/************************************************************************
 *   廣州周立功單片機(jī)發(fā)展有限公司    http://www.zlgmcu.com             	*
 ************************************************************************/
/************************************************************************
 *                                                                      *
 *  系統(tǒng)定時(shí)、軟件延時(shí)處理程序   										*
 *                                                                      *
 ************************************************************************/


#include  <AT89X51.H>

//數(shù)據(jù)類型定義
#define   uchar  unsigned char				
#define   ulong  unsigned long
#define   uint   unsigned int  

//利用T0定時(shí)器以實(shí)現(xiàn)精確的延時(shí)
#define   Crystal      11059200L     		//定義晶體頻率11.592MHZ
#define   Base_50us    256-46        		//50us溢出時(shí)間基準(zhǔn)
static uint      data         Tcounter;     //基準(zhǔn)時(shí)間計(jì)數(shù)器
static bit       T0IR;                     	//T0中斷標(biāo)志

void  Delay_50us(uint _time);       		//延時(shí)函數(shù)，非中斷方式，延時(shí)時(shí)間基準(zhǔn)50us
void  TimeOut_Start(uint _time50us);		//開(kāi)始時(shí)間溢出，中斷方式,時(shí)間基準(zhǔn)50us
void  TimeOut_Stop(void);           		//停止時(shí)間溢出定時(shí)

/*-------------------------------------------------------------------------------------------
定時(shí)器0中斷函數(shù) 、用以實(shí)現(xiàn)定時(shí)功能            
 -------------------------------------------------------------------------------------------*/    
void  T0_Val(void)  interrupt   1   using  2
{
  Tcounter--;
  if(Tcounter == 0)
  {
    T0IR  = 1;              		 //時(shí)間定時(shí)到，置位標(biāo)志
    TR0   = 0;
  }
    
} 


/*-------------------------------------------------------------------------------------------
 函數(shù)原型:  void  Delay_50us(uint _time50us)		                    
 參數(shù)說(shuō)明:  _time50us延時(shí)時(shí)間基準(zhǔn)單位為50us 的個(gè)數(shù)                                                        
 返回值:    無(wú) 
 說(shuō)明:		用于系統(tǒng)時(shí)間定時(shí)                  
 -------------------------------------------------------------------------------------------*/    
void  Delay_50us(uint _time50us)
{ uint  TempCount;
  TempCount  = _time50us;
  TMOD |= 0x02;          			//T0,初值自動(dòng)重裝
  TH0  =  Base_50us;     			//設(shè)置定時(shí)初值
  TL0  =  Base_50us;
  ET0  =  0;            			//禁止T0中斷
  TR0  =  1;            			//計(jì)時(shí)開(kāi)始
  while( TempCount--)
  {
    while(!TF0);TF0  =  0;			//等待
  } 
  TR0  =  0;         
} 

/*-------------------------------------------------------------------------------------------
 函數(shù)原型:  void  TimeOut_Start(uint _time)		                    
 參數(shù)說(shuō)明:  _time 定時(shí)時(shí)間基準(zhǔn)單位為50us 的個(gè)數(shù)                                                        
 返回值:    無(wú) 
 說(shuō)明:		用于系統(tǒng)時(shí)間延時(shí)                  
 -------------------------------------------------------------------------------------------*/ 
void  TimeOut_Start(uint _time)
{
 Tcounter = _time;
 TMOD |= 0x02;          			//T0,初值自動(dòng)重裝
 TH0  =  Base_50us;     			//設(shè)置定時(shí)初值
 TL0  =  Base_50us;
 T0IR =  0;             			//清除中斷T0標(biāo)志 
 ET0  =  1;             			//使能T0中斷
 EA	  =  1;
 TR0  =  1;             			//計(jì)時(shí)開(kāi)始
}
/*

void  TimeOut_Stop(void)
{
 Tcounter=0;
 ET0  =   0;
 TR0  =   0;
}

*/