libopencm3/include/libopencm3/cm3/systick.h

135 lines
4.1 KiB
C

/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2010 Thomas Otto <tommi@viadmin.org>
* Copyright (C) 2012 Benjamin Vernoux <titanmkd@gmail.com>
*
* 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/>.
*/
/** @defgroup CM3_systick_defines SysTick Defines
*
* @brief <b>libopencm3 Defined Constants and Types for the Cortex SysTick </b>
*
* @ingroup CM3_defines
*
* @version 1.0.0
*
* @author @htmlonly &copy; @endhtmlonly 2010 Thomas Otto <tommi@viadmin.org>
*
* @date 19 August 2012
*
* LGPL License Terms @ref lgpl_license
*/
/**
* @note this file has been not following the register naming scheme, the
* correct names defined, and the old ones stay there for compatibility with
* old software (will be deprecated in the future)
*/
/**@{*/
#ifndef LIBOPENCM3_SYSTICK_H
#define LIBOPENCM3_SYSTICK_H
#include <libopencm3/cm3/memorymap.h>
#include <libopencm3/cm3/common.h>
/* --- SYSTICK registers --------------------------------------------------- */
/* Control and status register (STK_CTRL) */
#define STK_CSR MMIO32(SYS_TICK_BASE + 0x00)
/* reload value register (STK_LOAD) */
#define STK_RVR MMIO32(SYS_TICK_BASE + 0x04)
/* current value register (STK_VAL) */
#define STK_CVR MMIO32(SYS_TICK_BASE + 0x08)
/* calibration value register (STK_CALIB) */
#define STK_CALIB MMIO32(SYS_TICK_BASE + 0x0C)
/* --- STK_CSR values ------------------------------------------------------ */
/* Bits [31:17] Reserved, must be kept cleared. */
/* COUNTFLAG: */
#define STK_CSR_COUNTFLAG (1 << 16)
/* Bits [15:3] Reserved, must be kept cleared. */
/* CLKSOURCE: Clock source selection */
#define STK_CSR_CLKSOURCE_LSB 2
#define STK_CSR_CLKSOURCE (1 << STK_CSR_CLKSOURCE_LSB)
/** @defgroup systick_clksource Clock source selection
@ingroup CM3_systick_defines
@{*/
#if defined(__ARM_ARCH_6M__)
#define STK_CSR_CLKSOURCE_EXT (0 << STK_CSR_CLKSOURCE_LSB)
#define STK_CSR_CLKSOURCE_AHB (1 << STK_CSR_CLKSOURCE_LSB)
#else
#define STK_CSR_CLKSOURCE_AHB_DIV8 (0 << STK_CSR_CLKSOURCE_LSB)
#define STK_CSR_CLKSOURCE_AHB (1 << STK_CSR_CLKSOURCE_LSB)
#endif
/**@}*/
/* TICKINT: SysTick exception request enable */
#define STK_CSR_TICKINT (1 << 1)
/* ENABLE: Counter enable */
#define STK_CSR_ENABLE (1 << 0)
/* --- STK_RVR values ------------------------------------------------------ */
/* Bits [31:24] Reserved, must be kept cleared. */
/* RELOAD[23:0]: RELOAD value */
#define STK_RVR_RELOAD 0x00FFFFFF
/* --- STK_CVR values ------------------------------------------------------ */
/* Bits [31:24] Reserved, must be kept cleared. */
/* CURRENT[23:0]: Current counter value */
#define STK_CVR_CURRENT 0x00FFFFFF
/* --- STK_CALIB values ---------------------------------------------------- */
/* NOREF: NOREF flag */
#define STK_CALIB_NOREF (1 << 31)
/* SKEW: SKEW flag */
#define STK_CALIB_SKEW (1 << 30)
/* Bits [29:24] Reserved, must be kept cleared. */
/* TENMS[23:0]: Calibration value */
#define STK_CALIB_TENMS 0x00FFFFFF
/* --- Function Prototypes ------------------------------------------------- */
BEGIN_DECLS
void systick_set_reload(uint32_t value);
bool systick_set_frequency(uint32_t freq, uint32_t ahb);
uint32_t systick_get_reload(void);
uint32_t systick_get_value(void);
void systick_set_clocksource(uint8_t clocksource);
void systick_interrupt_enable(void);
void systick_interrupt_disable(void);
void systick_counter_enable(void);
void systick_counter_disable(void);
uint8_t systick_get_countflag(void);
void systick_clear(void);
uint32_t systick_get_calib(void);
END_DECLS
#endif
/**@}*/