dac8831.c

449的程序430Interfacing the DAC8831EVM to MSP430 Processors

/****************************************************************/
/* FILENAME: main.c                            		        */
/* DESCRIPTION: This program uses the MSP430F449 to write 256 	*/
/*    samples to the DAC8531 EVM board.                         */  
/*    The samples are generated by sine/cosine functions        */  
/*    AUTHOR: T. Hendrick, Data Acquisition Products,           */  
/*            Dallas Texas                                      */
/*    CREATED 2005(C) BY TEXAS INSTRUMENTS INCORPORATED.  	*/
/*    VERSION: 01 						*/
/* Compiled on IAR Embedded Workbench V 3.0B; IAR C-Compiler    */
/* for MSP430 V2.21B-P1/W32 [Kickstart]                         */
/****************************************************************/
#include <msp430x44x.h>
#include <math.h>
#include "SBLCDA2.h"

/**************** Function prototypes ***********************************/
/*                                                                      */
void init_sys(void);                /* MSP430 Initialisation routine    */
void setupClock(int);
void delay(int);                   /* Software delay                   */
void dac_convert(int);             /* Do the adc conversion            */
void display(void);                 /* Indicate Program complete        */
void InitializeLCD( void );
void clearDisplay( void );
void sortMajor( unsigned int );
void displaySpecial( long int );
void displayMinor( int, int );
void displayHPA449(void);
void displayTest(void);	
void InitTables(int);

/************************************************************************/
/*                                                                      */
/* HPA449 variable declarations                                         */
/*                                                                      */            
/************************************************************************/
#define DAC_CS       0x20  //p3.5
#define Resonator (0)
  
/************************************************************************/
/*                                                                      */
/* main() variable declarations                                         */
/*                                                                      */
/************************************************************************/
#define BLOCK_SZ  256/* size of data buffer */
#define TABLE_SIZE       256

int sinetable[TABLE_SIZE], costable[TABLE_SIZE], byte0, byte1;
int i, y;

/******************************************************************************\
* Function: InitTables()
* Description: Initializes Sine and Cosine Values 
\******************************************************************************/
void main(void)
{

  setupClock(Resonator);
  init_sys();                   	// Initialise the MSP430       
  InitializeLCD();       
  clearDisplay();
  displaySpecial(SoftBaugh|AL|AR|AU|AD);
  InitTables(4);                                
         displayTest();
         displaySpecial(SoftBaugh|AR);  
      do {
           for(i=0; i<BLOCK_SZ; i++)
           {
            dac_convert(sinetable[i]);  // Send sine values to the DAC
           }
         } 
       while (1);              // Endless Loop
}			      	

void InitTables(int period)
{         
	int y;
	for (y = 0; y < TABLE_SIZE; y++)
	{
	  sinetable[y] = (unsigned int)((sin(2 * 3.141593659 * period * y / TABLE_SIZE) + 1.0) * 32767);
	  costable[y] = (unsigned int)((cos(2 * 3.141593659 * period * y / TABLE_SIZE) + 1.0) * 32767);
	}
}

/************************************************************/
/* Prototype - init_sys                                     */
/*                                                          */
/*  Description                                             */
/*  This prototype initialises the MSP430F149               */
/************************************************************/
void init_sys(void)
{
void setupports(void);  /* Local function prototype         */
void setupSPI(void);    /* Local function prototype         */    

setupports();
setupSPI();
  _EINT();                              // Enable interrupts
}

/************************************************************/
/* Prototype - setupClock                                     */
/*                                                          */
/*  Description                                             */
/*  This prototype sets-up the XT2 oscillator and tests     */
/*  that it has settled before moving on                    */
/************************************************************/      
void setupClock (int RES)
{
    switch (RES)
    {
        case  0:
          { WDTCTL = WDTPW + WDTHOLD;
            /* D=2, N=121, no mod */
            SCFQCTL=121;
            // SCFI0 = 0100 0100
            SCFI0=0x44;
            // DCOPLUS=1, XTS_FLL=0
            // XCAPXPF=00
            FLL_CTL0=0x80;
            // SMCLK=0, XT2OFF=1, SELMX=00, SELS=0, FLL_DIVX=10
            // FLL_CTL1= 0010 0010
            FLL_CTL1=0x22;
          }
          break;        
        case  1:
          { WDTCTL = WDTPW + WDTHOLD;           // Stop watchdog timer  
            FLL_CTL0&=XT2OFF;                    // Switch on the XT2 osc.
            FLL_CTL1|=SELM_XT2+SELS;                // Select XT2 osc. for 
            // Test the osc. flag bit
            do {
                IFG1 &= ~OFIFG;            // Clear the OFIFG bit
                } while (OFIFG&IFG1);      //
          }
          break;
    }    
}                           

/************************************************************/
/* Prototype - setupports                                   */
/*  Description                                             */
/*  This prototype sets-up the GPIO ports as appropriate    */
/************************************************************/      
void setupports (void)
{
// SPI port for ADC
P3SEL = BIT3 + BIT2 + BIT1;                 // Bits 3, 2 & 1 are assigned as SPI specific pins
P3DIR = DAC_CS;                           // Set the ADC_CS bit as an output
P3OUT = DAC_CS;                           // De-assert ADC_CS for the adc - HIGH
P4SEL = BIT5 + BIT3 + BIT2;

//SetupInterrupts
P1IFG |= 0x00;
P1IES |= 0x40;
P1IE |= 0x40;
}

/************************************************************/
/* Prototype - setupSPI                                     */
/*                                                          */
/*  Description                                             */
/*  This prototype sets-up the P3 for communication via SPI */
/************************************************************/      
void setupSPI (void)

/************************************************************/
/* System definitions                                       */
/************************************************************/
#define     SPI0en       0x40
#define     SPI1en       0x10

{    
ME1 |= USPIE0;                      // Module Enable - SPI1
U0CTL &= ~SWRST;                    // Make sure the RESET bit is off                                   
U0CTL |= CHAR + SYNC + MM;          // USART0 module operation
                                    // CHAR = 1 => 8-bit data 
                                    // SYNC = 1 => SPI selected
                                    // MM = 1 => master mode,
U0TCTL |= CKPH + SSEL0 + SSEL1 + STC;      // USART0 Tranmit control register
U0BR0  = 0x02;                      // Divide SMCLK by 2 => transfer clock
U0BR1  = 0x00;                      //
U0MCTL = 0x00;                      // Modulation control - not used. Ensure 
                                    // all these bits are reset
}

/************************************************************/
/* Prototype - delay                                        */
/*  Description                                             */
/*  This prototype gives a delay of around 1 second         */
/************************************************************/

void delay(int time)
      {
      unsigned int i;
      for (i = 0; i < time; i++);
      }  

/************************************************************/
/* Prototype - convert                                      */
/*  Description                                             */
/*  This prototype does the DAC conversion                  */
/************************************************************/      
void dac_convert (value)
{
byte0 = value >>8;
byte1 = value >>0;

P3OUT &= ~(DAC_CS);                // Set DAC /CS low
while ((IFG1 & UTXIFG0) == 0);
      U0TXBUF = byte0;             // Send clocks to the DAC, this shifts 1st byte 
	                           // Wait until all 8 bits have been received.
while ((IFG1 & UTXIFG0) == 0);
      U0TXBUF = byte1 ;            // Send clocks to the DAC, this shifts 2nd byte 
	                           // Wait until all 8 bits have been received.
P3OUT |= (DAC_CS);                 // Set DAC /CS high
}

/************************************************************/
/* Prototype - displayTest                                  */
/*  Description                                             */
/*  This function displays "8831" on the LCD Screen         */
/************************************************************/
void displayTest(void)
{
    displayMinor(5,UL_EIGHT);
    displayMinor(4,UL_EIGHT);
    displayMinor(3,UR_THREE);
    displayMinor(2,UR_ONE);
}