You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
194 lines
6.0 KiB
C
194 lines
6.0 KiB
C
/**********************************************************************
|
|
* $Id$ 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.
|
|
* Permission to use, copy, modify, and distribute this software and its
|
|
* documentation is hereby granted, under NXP Semiconductors'
|
|
* relevant copyright 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.
|
|
**********************************************************************/
|
|
|
|
/* 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 ------------------------------ */
|
|
|