timer.c

对于DSP自引导程序的一个实例

/*****************************************************************************************
 Description:The CPU clock : 200MHz,and the timer counter clock is CPU Clock /4 = 50MHz.
 Ver 3.0 Jun 28th,2005 By Zhang ,IPRAI
*****************************************************************************************/
#include "timer.h"
#include <stdio.h>

void timer_start(int timerNum);
//unsigned int timer_count2us(unsigned int count);
void delay_us(int timerNum , unsigned int usec);
int TIMER_INTset_ms(int timerNum,int msec);

#if 0
/*-------------------------------------*/
void timer0_cnt_start();
unsigned int  timer0_read();
void timer0_delay_us(unsigned int usec);
void timer0_halt();
void timer0_set(unsigned int Ivalue);
void timer0_start();
void timer0_INTset_ms(int msec);

void timer1_cnt_start();
unsigned int  timer1_read();
void timer1_delay_us(unsigned int usec);
void timer1_halt();
void timer1_set(unsigned int Ivalue);
void timer1_start();
void timer1_INTset_ms(int msec);
/*-------------------------------------*/
#endif

/*-------------------------------------------------------------------------*/
/* timer_start() - used to start TIMER                                   */
/*-------------------------------------------------------------------------*/
void timer_start(int timerNum)
{
//  *(unsigned volatile int *)(TIMER_CTRL_ADDR(timerNum)) &= 0xff3f;   /* hold the timer    */ 
  *(unsigned volatile int *)(TIMER_CTRL_ADDR(timerNum)) = 0;
//  SET_BIT(TIMER_CTRL_ADDR(timerNum), CLKSRC);	//Internal clock source
//  RESET_BIT(TIMER_CTRL_ADDR(timerNum), C_P);	//TIMER_PULSE_MODE
//  *(unsigned volatile int *)(TIMER_CTRL_ADDR(timerNum)) |= ((1<<CLKSRC)+(TIMER_PULSE_MODE<<C_P));     /* use CPU CLK/8     */   
  *(unsigned volatile int *)(TIMER_PERIOD_ADDR(timerNum))  |= 0xffffffff;/* set for 32 bit cnt*/
//  *(unsigned volatile int *)(TIMER_CTRL_ADDR(timerNum)) |= (1<<GO) + (1<<HLD);    /* start the timer   */
 *(unsigned volatile int *)(TIMER_CTRL_ADDR(timerNum)) = (1<<GO) + (1<<HLD) + (0<<C_P) + (1<<CLKSRC);
}

#if 0
/*-------------------------------------------------------------------------*/
/* timer_count2us() - Translate used timer count to used time in us        */
/*-------------------------------------------------------------------------*/
unsigned int timer_count2us(unsigned int count)                               
{
 return (((count*1000.0)/((unsigned int)Internal_CLK_F/1000.0)));
}
#endif

/*-------------------------------------------------------------------------*/
/* delay_us() - used to delay DSP by user specified time in msec         */
/*-------------------------------------------------------------------------*/
void delay_us(int timerNum , unsigned int usec)  
                                                 
{
  unsigned int time_start;
//  unsigned int timer_limit = (Internal_CLK_F/1000000)* usec;	
  unsigned int timer_limit = 50 * usec;  //1us = 50 TIMER_CLK:200M/4
  timer_start(timerNum);
  time_start = TIMER_READ(timerNum);
  while ((TIMER_READ(timerNum)-time_start) < timer_limit);
}


/************************************************************************************/
int TIMER_INTset_ms(int timerNum, int msec)
{
   volatile TIMER_REG  *timer_reg ;
   
   if(timerNum>2)
       return(1);
   else    
       timer_reg = (volatile TIMER_REG  *)(TIMER_CTRL_ADDR(timerNum));

   timer_reg->Control  = 0;      /* Hold it */

   timer_reg->Period  = (50000 * msec);  // 1ms=50 000 Timer_clk, (Internal_CLK_F/1000 * msec) 
/*-----------------------------------**
**  9   CLKSRC = 1  CPU clock / 4    **
**  8   C/P    = 1  Clock mode       **
**  7   /HLD   = 1  Allowed to count **
**  6   GO     = 1  Here we go       **
**-----------------------------------*/
//  timer_reg->Control  = (1<<GO) +(1<<HLD) + (1<<C_P) + (1<<CLKSRC); 	        //old code
/*************************************************************************/
    timer_reg->Control  = (1<<GO) + (1<<HLD) + (0<<C_P) + (1<<CLKSRC);
/*************************************************************************/    
    return (0);    
}









#if 0
/*-------------------------------------------------------------------------*/
/* C6000_Set_Up_TIMER_Tick_In_Microseconds() -  设置时钟中断频率           */
/*-------------------------------------------------------------------------*/
int C6000_Set_Up_TIMER_Tick_In_Microseconds (int timerNum,int Microseconds)   
{
   unsigned int clock_cycles ;

   volatile TIMER_REG  *timer_reg ;
   
   if(timerNum>2)
       return(1);
   else    
       timer_reg = (volatile TIMER_REG  *)(TIMER_CTRL_ADDR(timerNum));

   clock_cycles = (float)Microseconds * 1e-6 * Internal_CLK_F ; 

   timer_reg->Control  = 0;      /* Hold it */

   timer_reg->Period  = clock_cycles;
    
/*-----------------------------------**
**  9   CLKSRC = 1  CPU clock / 8    **
**  8   C/P    = 1  Clock mode       **
**  7   /HLD   = 1  Allowed to count **
**  6   GO     = 1  Here we go       **
**-----------------------------------*/
//  timer_reg->Control  = (1<<GO) +(1<<HLD) + (1<<C_P) + (1<<CLKSRC); 	        //old code
/*************************************************************************/
    timer_reg->Control  = (1<<GO) + (1<<HLD) + (0<<C_P) + (1<<CLKSRC);		//modified by shiyan 2002-09-18
/*************************************************************************/    
    return (0); 
}





/*-------------------------------------------------------------------------*/
/* timer0_cnt_start() - start TIMER0 to count                                  */
/*-------------------------------------------------------------------------*/
void timer0_cnt_start()
{
	*(unsigned volatile int *)TIMER0_CTL &= 0xff3f;    /* hold the timer    */
	*(unsigned volatile int *)TIMER0_CTL |= 0x200;     /* use CPU CLK/4     */   
	*(unsigned volatile int *)TIMER0_PRD |= 0xffffffff;/* set for 32 bit cnt*/
	*(unsigned volatile int *)TIMER0_CTL |= 0x3C0;      /* start the timer   */
}
/*-------------------------------------------------------------------------*/
/* timer0_read() - read TIMER0 count                               */
/*-------------------------------------------------------------------------*/
unsigned int timer0_read()
{	unsigned int i;
	i = *(unsigned volatile int *)TIMER0_COUNT;
	return i;
}
/*-------------------------------------------------------------------------*/
/* timer0_delay_us()          */
/*-------------------------------------------------------------------------*/
void timer0_delay_us(unsigned int usec)	//timer clk = 50 MHz
{
  unsigned int timer_limit = (usec*50);		//1us = 50clk;
  unsigned int time_start;

  timer0_cnt_start();
  time_start = timer0_read();
  while ((timer0_read()-time_start) < timer_limit);
}
/************************************************************************************/
void timer0_halt()		//Halt the timer1
{
 *(unsigned volatile int *)TIMER0_CTL = 0xa10;   //halt the timer
//   Rsvd    TSTAT   INVINP    CLKSRC   C/P   HLD  GO   Rsvd  PWID   DATIN   DATOUT  INVOUT  FUNC 
//  31 - 12    11      10        9       8     7    6    5      4      3        2       1      0
//   0 - 0     1       0         1       0     0    0     0     1      0        0       0      0 
}
/************************************************************************************/
void timer0_set(unsigned int Ivalue)	// Set the timer1's PRD register 
{ 
  *(unsigned volatile int *)TIMER0_PRD = Ivalue;  //Set the initial value of PRD 
}
/************************************************************************************/
void timer0_start()		//Start the timer1
{
  *(unsigned volatile int *)TIMER0_CTL |= 0x0c0;  // Start the timer    
//   Rsvd    TSTAT   INVINP    CLKSRC   C/P   HLD  GO   Rsvd  PWID   DATIN   DATOUT  INVOUT  FUNC 
//  31 - 12    11      10        9       8     7    6    5      4      3        2       1      0
//   0 - 0     1       0         1       0     1    1     0     1      0        0       0      0  
}
/************************************************************************************/
void timer0_INTset_ms(int msec)
{
  timer0_halt();
  timer0_set(50000*msec);  //1us=50 clk ,1ms=50000 clk
  timer0_start();
}

	

/*-------------------------------------------------------------------------*/
/* timer1_cnt_start() - start TIMER1 to count                              */
/*-------------------------------------------------------------------------*/
void timer1_cnt_start()
{
	*(unsigned volatile int *)TIMER1_CTL &= 0xff3f;    /* hold the timer    */
	*(unsigned volatile int *)TIMER1_CTL |= 0x200;     /* use CPU CLK/4     */   
	*(unsigned volatile int *)TIMER1_PRD |= 0xffffffff;/* set for 32 bit cnt*/
	*(unsigned volatile int *)TIMER1_CTL |= 0x3C0;      /* start the timer   */
}
/*-------------------------------------------------------------------------*/
/* timer1_read() - read TIMER1 count                               */
/*-------------------------------------------------------------------------*/
unsigned int timer1_read()
{	unsigned int i;
	i = *(unsigned volatile int *)TIMER1_COUNT;
	return i;
}
/*-------------------------------------------------------------------------*/
/* timer1_delay_us()          */
/*-------------------------------------------------------------------------*/
void timer1_delay_us(unsigned int usec)	//timer clk = 50 MHz
{
  unsigned int timer_limit = (usec*50);		//1us = 50clk;
  unsigned int time_start;

  timer1_cnt_start();
  time_start = timer1_read();
  while ((timer1_read()-time_start) < timer_limit);
}
/************************************************************************************/
void timer1_halt()		//Halt the timer1
{
 *(unsigned volatile int *)TIMER1_CTL = 0xa10;   //halt the timer
//   Rsvd    TSTAT   INVINP    CLKSRC   C/P   HLD  GO   Rsvd  PWID   DATIN   DATOUT  INVOUT  FUNC 
//  31 - 12    11      10        9       8     7    6    5      4      3        2       1      0
//   0 - 0     1       0         1       0     0    0     0     1      0        0       0      0 
}

/************************************************************************************/
void timer1_set(int Ivalue)	// Set the timer1's PRD register 
{ 
  *(unsigned volatile int *)TIMER1_PRD = Ivalue;  //Set the initial value of PRD 
}

/************************************************************************************/
void timer1_start()		//Start the timer1
{
  *(unsigned volatile int *)TIMER1_CTL |= 0x0c0;  // Start the timer    
//   Rsvd    TSTAT   INVINP    CLKSRC   C/P   HLD  GO   Rsvd  PWID   DATIN   DATOUT  INVOUT  FUNC 
//  31 - 12    11      10        9       8     7    6    5      4      3        2       1      0
//   0 - 0     1       0         1       0     1    1     0     1      0        0       0      0  
}
/************************************************************************************/
void timer1_INTset_ms(int msec)
{
  timer1_halt();
  timer1_set(50000*msec);  //1us=50 clk ,1ms=50000 clk
  timer1_start();
}
/*------------------------------------------------------------------*/
#endif