p87lpc769_ad.c

Philips系列单片机P87LPC769_AD .c

//Philips P87LPC767/768/769 A/D Example Program

#include <REG767.H>
#include <stdio.h>

#define VREF    5				  /* Voltage Reference */


void main (void)
{

/* Disable Digital Output and Input */
PT0AD =  0x78;            /* Disable Digital Inputs on A/D input pins   */
P0M1 =  0x87;			        /* Disable Digital Outputs on A/D input pins  */

/* Init ADC	 */
ENADC = 1;				        /* Enable ADC                                 */
RCCLK = 0;		      		  /* Use CPU clock as A/D clock                 */ 

/* initialize the serial interface */
SCON  = 0x50;			        /* SCON: mode 1, 8-bit UART, enable rcvr      */ 
TMOD |= 0x20;	      		  /* TMOD: timer 1, mode 2, 8-bit reload        */
TH1  =  0xFB;			        /* TH1: reload value for 19200 baud           */
TR1   = 1;			      	  /* TR1: timer 1 run                           */
TI    = 1; 			          /* TI: set TI to send first char of UART      */

/* Perform conversions forever */
while (1){
  
  WDRST = 0x1E;			      /* Reset Watchdog Timer                       */
  WDRST = 0xE1;	    		  /* Reset Watchdog Timer                       */																	   
  ADCI = 0;               /* Clear conversion status                    */
  ADCS = 1;               /* Start conversion                           */

  while (ADCI == 0);      /* Wait for conversion                        */

/* Read A/D data and print it out */
  printf ("DAC0 Value %4u = %01u.%04u Volts\r",
         (unsigned) DAC0,
         (unsigned) (DAC0 * VREF) >> 8,                          /* Output Integer Portion */
         (unsigned) ((DAC0 * VREF * 10000UL) >> 8UL) % 10000);   /* Output Decimal Portion */
 

  }											
}