dac.c

DSP2407控制程序

/*--------------------------------------------------------*/
/*  SPECTRUM DIGITAL INC.				                  */
/*--------------------------------------------------------*/
/*  Offchip DAC test for EVM320LF2407			          */
/*  This test requires a loopback connector		          */
/*--------------------------------------------------------*/
/*							                              */
/*  filename:	 dac.c					                  */
			          
/*  last update: 08/18/2005   by: LYP for 2407		      */
/*--------------------------------------------------------*/

#include "dac.h"
#include "LF2407REGS.h"
#define MS_TIME_LOOP   0x0385
volatile unsigned int dacdata;
#define MAX_DAC     4
unsigned int wait_ms( volatile unsigned int delay_val )//延时1ms程序
{
    unsigned int i;
    unsigned int ms_ctr;
    for ( i = 0; i < delay_val; i++ )
    {
	ms_ctr = MS_TIME_LOOP;

	while ( ms_ctr )
	{
	    ms_ctr--;
	}
    }

    return( delay_val );
}

void write_dac(unsigned int dac_num, unsigned int dac_val) //往DA通道写数
{
  unsigned int write_dac_status;

  if ( dac_num < MAX_DAC )
  {
    dacdata = dac_val;                /* put in global location */

    switch (dac_num)
    {
      case DAC0:
        OUTMAC( _DAC0, dacdata);                  
        break;

      case DAC1:
        OUTMAC( _DAC1, dacdata);                  
        break;

      case DAC2:
        OUTMAC( _DAC2, dacdata);                  
        break;

      case DAC3:
        OUTMAC( _DAC3, dacdata);                  
        break;

    }

    asm("    nop" );
    asm("    nop" );
    asm("    nop" );
    asm("    nop" );
    asm("    nop" );
    asm("    nop" );


    OUTMAC( _DAC_XFER, dacdata);      /* just need a write, any data */
  }

}


void initsys(){
  asm(" setc SXM ");
  asm(" clrc OVM ");
  asm(" clrc CNF ");

  *SCSR1=0x83fe;  
  *WDCR =0x0e8;
  *IMR  =0x000f;
  *IFR  =0xffff;
  *WSGR =0x00;

}  

void inline disable(){
asm(" setc INTM ");
}

void inline enable(){
asm(" clrc INTM ");
}
void interrupt nothing()
{return;}


void main() //程序输出方波，周期200ms
{ 
 disable();
  initsys();
  while(1)
   {write_dac(0,4090);write_dac(1,4090);write_dac(2,4090);write_dac(3,4090);
    wait_ms(100);
    write_dac(0,0);write_dac(1,0);write_dac(2,0);write_dac(3,0);
    wait_ms(100);};

}