//******************************************************************************
//  MSP-FET430P140 Demo - USART1, SPI Interface to TLV5616 DAC
//
//  Description: Demonstrate USART0 in SPI mode interface to TLV5616 DAC.
//  USART0 is used to transmit data to DAC, software generated frame sync
//  pulse, DAC is updated inside CCR0 ISR operating in up-mode.
//  ACLK= MCLK= LFXT1= UCLK0= HF XTAL= 3.58MHz
//  //* SWRST** please see MSP430x1xx Users Guide for description *//
//  //* 3.58Mhz XTAL CRYSTAL REQUIRED - NOT INSTALLED ON FET *//
//
//               MSP430F149
//            -----------------
//        /|\|              XIN|-
//         | |                 | 3.58MHz   TLV5616
//         --|RST          XOUT|-       -------------
//           |             P5.0|------>|FS        OUT|--> 1kHz sine wave
//           |       SIMO0/P5.1|------>|DIN          |
//           |       UCLK0/P5.3|------>|SCLK       CS|-|
//           |                 |       |             | v
//
//
//  M. Buccini / G. Morton
//  Texas Instruments Inc.
//  May 2005
//  Built with Code Composer Essentials Version: 1.0
//******************************************************************************

#include  <msp430x14x.h>

unsigned int pointer;                       // 16-bit value to write

//------------------------------------------------------------------------------
// 12-bit Sine Lookup table with 32 steps
//------------------------------------------------------------------------------
static unsigned int Sin_tab[32] = {
        2048,
        2447,
        2831,
        3185,
        3495,
        3750,
        3939,
        4056,
        4095,
        4056,
        3939,
        3750,
        3495,
        3185,
        2831,
        2447,
        2048,
        1648,
        1264,
        910,
        600,
        345,
        156,
        39,
        0,
        39,
        156,
        345,
        600,
        910,
        1264,
        1648
};

void main(void)
{
  volatile unsigned int i;
  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  BCSCTL1 |= XTS;                           // ACLK= LFXT1 = HF XTAL
  do
  {
    IFG1 &= ~OFIFG;                         // Clear OSCFault flag
    for (i = 0xFF; i > 0; i--);             // Time for flag to set
  }
  while ((IFG1 & OFIFG));                   // OSCFault flag still set?

  BCSCTL2 |= SELM_3;                        // MCLK= LFXT1 (safe)
  P5SEL |= 0xA;                             // P5.1,3 SPI option select
  P5DIR |= 0xB;                             // P5.0,1,3 output direction
  P5OUT &= ~0x1;                            // FS reset
  ME2 |= USPIE1;                            // Enable USART1 SPI
  UCTL1 |= CHAR + SYNC + MM;                // 8-bit SPI Master **SWRST**
  UTCTL1 = CKPH + CKPL + SSEL0 + STC;       // Inv. delayed, ACLK, 3-pin
  UBR01 = 0x2;                              // ACLK/2 for baud rate
  UBR11 = 0x0;                              // ACLK/2 for baud rate
  UMCTL1 = 0x0;                             // Clear modulation
  UCTL1 &= ~SWRST;                          // Initialize USART state machine
  pointer = 0;                              // Clear pointer
  CCTL0 = CCIE;                             // CCR0 interrupt enabled
  CCR0 = 111;                               // Clock period of CCR0
  TACTL = TASSEL_1 + MC_1;                  // ACLK, Up-mode

  _BIS_SR(LPM0_bits + GIE);            	    // Enter LPM0 w/ interrupt
}

// Timer A0 interrupt service routine
__interrupt void Timer_A (void);
TIMERA0_ISR(Timer_A)
__interrupt void Timer_A (void)
{
  P5OUT |= 0x1;                       	    // FS set
  P5OUT &= ~0x1;                            // FS reset
  TXBUF1 = Sin_tab[pointer] >> 8;
  TXBUF1 = Sin_tab[pointer];
  pointer++;
  pointer &= 0x1F;
}