lpc17xx_systick.c
187 lines
| 5.8 KiB
| text/x-c
|
CLexer
jeandet@pc-de-jeandet3.lab-lpp.local
|
r16 | /********************************************************************** | ||
* $Id$ 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 ------------------------------ */ | ||||