main.c

用VC编辑的一个MD5算法

#include "ddsapi.h"
#include "table.h"
#include "exchange.h"
#include <stdlib.h>

 
#define SB(var, num) *(((BYTE*)&var)+num)
#define SIGN_BIT 0x08
#define QUATER_BIT 0x04
#define TABLE_MASK 0x03FF

#define FREQ_MULT 4295
#define INIT_FREQ 1000
#define MAX_FREQ  30000

extern volatile BOOL ready;
extern char rx_buffer[];

static DWORD accum = 0, dphase = INIT_FREQ*FREQ_MULT;
static WORD adr = 0;
static BYTE msb, lsb;
 
#pragma  ioport   DAC_MSB_CR0:   0x080
BYTE              DAC_MSB_CR0;

#pragma  ioport   DAC_LSB_CR0:   0x090  
BYTE              DAC_LSB_CR0;
//you must change these values accordingly to your DAC9 placement,
//alternatively you can use the fixed version of the DAC_WriteStall2B()

void main()
{
  DAC_Start(DAC_FULLPOWER);
  PGA_FIL1_Start(PGA_FIL1_HIGHPOWER);
  PGA_FIL2_Start(PGA_FIL2_HIGHPOWER);
  PGA_OUT_Start(PGA_OUT_HIGHPOWER);
  SPIS_Start(SPIS_LSB_FIRST);
  
  PGA_FIL2_GAIN_CR1 |= 0x40;
  PGA_FIL2_GAIN_CR2 &= ~0x40;
  //enable comparator bus and disable the output latch
  // but comparator bus is column clock synchronized still
  
  OpenExchange();
  M8C_EnableGInt;
  
  ExchangeSend("The DDS generator is ready.\n\r");
  
  while(1)
  { 
    msb = strlen(rx_buffer)-2;
    switch (rx_buffer[msb])
    {
      case 'f':
      case 'F':
        rx_buffer[msb] = 0;
        dphase = FREQ_MULT*atof(rx_buffer);
        ExchangeSend("The frequency was set well.\n\r");
      break;
      
      case 'g':
      case 'G':
        rx_buffer[msb] = 0;
        lsb = atoi(rx_buffer);
        if (lsb < GAIN_LEVELS) 
        {
          PGA_OUT_SetGain(gain_table[lsb]);
          ExchangeSend("The gain was set well.\n\r");
         }
      break;
      
      default:
      break;
    }
   
    ready = TRUE;
    
    while(ready)
    {
      accum += dphase;
      SB(adr,0) = SB(accum,0);
      SB(adr,1) = SB(accum,1);
      if (SB(accum,0) & QUATER_BIT) adr ^= 0xFFFF;
      adr &= TABLE_MASK;
     
      msb = lsb = sin_table[adr];
      
      msb >>= 3;
      msb |= 0x80;
      
      lsb &= 0x07;
      lsb <<= 2;
      lsb  |= 0x80;
      
      if (SB(accum,0) & SIGN_BIT) 
        msb |= 0x20;
      else 
        lsb |= 0x20;
        
    M8C_Stall;
    DAC_MSB_CR0 = msb;
    M8C_Unstall;
    DAC_LSB_CR0 = lsb;    
    //instead it, the fixed version DAC_WriteStall2B(lsb, msb) can be used
    //but you have less time reserve
   }
     
 }  
}