79 lines
3.0 KiB
C
79 lines
3.0 KiB
C
/***************************************************************************//**
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* @file
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* @brief Microsecond delay.
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*******************************************************************************
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* # License
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* <b>Copyright 2020 Silicon Laboratories Inc. www.silabs.com</b>
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*******************************************************************************
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*
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* SPDX-License-Identifier: Zlib
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*
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* The licensor of this software is Silicon Laboratories Inc.
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*
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* This software is provided 'as-is', without any express or implied
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* warranty. In no event will the authors be held liable for any damages
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* arising from the use of this software.
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*
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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*
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software. If you use this software
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* in a product, an acknowledgment in the product documentation would be
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* appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source distribution.
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*
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******************************************************************************/
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#ifndef UDELAY_H
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#define UDELAY_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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/***************************************************************************//**
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* @addtogroup udelay Microsecond Delay
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* @brief Microsecond delay function
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* @{
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******************************************************************************/
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/**
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* @brief
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* Delay a number of microseconds
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*
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* @details
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* This function will use a busy loop to delay code execution by a certain
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* number of microseconds before returning to the caller. This function will
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* not return to the caller earlier than the time given as the input parameter.
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* This function will not use any hardware timing peripherals, it is using
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* the core clock frequency to calculate the delay.
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*
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* Note that there will always be some overhead associated with calling this
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* function in addition to the internal delay loop. This overhead is relatively
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* small when the delay is large (>= 100us).
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*
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* The accuracy of this delay loop will be affected by interrupts and context
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* switching. If accuracy is needed, a hardware timer should be used
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* to handle delays.
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*
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* @param[in] us
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* This is the number of microseconds to delay execution. This function will
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* return after this amount of time has elapsed. Minimum value is 0 us and
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* maximum value is 100 000 us (100 ms). It is however recommended to use
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* the sleeptimer api for delays of more than 1 ms as it is using a hardware
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* counter and will result in better accuracy.
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*/
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void sl_udelay_wait(unsigned us);
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#ifdef __cplusplus
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}
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#endif
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/** @} (end addtogroup udelay) */
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#endif
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