//*******************************************************************************
//  Provides Functions to Initialize the UCS/FLL and clock sources
//    File: hal_ucs.c
//
//    Texas Instruments
//
//    Version 1.2
//    11/24/09
//
//    V1.0  Initial Version
//    V1.1  Added timeout function
//    V1.1  Added parameter for XTDrive
//*******************************************************************************

#include "msp430.h"
#include "hal_UCS.h"

//************************************************************************
// Check and define required Defines
//************************************************************************

#ifndef XT1LFOFFG               // Defines if not available in header file
#define XT1LFOFFG 0
#endif
#ifndef XT1HFOFFG               // Defines if not available in header file
#define XT1HFOFFG 0
#endif
#ifndef XT2OFFG                 // Defines if not available in header file
#define XT2OFFG 0
#endif
#ifndef XTS                    // Defines if not available in header file
#define XTS 0
#endif
#ifndef XT2DRIVE_3             // Defines if not available in header file
#define XT2DRIVE_3  0
#endif

//====================================================================
/**
 * Startup routine for 32kHz Cristal on LFXT1
 *
*/
void LFXT_Start(uint16_t xtdrive)
{
  UCSCTL6_L |= XT1DRIVE1_L+XT1DRIVE0_L; // Highest drive setting for XT1 startup

  while (SFRIFG1 & OFIFG) {   // check OFIFG fault flag
    UCSCTL7 &= ~(DCOFFG+XT1LFOFFG+XT1HFOFFG+XT2OFFG); // Clear OSC flaut Flags fault flags
    SFRIFG1 &= ~OFIFG;        // Clear OFIFG fault flag
  }
  UCSCTL6 = (UCSCTL6 & ~(XT1DRIVE_3)) |(xtdrive); // set Drive mode
}

//====================================================================
/**
 * Startup routine for 32kHz Cristal on LFXT1 with timeout counter
 *
*/
uint16_t LFXT_Start_Timeout(uint16_t xtdrive, uint16_t timeout)
{
  UCSCTL6_L |= XT1DRIVE1_L+XT1DRIVE0_L; // Highest drive setting for XT1 startup

  while ((SFRIFG1 & OFIFG) && timeout--){   // check OFIFG fault flag
    UCSCTL7 &= ~(DCOFFG+XT1LFOFFG+XT1HFOFFG+XT2OFFG); // Clear OSC flaut Flags fault flags
    SFRIFG1 &= ~OFIFG;        // Clear OFIFG fault flag
  }
  UCSCTL6 = (UCSCTL6 & ~(XT1DRIVE_3)) |(xtdrive); // set Drive mode
  if (timeout)
    return (UCS_STATUS_OK);
  else
    return (UCS_STATUS_ERROR);
}


//====================================================================
/**
 * Startup routine for  XT1
 *
*/
void XT1_Start(uint16_t xtdrive)
{
  UCSCTL6 &= ~(XT1OFF | XT1DRIVE_3);  // enable XT1
  UCSCTL6 |= (XTS | xtdrive);         // enable XT1 and set XT1Drive

  while (SFRIFG1 & OFIFG) {   // check OFIFG fault flag
    UCSCTL7 &= ~(DCOFFG+XT1LFOFFG+XT1HFOFFG+XT2OFFG); // Clear OSC flaut Flags
    SFRIFG1 &= ~OFIFG;        // Clear OFIFG fault flag
  }
}

//====================================================================
/**
 * Startup routine for XT1 with timeout counter
 *
*/
uint16_t XT1_Start_Timeout(uint16_t xtdrive, uint16_t timeout)
{
  UCSCTL6 &= ~(XT1OFF | XT1DRIVE_3);  // enable XT1
  UCSCTL6 |= (XTS | xtdrive);         // enable XT1 and set XT1Drive

  while ((SFRIFG1 & OFIFG) && timeout--) {   // check OFIFG fault flag
    UCSCTL7 &= ~(DCOFFG+XT1LFOFFG+XT1HFOFFG+XT2OFFG); // Clear OSC flaut Flags
    SFRIFG1 &= ~OFIFG;        // Clear OFIFG fault flag
  }
  if (timeout)
    return (UCS_STATUS_OK);
  else
    return (UCS_STATUS_ERROR);
}

//====================================================================
/**
 * Use  XT1 in Bypasss mode
 *
*/
void XT1_Bypass(void)
{
  UCSCTL6 |= XT1BYPASS;

  while (SFRIFG1 & OFIFG) {   // check OFIFG fault flag
    UCSCTL7 &= ~(DCOFFG+XT1LFOFFG+XT1HFOFFG+XT2OFFG); // Clear OSC flaut Flags
    SFRIFG1 &= ~OFIFG;        // Clear OFIFG fault flag
  }
}

//====================================================================
/**
 * Startup routine for  XT2
 *
*/
void XT2_Start(uint16_t xtdrive)
{
  UCSCTL6 &= ~(XT2OFF | XT2DRIVE_3);  // enable XT2
  UCSCTL6 |= (xtdrive);               // Set XT2Drive

  while (SFRIFG1 & OFIFG) {   // check OFIFG fault flag
    UCSCTL7 &= ~(DCOFFG+XT1LFOFFG+XT1HFOFFG+XT2OFFG); // Clear OSC flaut Flags
    SFRIFG1 &= ~OFIFG;        // Clear OFIFG fault flag
  }

}

//====================================================================
/**
 * Startup routine for XT2 with timeout counter
 *
*/
uint16_t XT2_Start_Timeout(uint16_t xtdrive, uint16_t timeout)
{
  UCSCTL6 &= ~XT2OFF;                       // Set XT2 On
  UCSCTL6 &= ~XT2DRIVE_3;                   // enable XT2
  UCSCTL6 |= (xtdrive);                     // Set XT2Drive

  while ((SFRIFG1 & OFIFG) && timeout--){   // check OFIFG fault flag
    UCSCTL7 &= ~(DCOFFG+XT1LFOFFG+XT1HFOFFG+XT2OFFG); // Clear OSC flaut Flags
    SFRIFG1 &= ~OFIFG;        // Clear OFIFG fault flag
  }
  if (timeout)
    return (UCS_STATUS_OK);
  else
    return (UCS_STATUS_ERROR);
}

//====================================================================
/**
 * Use XT2 in Bypasss mode
 *
*/
void XT2_Bypass(void)
{
#ifdef XT2BYPASS              // on devices without XT2 this function will be empty
  UCSCTL6 |= XT2BYPASS;

  while (SFRIFG1 & OFIFG) {   // check OFIFG fault flag
    UCSCTL7 &= ~(DCOFFG+XT1LFOFFG+XT1HFOFFG+XT2OFFG); // Clear OSC flaut Flags
    SFRIFG1 &= ~OFIFG;        // Clear OFIFG fault flag
  }
#endif
}

//====================================================================
/**
  * Initializes FLL of the UCS and wait till settled
  *
  * \param fsystem  required system frequency (MCLK) in kHz
  * \param ratio    ratio between MCLK and FLLREFCLK
  */
void Init_FLL_Settle(uint16_t fsystem, uint16_t ratio)
{
  volatile uint16_t x = ratio * 32;       
  // save actual state of FLL loop control
  uint16_t globalInterruptState = __get_SR_register() & SCG0;
  								
  __bic_SR_register(SCG0);      // Enable FLL loop control

  Init_FLL(fsystem, ratio);
  
  while(x--)
  {
   __delay_cycles(30); 
  }
  
  __bis_SR_register(globalInterruptState);	// restore previous state

}

//====================================================================
/**
  * Initializes FLL of the UCS
  *
  * \param fsystem  required system frequency (MCLK) in kHz
  * \param ratio    ratio between fsystem and FLLREFCLK
  */
static void Init_FLL(uint16_t fsystem, uint16_t ratio)
{
  uint16_t d, dco_div_bits;
  uint16_t mode = 0;

  d = ratio;
  dco_div_bits = FLLD__2;        // Have at least a divider of 2
  if (fsystem > 16000){
    d >>= 1 ;
    mode = 1;
  }
  else
    fsystem <<= 1;               // fsystem = fsystem * 2

  while (d > 512)
  {
    dco_div_bits = dco_div_bits + FLLD0;  // set next higher div level
    d >>= 1;
  }

  UCSCTL0 = 0x000;               // Set DCO to lowest Tap

  UCSCTL2 &= ~(0x3FF);           // Reset FN bits
  UCSCTL2 = dco_div_bits | (d - 1);

  if (fsystem <= 630)            //           fsystem < 0.63MHz
	UCSCTL1= DCORSEL_0 ;
  else if (fsystem <  1250)      // 0.63MHz < fsystem < 1.25MHz
	UCSCTL1= DCORSEL_1 ;
  else if (fsystem <  2500)      // 1.25MHz < fsystem <  2.5MHz
	UCSCTL1= DCORSEL_2 ;
  else if (fsystem <  5000)      // 2.5MHz  < fsystem <    5MHz
	UCSCTL1= DCORSEL_3 ;
  else if (fsystem <  10000)     // 5MHz    < fsystem <   10MHz
	UCSCTL1= DCORSEL_4 ;
  else if (fsystem <  20000)     // 10MHz   < fsystem <   20MHz
	UCSCTL1= DCORSEL_5 ;
  else if (fsystem <  40000)     // 20MHz   < fsystem <   40MHz
	UCSCTL1= DCORSEL_6 ;
  else
	UCSCTL1= DCORSEL_7 ;

  while (SFRIFG1 & OFIFG) {                               // check OFIFG fault flag
    UCSCTL7 &= ~(DCOFFG+XT1LFOFFG+XT1HFOFFG+XT2OFFG);     // Clear OSC flaut Flags
    SFRIFG1 &= ~OFIFG;                                    // Clear OFIFG fault flag
  }

  if (mode == 1)                           		  // fsystem > 16000
    SELECT_MCLK_SMCLK(SELM__DCOCLK + SELS__DCOCLK);       // select DCOCLK
  else
   SELECT_MCLK_SMCLK(SELM__DCOCLKDIV + SELS__DCOCLKDIV); // selcet DCODIVCLK

  
} // End of fll_init()