move lpc_chip_13xx files

hw/mcu/nxp/lpc_chip_13xx/src/stopwatch_13xx.c

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+/*
+ * @brief LPC13xx specific stopwatch implementation
+ *
+ * @note
+ * Copyright(C) NXP Semiconductors, 2013
+ * 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;
+
+/*****************************************************************************
+ * Public types/enumerations/variables
+ ****************************************************************************/
+
+/*****************************************************************************
+ * Private functions
+ ****************************************************************************/
+
+/*****************************************************************************
+ * Public functions
+ ****************************************************************************/
+
+/* Initialize stopwatch */
+void StopWatch_Init(void)
+{
+	/* Use timer 1. Set prescaler to divide by 8, should give ticks at 9 MHz.
+	   That gives a useable stopwatch measurement range of about 8 minutes
+	   (if system clock is running at 72 MHz). */
+	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_GetSystemClockRate() / 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;
+}