close the Doxygen group
//! @}
//! @}
//
//*****************************************************************************