LPCOpen Platform for LPC18XX/43XX microcontrollers
18XX43XX
LPCOpen Platform for the NXP LPC18XX/43XX family of Microcontrollers
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stopwatch_18xx_43xx.c
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/*
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* @brief LPC18xx/43xx specific stopwatch implementation
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*
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* @note
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* Copyright(C) NXP Semiconductors, 2014
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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 timer 1. Set prescaler to divide by 8 */
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const
uint32_t prescaleDivisor = 8;
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Chip_TIMER_Init
(
LPC_TIMER0
);
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Chip_TIMER_PrescaleSet
(
LPC_TIMER0
, prescaleDivisor - 1);
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Chip_TIMER_Enable
(
LPC_TIMER0
);
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/* Pre-compute tick rate. */
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ticksPerSecond
=
Chip_Clock_GetRate
(
CLK_MX_TIMER0
) / prescaleDivisor;
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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
Chip_TIMER_ReadCount
(
LPC_TIMER0
);
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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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