timer.c

来自「称植到lpc2124上的UCOS2.85版 是本人初学移植和ARM的成果 可」· C语言 代码 · 共 131 行

/*****************************************************************************/
/* timer.h:  Philips LPC214x家族微控制器定义定时器的C文件	                 */
/* 作者：焦进星                                                              */
/* 时间：2008年月1月22日                                                     */
/* ARM初学                                                                   */
/*****************************************************************************/

#include "target.h"



/******************************************************************************
** Function name:		Timer0Handler
**
** Descriptions:		Timer/Counter 0 interrupt handler
**				executes each 10ms @ 60 MHz CPU Clock
**
** parameters:			None
** Returned value:		None
** 
******************************************************************************/
void Timer0_Exception(void)
{  
    T0IR = 1;			    /* clear interrupt flag MR0 */

	OSTimeTick();

    VICVectAddr = 0;		/* Acknowledge Interrupt */
}

/******************************************************************************
** Function name:		enable_timer
**
** Descriptions:		Enable timer
**
** parameters:			timer number: 0 or 1
** Returned value:		None
** 
******************************************************************************/
void enable_timer( BYTE timer_num )
{
    if ( timer_num == 0 )
    {
	     T0TCR = 1;
    }
    else
    {
	     T1TCR = 1;
    }
    return;
}

/******************************************************************************
** Function name:		disable_timer
**
** Descriptions:		Disable timer
**
** parameters:			timer number: 0 or 1
** Returned value:		None
** 
******************************************************************************/
void disable_timer( BYTE timer_num )
{
    if ( timer_num == 0 )
    {
	     T0TCR = 0;
    }
    else
    {
	     T1TCR = 0;
    }
    return;
}

/******************************************************************************
** Function name:		reset_timer
**
** Descriptions:		Reset timer
**
** parameters:			timer number: 0 or 1
** Returned value:		None
** 
******************************************************************************/
void reset_timer( BYTE timer_num )
{
    DWORD regVal;

    if ( timer_num == 0 )
    {
	     regVal = T0TCR;
	     regVal |= 0x02;	//reset
	     T0TCR = regVal;
    }
    else
    {
	     regVal = T1TCR;
	     regVal |= 0x02;	//reset
	     T1TCR = regVal;
    }
    return;
}

/******************************************************************************
** Function name:		init_timer
**
** Descriptions:		Initialize timer, set timer interval, reset timer,
**				install timer interrupt handler
**
** parameters:			None
** Returned value:		true or false, if the interrupt handler can't be
**				installed, return false.
** 
******************************************************************************/
DWORD init_timer (void) 
{	
    extern void Timer0Handler(void);

    T0MR0 = INTERVAL_10MS;	/* 10mSec = 150.000-1 counts */
    T0MCR = 3;			    /* Interrupt and TC Reset when MR0 == TC*/
	
    if ( install_irq( 0,TIMER0_INT, (void *)Timer0Handler ) == FALSE )
    {
	     return (FALSE);
    }
    else
    {
	     return (TRUE);
    }
}