iicfor430.c

一个模拟IIC程序

#include <MSP430x14x.h>
//#include "SysType.h"
#include "CLKReadWrite.h"

//作者：卢益贵 2008-1-8 上传 QQ：48092788

#define SCL                  0x04   /* P2.1 */
#define	SDA                  0x02   /* P2.2 */

#define ADDR_I2CWRITE        0x64
#define ADDR_I2CREAD         0X65
#define ADDR_I2CSECOND       0X00

void InitCLK(void)
{
    P2SEL &= ~(SCL | SDA);
    P2DIR |= SCL;
    P2DIR &= ~SDA;
    P2OUT |= SCL;
    CLKInit();
}

void Delay(unsigned char bLong)
{
    while(bLong)
        bLong--;
}

void I2CStart( void ) 
{
  Delay( 0 );
  P2OUT |= SDA; 
  Delay( 0 );
  P2OUT |= SCL; 
  Delay( 0 );
  P2OUT &=~ SDA;
  Delay( 0 );
  P2OUT &=~ SCL;
  Delay( 0 );
}
 
void I2CStop( void ) 
{
  Delay( 0 );
  P2OUT &=~ SDA;
  Delay( 0 );
  P2OUT |= SCL;
  Delay( 0 );
  P2OUT |= SDA;
  Delay( 0 );
}

void I2CAck( void ) 
{
  Delay( 0 );
  P2OUT &=~ SDA; 
  Delay( 0 );
  P2OUT |= SCL;  
  Delay( 0 );
  P2OUT &=~ SCL; 
  Delay( 0 );
}

void I2CNoAck( void ) 
{
  Delay( 0 );
  P2OUT |= SDA;  
  Delay( 0 );
  P2OUT |= SCL;  
  Delay( 0 );
  P2OUT &=~ SCL; 
  Delay( 0 );
}

void I2CTestAck( void ) 
{
  Delay( 0 );
  P2DIR &=~SDA;  
  Delay( 0 );
  P2OUT |= SCL;  
  Delay( 0 );
  P2DIR |=SDA;  
  Delay( 0 );
  P2OUT &=~ SCL;
  Delay( 0 );
}

void I2CWrite( unsigned char Data )
{
  auto unsigned char i;
  for( i = 8 ; i != 0 ; i--)
  {
    if ( Data & 0x80 )
      P2OUT |= SDA;
    else
      P2OUT &=~ SDA;
    P2OUT |= SCL;
    Delay( 0 );
    P2OUT &=~ SCL;
    Delay( 0 );
    Data = Data << 1;
  }
}

unsigned char I2CRead( void ) 
{
  auto unsigned char i , Result = 0;
  P2DIR &=~SDA;
  for( i = 8 ; i != 0 ; i-- ) 
  {
    P2OUT |= SCL;
    Result = Result << 1;
    Delay( 0 );
    if ( ( P2IN & SDA ) == SDA )
      Result = Result | 0X01;
    P2OUT &=~ SCL;
    Delay( 0 );
  }
  P2DIR |= SDA;
  return( Result );
}

void CLKInit( void )
{
  I2CStart();
  I2CWrite( ADDR_I2CWRITE );
  I2CTestAck();
  I2CWrite( 0xe0 ); 
  I2CTestAck();              
//  I2CWrite( 0xc3 );
    I2CWrite( 0x00 );
  I2CTestAck();
  I2CWrite( 0x20 ); 
  I2CTestAck();
  I2CStop();
}


void SetDateTimeCLK( unsigned char *DT ) 
{
  auto unsigned char i = 6;
  
  I2CStart();
  I2CWrite( ADDR_I2CWRITE );
  I2CTestAck();
  I2CWrite( ADDR_I2CSECOND );
  I2CTestAck();
  I2CWrite( *DT + *( DT+ 7 ) );
  DT++;
  I2CTestAck();
  while( i > 0 ) 
  {
    I2CWrite( *DT++ );
    I2CTestAck();
    i--;
  }
  I2CStop();
}

void GetDateTimeCLK( unsigned char *DT )
{
  auto unsigned char i = 0;
  I2CStart();
  I2CWrite( ADDR_I2CWRITE );
  I2CTestAck();
  I2CWrite( ADDR_I2CSECOND );
  I2CTestAck();
  I2CStart();
  I2CWrite( ADDR_I2CREAD );
  I2CTestAck();
  while( i < 7 ) 
  {
    *DT = I2CRead();
    *DT++ = ( *DT >> 4 ) * 10 + *DT % 16;
    I2CAck();
    i++;
  }
  *DT = I2CRead();
  I2CNoAck();
  I2CStop();
}