fet430_dma_02.c

msp430开发c语言例程

//******************************************************************************
//  MSP-FET430P430 Demo - DMA0 Repeated Block To P1OUT, TACCR2, DCO
//
//  Description; DMA0 is used to transfer a string byte-by-byte as a repeating
//  block to P1OUT. Timer_A operates continuously with CCR2IFG 
//  triggering DMA0. The effect is P5.1/5.2 toggling at different frequencies. 
//
//               MSP430FG439
//            -----------------
//        /|\|              XIN|-  
//         | |                 |
//         --|RST          XOUT|-
//           |                 |
//           |             P5.1|--> LED 
//           |             P5.2|--> 
//
//  M.Buccini
//  Texas Instruments, Inc
//  June 2004
//  Built with IAR Embedded Workbench Version: 2.21B
//******************************************************************************

#include  <msp430xG43x.h>

const unsigned char testconst[] = { 0x00, 0x06, 0x04, 0x06, 0x00, 0x02 };

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                           // Stop watchdog
  P5DIR |= 0x06;                                      // P5.1/5.2 output 
  DMACTL0 = DMA0TSEL_1;                               // CCR2IFG trigger
  DMA0SA = (unsigned int)testconst;                   // Source block address
  DMA0DA = P5OUT_;                                    // Dest single address
  DMA0SZ = sizeof testconst;                          // Block size
  DMA0CTL = DMADT_4 + DMASRCINCR_3 + DMASBDB + DMAEN; // Rpt, inc src, enable
  TACTL = TASSEL_2 + MC_2;                            // SMCLK, cont-mode
       
  _BIS_SR(LPM0_bits);                                 // Enter LPM0
}