/** * \file * * \brief ARM functions for busy-wait delay loops * * Copyright (c) 2014-2015 Atmel Corporation. All rights reserved. * * \asf_license_start * * \page License * * 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. The name of Atmel may not be used to endorse or promote products derived * from this software without specific prior written permission. * * 4. This software may only be redistributed and used in connection with an * Atmel microcontroller product. * * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL 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. * * \asf_license_stop * */ /* * Support and FAQ: visit Atmel Support */ #ifndef CYCLE_COUNTER_H_INCLUDED #define CYCLE_COUNTER_H_INCLUDED #include #include #ifdef __cplusplus extern "C" { #endif /** * \name Convenience functions for busy-wait delay loops * * @{ */ /** * \brief Delay loop to delay n number of cycles * Delay program execution for at least the specified number of CPU cycles. * * \param n Number of cycles to delay */ static inline void delay_cycles( const uint32_t n) { if (n > 0) { SysTick->LOAD = n; SysTick->VAL = 0; while (!(SysTick->CTRL & SysTick_CTRL_COUNTFLAG_Msk)) { }; } } void delay_cycles_us(uint32_t n); void delay_cycles_ms(uint32_t n); /** * \brief Delay program execution for at least the specified number of microseconds. * * \param delay number of microseconds to wait */ #define cpu_delay_us(delay) delay_cycles_us(delay) /** * \brief Delay program execution for at least the specified number of milliseconds. * * \param delay number of milliseconds to wait */ #define cpu_delay_ms(delay) delay_cycles_ms(delay) /** * \brief Delay program execution for at least the specified number of seconds. * * \param delay number of seconds to wait */ #define cpu_delay_s(delay) delay_cycles_ms(1000 * delay) /** * @} */ #ifdef __cplusplus } #endif #endif /* CYCLE_COUNTER_H_INCLUDED */