From bc5146b710c8be3dfa4a8601bd3ca29408ae6397 Mon Sep 17 00:00:00 2001 From: chrysn Date: Thu, 18 Oct 2012 22:26:46 +0200 Subject: unified systick handling the only change this results in in the example binaries is in the hackrf-jellybean/systick example, where the the check in systick_set_clocksource for overflowing from the stm32 area gets used. --- lib/cm3/systick.c | 149 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 149 insertions(+) create mode 100644 lib/cm3/systick.c (limited to 'lib/cm3/systick.c') diff --git a/lib/cm3/systick.c b/lib/cm3/systick.c new file mode 100644 index 0000000..325ffff --- /dev/null +++ b/lib/cm3/systick.c @@ -0,0 +1,149 @@ +/* + * This file is part of the libopencm3 project. + * + * Copyright (C) 2010 Thomas Otto + * Copyright (C) 2012 Benjamin Vernoux + * + * 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 . + */ +/** @defgroup CM3_systick_file SysTick + +@ingroup CM3_files + +@brief libopencm3 Cortex System Tick Timer + +@version 1.0.0 + +@author @htmlonly © @endhtmlonly 2010 Thomas Otto + +@date 19 August 2012 + +This library supports the System Tick timer in ARM Cortex Microcontrollers. + +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 + */ + +/**@{*/ +#include + +/*-----------------------------------------------------------------------------*/ +/** @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; +} + +/*-----------------------------------------------------------------------------*/ +/** @brief SysTick Get Calibration Value + +@returns Current calibration value +*/ +u32 systick_get_calib(void) +{ + return (STK_CALIB&0x00FFFFFF); +} +/**@}*/ + -- cgit v1.2.3