//******************************************************************************
//  MSP-430-Day II Demo - DMA0 Repeated Block UART0 9600, TBCCR2, ACLK
//
//  Description; DMA0 is used to transfer a string byte-by-byte as a repeating
//  block to U0TXBUF. Timer_B operates in 12-bit mode at 32768Hz with TBCCR2IFG 
//  triggering DMA0. "Hello World" is TX'd via 9600 baud UART0.
//  ACLK = TBCLK = 32768 = UCLK, MCLK = SMCLK = default DCO =1048576
//  Baud rate divider with 32768hz XTAL @9600 = 32768Hz/9600 = 3.41 (000Dh 4Ah )
//  //*An external watch crystal on XIN XOUT is required for ACLK*//	  
//  //*MSP430FG439 Device Required*//
//
//               MSP430FG439
//            -----------------
//        /|\|              XIN|-  
//         | |                 | 32KHz
//         --|RST          XOUT|-
//           |                 |
//           |             P2.4|------------> "Hello World"
//           |                 | 9600 - 8N1
//
//  M.Buccini
//  Texas Instruments, Inc
//  February 2004
//  Built with IAR Embedded Workbench Version: 2.21B
//******************************************************************************

#include <msp430xG43x.h>

static char string1[] = { "Hello World\r\n" };

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                   // Stop watchdog
  FLL_CTL0 |= XCAP14PF;                       // Set load capacitance
  P2SEL = 0x30;                               // P2.4,5 = USART0 TXD/RXD
  ME1 |= UTXE0;                               // Enabled UART0 TXD
  U0CTL |= CHAR;                              // 8-bit char, SWRST=1
  U0TCTL |= SSEL0;                            // UCLK = ACLK
  U0BR0 = 0x03;                               // 9600 from 32768Hz
  U0BR1 = 0x00;
  U0MCTL = 0x4A;                              // Modulation
  U0CTL &= ~SWRST;                            // Enable USART

  DMACTL0 = DMA0TSEL_2;                       // TBCCR2IFG
  DMA0SA = (unsigned int)string1;             // Source block address
  DMA0DA = U0TXBUF_;                          // Dest single address
  DMA0SZ = sizeof string1-1;                  // Block size
  DMA0CTL = DMADT_4 + DMASRCINCR_3 + DMASBDB + DMAEN;// Rpt, inc src, enable
  TBCTL = CNTL_1 + TBSSEL_1 + MC_2;             // 12-bit, ACLK, cont-mode
        
  _BIS_SR(LPM3_bits + GIE);                    // Enter LPM3 w/ interrupt
}