24c01-512.c

来自「读写24C512/256」· C语言 代码 · 共 185 行

#include "msp430x13x.h" 
   		
void nop(void)
{
  _NOP();
  _NOP();
  _NOP();
}

void start(void)   		 
{
  SCLEN &= (~(SDA+SCL));	
  _NOP();
  _NOP();
  _NOP();  
  SDAEN |= SDA; 		
  SCLEN |= SCL;	   		
  return;
}
void stop(void)
{
  SDAEN |= SDA;         	
  SCLEN &= (~SCL);		
  SDAEN &= (~SDA);		
  return;
}


unsigned char ControlByte(int AddressByte)
{
  unsigned char temp;

  _BIC_SR(0X0001);		//CLEAR SR 'C'
  temp = (char)(AddressByte>>8);
  temp <<= 1 ;
  temp &= 0X0E;
  temp += Code;
  return temp;
}


int shout( unsigned char data )  
{
 unsigned char mask,i,temp;
 unsigned char Value;

 Value = data;
 mask=0X80;

 for (i=0;i<=7;i++){ 

      temp = (Value & mask);        
      if( temp !=0 ){		
          SDAEN &=  (~SDA);	
          SCLEN &=  (~SCL);	
         if( !( SDAIN & SDA ) ){
            return 1;
          }
      }
      else {
        SDAEN |= SDA ; 		
        SCLEN &= (~SCL);	
      }
    
    mask>>=1;

    SCLEN |= SCL; 			
 }
  SDAEN &= (~SDA); 
  SCLEN &= (~SCL);

  if ( !(SDAIN & SDA )){
     // return 1;
  }
  
  SCLEN |= SCL;
  return 0;
}

// 写 Number 个字节到 E2 中 
int WriteBlock(int number,unsigned char *dataadr,unsigned char *e2adr)
{
  unsigned char *p1;
  int i;
  unsigned char temp;
  unsigned int aaa;
  //unsigned char *temp1;
  
  _DINT();			
  SDADAT &= (~(SCL+SDA));	
  				
  start();                      

  aaa = (int)(e2adr );
  temp = ControlByte(aaa);
  shout(temp);

  shout( (int)(e2adr));

  p1 = dataadr; 

  for (i=1;i<=8;i++) {

     shout(*p1);
     p1++;
  }
  stop();	
  _EINT();	
 
//Write a block use the address and back..
 return 0;          			//if error return 1  right return 0
}
// 写N * 8个字节 
int WriteN8Byte(int Number)
{
  unsigned char *e2adr,*dataadr;
  unsigned int i,j;

//int WriteBlock(int number,unsigned char *dataadr,unsigned char *e2adr)
  dataadr = (char*)0x200;
  e2adr = (char*)0x00;

  for( i=1;i<=Number;i++){
  
    WriteBlock(8,dataadr,e2adr);
    dataadr += 8;  
    e2adr += 8;    
    for (j=0;j<=3333;j++);            
    
  }

  return 0;
}

//; Clock out an acknowledge bit (low).
//; SCL expected low on entry. Return with SCL, SDA low.
void Ack(void)
{
  SDAEN |= SDA;
  SCLEN &= ~SCL;
  SCLEN |= SCL;
  
}
//; Clock out a negative acknowledge bit (high).
//; SCL expected low on entry. Return with SCL low, SDA high.
void Nak(void)
{
  SDAEN &= ~SDA;                    //; NAK bit
  SCLEN &= ~SCL;                    //; raise clock
  SCLEN |= SCL;                     //; drop clock

}
//由E2 中 读8位 一个字节 数据
unsigned char shin(void)
{
  int i;
  unsigned char temp;
  unsigned char Mask;

  SDAEN &= ~SDA;                  // make SDA an input
  temp =0;

//读8位数据
  for( i=1;i<=8;i++) {
    
    SCLEN &= ~SCL;                //SCL = H
    Mask = 0;

    if (SDAIN &SDA)
      Mask = 1;
    else
      Mask =0;
//    Mask = SDAIN & SDA;
    Mask <<= (8 - i);
    temp ^= Mask;
    SCLEN |= SCL;    
  }

  return temp;
 }
// 24c256 512 页 64字节 14-15bit Word Address!!!
//**********************************************************************
//  读取N 个字节 到RAM 中
//  参数说明： number 读取的个数，dataadr,读到RAM 的地址