Diff: libs/LPC17xx/LPC17xxLib/src/lpc17xx_systick.c

Revision:

2:1df0b61d3b5a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libs/LPC17xx/LPC17xxLib/src/lpc17xx_systick.c	Fri Feb 28 18:52:52 2014 -0800
@@ -0,0 +1,190 @@
+#ifdef __LPC17XX__
+
+/**********************************************************************
+* $Id$		lpc17xx_systick.c				2010-05-21
+*//**
+* @file		lpc17xx_systick.c
+* @brief	Contains all functions support for SYSTICK firmware library
+* 			on LPC17xx
+* @version	2.0
+* @date		21. May. 2010
+* @author	NXP MCU SW Application Team
+*
+* Copyright(C) 2010, NXP Semiconductor
+* All rights reserved.
+*
+***********************************************************************
+* Software that is described herein is for illustrative purposes only
+* which provides customers with programming information regarding the
+* products. This software is supplied "AS IS" without any warranties.
+* NXP Semiconductors assumes no responsibility or liability for the
+* use of the software, conveys no license or title under any patent,
+* copyright, or mask work right to the product. NXP Semiconductors
+* reserves the right to make changes in the software without
+* notification. NXP Semiconductors also make no representation or
+* warranty that such application will be suitable for the specified
+* use without further testing or modification.
+**********************************************************************/
+
+/* Peripheral group ----------------------------------------------------------- */
+/** @addtogroup SYSTICK
+ * @{
+ */
+
+/* Includes ------------------------------------------------------------------- */
+#include "lpc17xx_systick.h"
+#include "lpc17xx_clkpwr.h"
+
+/* If this source file built with example, the LPC17xx FW library configuration
+ * file in each example directory ("lpc17xx_libcfg.h") must be included,
+ * otherwise the default FW library configuration file must be included instead
+ */
+#ifdef __BUILD_WITH_EXAMPLE__
+#include "lpc17xx_libcfg.h"
+#else
+#include "lpc17xx_libcfg_default.h"
+#endif /* __BUILD_WITH_EXAMPLE__ */
+
+
+#ifdef _SYSTICK
+
+/* Public Functions ----------------------------------------------------------- */
+/** @addtogroup SYSTICK_Public_Functions
+ * @{
+ */
+/*********************************************************************//**
+ * @brief 		Initial System Tick with using internal CPU clock source
+ * @param[in]	time	time interval(ms)
+ * @return 		None
+ **********************************************************************/
+void SYSTICK_InternalInit(uint32_t time)
+{
+	uint32_t cclk;
+	float maxtime;
+
+	cclk = SystemCoreClock;
+	/* With internal CPU clock frequency for LPC17xx is 'SystemCoreClock'
+	 * And limit 24 bit for RELOAD value
+	 * So the maximum time can be set:
+	 * 1/SystemCoreClock * (2^24) * 1000 (ms)
+	 */
+	//check time value is available or not
+	maxtime = (1<<24)/(SystemCoreClock / 1000) ;
+	if(time > maxtime)
+		//Error loop
+		while(1);
+	else
+	{
+		//Select CPU clock is System Tick clock source
+		SysTick->CTRL |= ST_CTRL_CLKSOURCE;
+		/* Set RELOAD value
+		 * RELOAD = (SystemCoreClock/1000) * time - 1
+		 * with time base is millisecond
+		 */
+		SysTick->LOAD = (cclk/1000)*time - 1;
+	}
+}
+
+/*********************************************************************//**
+ * @brief 		Initial System Tick with using external clock source
+ * @param[in]	freq	external clock frequency(Hz)
+ * @param[in]	time	time interval(ms)
+ * @return 		None
+ **********************************************************************/
+void SYSTICK_ExternalInit(uint32_t freq, uint32_t time)
+{
+	float maxtime;
+
+	/* With external clock frequency for LPC17xx is 'freq'
+	 * And limit 24 bit for RELOAD value
+	 * So the maximum time can be set:
+	 * 1/freq * (2^24) * 1000 (ms)
+	 */
+	//check time value is available or not
+	maxtime = (1<<24)/(freq / 1000) ;
+	if (time>maxtime)
+		//Error Loop
+		while(1);
+	else
+	{
+		//Select external clock is System Tick clock source
+		SysTick->CTRL &= ~ ST_CTRL_CLKSOURCE;
+		/* Set RELOAD value
+		 * RELOAD = (freq/1000) * time - 1
+		 * with time base is millisecond
+		 */
+		maxtime = (freq/1000)*time - 1;
+		SysTick->LOAD = (freq/1000)*time - 1;
+	}
+}
+
+/*********************************************************************//**
+ * @brief 		Enable/disable System Tick counter
+ * @param[in]	NewState	System Tick counter status, should be:
+ * 					- ENABLE
+ * 					- DISABLE
+ * @return 		None
+ **********************************************************************/
+void SYSTICK_Cmd(FunctionalState NewState)
+{
+	CHECK_PARAM(PARAM_FUNCTIONALSTATE(NewState));
+
+	if(NewState == ENABLE)
+		//Enable System Tick counter
+		SysTick->CTRL |= ST_CTRL_ENABLE;
+	else
+		//Disable System Tick counter
+		SysTick->CTRL &= ~ST_CTRL_ENABLE;
+}
+
+/*********************************************************************//**
+ * @brief 		Enable/disable System Tick interrupt
+ * @param[in]	NewState	System Tick interrupt status, should be:
+ * 					- ENABLE
+ * 					- DISABLE
+ * @return 		None
+ **********************************************************************/
+void SYSTICK_IntCmd(FunctionalState NewState)
+{
+	CHECK_PARAM(PARAM_FUNCTIONALSTATE(NewState));
+
+	if(NewState == ENABLE)
+		//Enable System Tick counter
+		SysTick->CTRL |= ST_CTRL_TICKINT;
+	else
+		//Disable System Tick counter
+		SysTick->CTRL &= ~ST_CTRL_TICKINT;
+}
+
+/*********************************************************************//**
+ * @brief 		Get current value of System Tick counter
+ * @param[in]	None
+ * @return 		current value of System Tick counter
+ **********************************************************************/
+uint32_t SYSTICK_GetCurrentValue(void)
+{
+	return (SysTick->VAL);
+}
+
+/*********************************************************************//**
+ * @brief 		Clear Counter flag
+ * @param[in]	None
+ * @return 		None
+ **********************************************************************/
+void SYSTICK_ClearCounterFlag(void)
+{
+	SysTick->CTRL &= ~ST_CTRL_COUNTFLAG;
+}
+/**
+ * @}
+ */
+
+#endif /* _SYSTICK */
+
+/**
+ * @}
+ */
+
+/* --------------------------------- End Of File ------------------------------ */
+
+#endif /* __LPC17XX__ */