107 lines
3.7 KiB
C
107 lines
3.7 KiB
C
/*
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* @brief LPC15xx specific stopwatch implementation
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*
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* @note
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* Copyright(C) NXP Semiconductors, 2013
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* All rights reserved.
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*
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* @par
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* Software that is described herein is for illustrative purposes only
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* which provides customers with programming information regarding the
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* LPC products. This software is supplied "AS IS" without any warranties of
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* any kind, and NXP Semiconductors and its licensor disclaim any and
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* all warranties, express or implied, including all implied warranties of
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* merchantability, fitness for a particular purpose and non-infringement of
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* intellectual property rights. NXP Semiconductors assumes no responsibility
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* or liability for the use of the software, conveys no license or rights under any
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* patent, copyright, mask work right, or any other intellectual property rights in
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* or to any products. NXP Semiconductors reserves the right to make changes
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* in the software without notification. NXP Semiconductors also makes no
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* representation or warranty that such application will be suitable for the
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* specified use without further testing or modification.
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*
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* @par
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* Permission to use, copy, modify, and distribute this software and its
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* documentation is hereby granted, under NXP Semiconductors' and its
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* licensor's relevant copyrights in the software, without fee, provided that it
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* is used in conjunction with NXP Semiconductors microcontrollers. This
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* copyright, permission, and disclaimer notice must appear in all copies of
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* this code.
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*/
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#include "chip.h"
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#include "stopwatch.h"
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/*****************************************************************************
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* Private types/enumerations/variables
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****************************************************************************/
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/* Precompute these to optimize runtime */
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static uint32_t ticksPerSecond;
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static uint32_t ticksPerMs;
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static uint32_t ticksPerUs;
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/*****************************************************************************
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* Public types/enumerations/variables
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****************************************************************************/
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/*****************************************************************************
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* Private functions
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****************************************************************************/
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/*****************************************************************************
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* Public functions
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****************************************************************************/
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/* Initialize stopwatch */
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void StopWatch_Init(void)
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{
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/* Use Repetitive Interrupt Timer (RIT) */
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Chip_RIT_Init(LPC_RITIMER);
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Chip_RIT_SetCompareValue(LPC_RITIMER, (uint32_t) 0xFFFFFFFF);
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Chip_RIT_EnableCompClear(LPC_RITIMER);
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Chip_RIT_Enable(LPC_RITIMER);
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/* Pre-compute tick rate. */
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ticksPerSecond = Chip_Clock_GetSystemClockRate();
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ticksPerMs = ticksPerSecond / 1000;
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ticksPerUs = ticksPerSecond / 1000000;
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}
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/* Start a stopwatch */
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uint32_t StopWatch_Start(void)
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{
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/* Return the current timer count. */
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return (uint32_t) Chip_RIT_GetCounter(LPC_RITIMER);
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}
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/* Returns number of ticks per second of the stopwatch timer */
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uint32_t StopWatch_TicksPerSecond(void)
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{
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return ticksPerSecond;
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}
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/* Converts from stopwatch ticks to mS. */
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uint32_t StopWatch_TicksToMs(uint32_t ticks)
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{
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return ticks / ticksPerMs;
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}
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/* Converts from stopwatch ticks to uS. */
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uint32_t StopWatch_TicksToUs(uint32_t ticks)
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{
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return ticks / ticksPerUs;
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}
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/* Converts from mS to stopwatch ticks. */
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uint32_t StopWatch_MsToTicks(uint32_t mS)
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{
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return mS * ticksPerMs;
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}
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/* Converts from uS to stopwatch ticks. */
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uint32_t StopWatch_UsToTicks(uint32_t uS)
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{
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return uS * ticksPerUs;
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}
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