bsp_piezo.c

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#include <includes.h>
#define TCR_CNT_EN		0x00000001
#define TCR_RESET		0x00000002
#define TCR_PWM_EN		0x00000008

#define PWMMR0R			1 << 1
#define PWMENA6			1 << 14
#define LER0_EN			1 << 0
#define LER6_EN			1 << 6

CPU_INT32U  Piezo_Frequency;
CPU_INT08U   Piezo_Duration;

/*********************************************************************************************************
*                                            PWW_PiezoInit()
*
* Description : Inniatialize and enable a singled edge PWM signal of 1Khz at P1.26
*
* Argument(s) : none.
*
* Return(s)   : none.
*********************************************************************************************************
*/

void  PWW_PiezoInit (void)
{
    CPU_INT32U  pclk_freq;
    CPU_INT32U  rld_cnts;
   Piezo_Duration=0;
                                                             /* VIC timer #0 Initialization                              */
   // VICIntSelect &= ~(1 << VIC_TIMER0);                       /* Configure the timer interrupt as an IRQ source           */
   // VICVectAddr4  =  (CPU_INT32U)Tmr_TickISR_Handler;         /* Set the vector address                                   */
   // VICIntEnable  =  (1 << VIC_TIMER0);                       /* Enable the timer interrupt source                        */
  PINSEL3|=0x00200000;                                       /* (1) enable P1.26 as PWM1(6) and as an output            */
  pclk_freq     =   BSP_CPU_PclkFreq(PCLK_PWM1);            /* Get the peripheral clock frequency                       */
  rld_cnts      =   pclk_freq / 1000;             /* Calculate the # of counts necessary for the OS ticker    */
  PWM1TCR = TCR_RESET;	/* Counter Reset */ 
  PWM1PR = 0x00;	/* count frequency:Fpclk */
  PWM1MR0         =  rld_cnts;                                  /*PWW 0 controls the frequency of the waveform= 1000 Hz  */
  PWM1MR6         =  rld_cnts / 2;                              /*PWW 6 controls the duty cycle: 50 %*/
 
  PWM1MCR = PWMMR0R;     // reset on MR0
 // PWM1IR =  0x07FF;        //reset all interrupt flags
 // PWM1CCR = 0x0000;       // turn off capture mode
  //PWM1PCR	= 0x00004040;   // PWM6 enabled and selected
  PWM1PCR = PWMENA6;  /*Single edge and PWM6 output enabled*/
  PWM1LER = LER0_EN | LER6_EN; /*Enable Latchs for MR0 and MR6 registers*/
  /* (4) start the PWM1 module in PWM mode                                      */
  //PWM1TCR = TCR_CNT_EN | TCR_PWM_EN ;
}
/******************************************************************************
** Function name:		PWM_Set
**
** Descriptions:		PWM cycle setup
**
** parameters:			PWM cycle
** Returned value:		
** 
******************************************************************************/
void Piezo_Set(CPU_INT32U  cycle){
  CPU_INT32U  pclk_freq;
  CPU_INT32U  rld_cnts;
  pclk_freq     =   BSP_CPU_PclkFreq(PCLK_PWM1);            /* Get the peripheral clock frequency                       */
 
    rld_cnts      =   pclk_freq / cycle;             /* Calculate the # of counts necessary for the OS ticker    */
    PWM1MR0         =  rld_cnts;                                  /*PWW 0 controls the frequency of the waveform */
    PWM1MR6         =  rld_cnts / 2;                              /*PWW 6 controls the duty cycle: 50 %*/
    /* The LER will be cleared when the Match 0 takes place, in order to
	load and execute the new value of match registers,  PWMLERs need to
	reloaded. */
    PWM1LER = LER0_EN | LER6_EN;
}
/******************************************************************************
** Function name:		PWM_Start
**
** Descriptions:		Enable PWM by setting the PCR, PTCR registers
**
** parameters:			duration (seconds)
** Returned value:		
** 
******************************************************************************/
CPU_INT08U Piezo_Start(CPU_INT08U duration){
/* All single edge, all enable */
  if (Piezo_Duration ==0){
     Piezo_Duration = duration;
     PWM1TCR = TCR_RESET;
     PWM1PCR = PWMENA6;
     PWM1TCR = TCR_CNT_EN | TCR_PWM_EN;	/* counter enable, PWM enable */
    return DEF_TRUE;
  }else{
    return DEF_FALSE; 
  }
  
}
/******************************************************************************
** Function name:		PWM_Stop
**
** Descriptions:		Stop the PWM channel
**
** parameters:			channel number
** Returned value:		None
** 
******************************************************************************/
void Piezo_Stop( void ){

  PWM1PCR = 0;
  PWM1TCR = 0x00;		/* Stop all PWMs */

} 
/******************************************************************************
** Function name:		PiezoDurationHandler
**
** Descriptions:		Piezo Setup includes a duration, this routine is 
**                              supossed to be called every second, to decrease the
**                              timer and stop the PWM signal.
**
** parameters:			
** Returned value:		None
** 
******************************************************************************/
void PiezoDurationHandler()
{
   if(Piezo_Duration >0)
     Piezo_Duration--;
   if(Piezo_Duration==0){
     Piezo_Stop();
   }
}