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/*
* @brief LPC5410x specific stopwatch implementation
*
* @note
* Copyright(C) NXP Semiconductors, 2014
* All rights reserved.
*
* @par
* Software that is described herein is for illustrative purposes only
* which provides customers with programming information regarding the
* LPC products. This software is supplied "AS IS" without any warranties of
* any kind, and NXP Semiconductors and its licensor disclaim any and
* all warranties, express or implied, including all implied warranties of
* merchantability, fitness for a particular purpose and non-infringement of
* intellectual property rights. NXP Semiconductors assumes no responsibility
* or liability for the use of the software, conveys no license or rights under any
* patent, copyright, mask work right, or any other intellectual property rights in
* or to any products. NXP Semiconductors reserves the right to make changes
* in the software without notification. NXP Semiconductors also makes no
* representation or warranty that such application will be suitable for the
* specified use without further testing or modification.
*
* @par
* Permission to use, copy, modify, and distribute this software and its
* documentation is hereby granted, under NXP Semiconductors' and its
* licensor's relevant copyrights in the software, without fee, provided that it
* is used in conjunction with NXP Semiconductors microcontrollers. This
* copyright, permission, and disclaimer notice must appear in all copies of
* this code.
*/
#include "chip.h"
#include "stopwatch.h"
/*****************************************************************************
* Private types/enumerations/variables
****************************************************************************/
/* Precompute these to optimize runtime */
static uint32_t ticksPerSecond;
static uint32_t ticksPerMs;
static uint32_t ticksPerUs;
/* Use this timer for stopwatch */
#define LPC_TIMER32_1 LPC_TIMER0
/*****************************************************************************
* Public types/enumerations/variables
****************************************************************************/
/*****************************************************************************
* Private functions
****************************************************************************/
/*****************************************************************************
* Public functions
****************************************************************************/
/* Initialize stopwatch */
void StopWatch_Init(void)
{
/* Set prescaler to divide by 8 */
const uint32_t prescaleDivisor = 8;
Chip_TIMER_Init(LPC_TIMER32_1);
Chip_TIMER_PrescaleSet(LPC_TIMER32_1, prescaleDivisor - 1);
Chip_TIMER_Enable(LPC_TIMER32_1);
/* Pre-compute tick rate. */
ticksPerSecond = Chip_Clock_GetAsyncSyscon_ClockRate() / prescaleDivisor;
ticksPerMs = ticksPerSecond / 1000;
ticksPerUs = ticksPerSecond / 1000000;
}
/* Start a stopwatch */
uint32_t StopWatch_Start(void)
{
/* Return the current timer count. */
return Chip_TIMER_ReadCount(LPC_TIMER32_1);
}
/* Returns number of ticks per second of the stopwatch timer */
uint32_t StopWatch_TicksPerSecond(void)
{
return ticksPerSecond;
}
/* Converts from stopwatch ticks to mS. */
uint32_t StopWatch_TicksToMs(uint32_t ticks)
{
return ticks / ticksPerMs;
}
/* Converts from stopwatch ticks to uS. */
uint32_t StopWatch_TicksToUs(uint32_t ticks)
{
return ticks / ticksPerUs;
}
/* Converts from mS to stopwatch ticks. */
uint32_t StopWatch_MsToTicks(uint32_t mS)
{
return mS * ticksPerMs;
}
/* Converts from uS to stopwatch ticks. */
uint32_t StopWatch_UsToTicks(uint32_t uS)
{
return uS * ticksPerUs;
}
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