//******************************************************************************
//   MSP430x26x Demo - DMA0, Repeated Blk to DAC0, Sine Output, TACCR1, DCO
//
//   Description: DMA0 is used to transfer a sine look-up table word-by-word
//   as a repeating block to DAC12_0. The effect is sine wave output. Timer_A
//   operates in upmode with TACCR1 loading DAC12_0 on rising edge and
//   DAC12_0IFG triggering next DMA1 transfer. DAC12_0 uses internal 1.5V
//   reference.
//   ACLK = 32kHz, MCLK = SMCLK = TACLK = default DCO 1.045MHz
//
//                MSP430F261x
//             -----------------
//         /|\|              XIN|-
//          | |                 | 32kHz
//          --|RST          XOUT|-
//            |                 |
//            |        DAC0/P6.6|--> ~ 1kHz sine wave
//            |                 |
//
//   B. Nisarga
//   Texas Instruments Inc.
//   September 2007
//   Built with CCE Version: 3.2.0
//******************************************************************************
#include "msp430x26x.h"

//-------------------------------------------------------------------------------
// 12-bit Sine Lookup table with 32 steps
//-------------------------------------------------------------------------------

const 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)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog timer
  ADC12CTL0 = REFON;                        // Internal reference
  DMA0SA = (void (*)())Sin_tab;             // Source block address
  DMA0DA = (void (*)())&DAC12_0DAT;         // Destination single address
  DMA0SZ = 0x020;                           // Block size
  DMACTL0 = DMA0TSEL_5;                     // DAC12IFG trigger
  DMA0CTL = DMADT_4 + DMASRCINCR_3 + DMAEN; // Rpt, inc src, word-word
  DAC12_0CTL = DAC12LSEL_2 + DAC12IR + DAC12AMP_5 + DAC12IFG + DAC12ENC;
  TACCTL1 = OUTMOD_3;                       // TACCR1 set/reset
  TACCR1 = 01;                              // TACCR1 PWM Duty Cycle
  TACCR0 = 032-1;                           // Clock period of TACCR0
  TACTL = TASSEL_2 + MC_1;                  // SMCLK, contmode
  __bis_SR_register(LPM0_bits + GIE);       // Enter LPM0
}