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/** @defgroup STM32F_systick_file SysTick

@ingroup STM32F_files

@brief <b>libopencm3 STM32Fxx System Tick Timer</b>

@version 1.0.0

@author @htmlonly &copy; @endhtmlonly 2010 Thomas Otto <tommi@viadmin.org>

@date 19 August 2012

This library supports the System Tick timer in the
STM32F series of ARM Cortex Microcontrollers by ST Microelectronics.

The System Tick timer is part of the ARM Cortex core. It is a 24 bit
down counter that can be configured with an automatical reload value.

LGPL License Terms @ref lgpl_license
 */
/*
 * This file is part of the libopencm3 project.
 *
 * Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

/**@{*/
#include <libopencm3/stm32/systick.h>

/*-----------------------------------------------------------------------------*/
/** @brief SysTick Set the Automatic Reload Value.

The counter is set to the reload value when the counter starts and after it
reaches zero.

@param[in] value u32. 24 bit reload value.
*/

void systick_set_reload(u32 value)
{
	STK_LOAD = (value & 0x00FFFFFF);
}

/*-----------------------------------------------------------------------------*/
/** @brief SysTick Read the Automatic Reload Value.

@returns 24 bit reload value as u32.
*/

u32 systick_get_value(void)
{
	return STK_VAL;
}

/*-----------------------------------------------------------------------------*/
/** @brief Set the SysTick Clock Source.

The clock source can be either the AHB clock or the same clock divided by 8.

@param[in] clocksource u8. Clock source from @ref systick_clksource.
*/

void systick_set_clocksource(u8 clocksource)
{
	if (clocksource < 2)
		STK_CTRL |= (clocksource << STK_CTRL_CLKSOURCE_LSB);
}

/*-----------------------------------------------------------------------------*/
/** @brief Enable SysTick Interrupt.

*/

void systick_interrupt_enable(void)
{
	STK_CTRL |= STK_CTRL_TICKINT;
}

/*-----------------------------------------------------------------------------*/
/** @brief Disable SysTick Interrupt.

*/

void systick_interrupt_disable(void)
{
	STK_CTRL &= ~STK_CTRL_TICKINT;
}

/*-----------------------------------------------------------------------------*/
/** @brief Enable SysTick Counter.

*/

void systick_counter_enable(void)
{
	STK_CTRL |= STK_CTRL_ENABLE;
}

/*-----------------------------------------------------------------------------*/
/** @brief Disable SysTick Counter.

*/

void systick_counter_disable(void)
{
	STK_CTRL &= ~STK_CTRL_ENABLE;
}

/*-----------------------------------------------------------------------------*/
/** @brief SysTick Read the Counter Flag.

The count flag is set when the timer count becomes zero, and is cleared when the
flag is read.

@returns Boolean if flag set.
*/

u8 systick_get_countflag(void)
{
	if (STK_CTRL & STK_CTRL_COUNTFLAG)
		return 1;
	else
		return 0;
}
/**@}*/