STM8S 模拟I2C程序

STM8S的硬件I2C还是存在问题,不敢贸然使用.

于是决定用模拟I2C.

#define SCL              PE_ODR_ODR1
#define SDA              PE_ODR_ODR2
#define SDAM             PE_IDR_IDR2
#define SET_SCL_OUT()    {PE_DDR_DDR1=1; PE_CR1_C11 = 1; PE_CR2_C21 = 0;}
#define SET_SDA_OUT()    {PE_DDR_DDR2=1; PE_CR1_C12 = 1; PE_CR2_C22 = 0;}
#define SET_SDA_IN()     {PE_DDR_DDR2=0; PE_CR1_C12 = 0; PE_CR2_C22 = 0;}
//--------------------------------------------------------------
// Prototype      : void I2C_Start(void)
// Calls          : Delay_5us()
// Description    : Start Singnal
//--------------------------------------------------------------
void I2C_Init(void)
{
   I2C_CR1 &= 0xFE;      //  PE=0, disable I2C module
   SET_SCL_OUT();
   SET_SDA_OUT();
}

//--------------------------------------------------------------
// Prototype      : void Delay_5us(void)
// Description    : 大约延时5us
//--------------------------------------------------------------
void Delay_5us(void)
{
   uchar i;                   //fcpu 8MHz 时
   ; i>; i--);
}

//--------------------------------------------------------------
// Prototype      : void I2C_Start(void)
// Calls          : Delay_5us()
// Description    : Start Singnal
//--------------------------------------------------------------
void I2C_Start(void)
{
    // SDA 1->0 while SCL High
    SDA = ;
    SCL = ;
    Delay_5us();
    SDA = ;
    Delay_5us();
    SCL = ;
}

//--------------------------------------------------------------
// Prototype      : void I2C_Stop(void)
// Calls          : Delay_5us()
// Description    : Stop Singnal
//--------------------------------------------------------------
void I2C_Stop(void)
{
    // SDA 0->1 while SCL High
    SDA = ;
    SCL = ;
    Delay_5us();
    SDA = ;
    Delay_5us();
}

//--------------------------------------------------------------
// Prototype      : void I2C_SendACK(uchar ack);
// Calls          : Delay_5us()
// Parameters     : bit ack:1-noack, 0-ack
// Description    : Master device send ACK to slave device.
//--------------------------------------------------------------
void I2C_SendACK(uchar ack)
{
    )
    {
      SDA = ;
    }
    else
    {
      SDA = ;
    }

    SCL = ;
    Delay_5us();  

    SCL = ;
    Delay_5us();
}

//--------------------------------------------------------------
// Prototype      : uchar I2C_SendByte(uchar sendDAT)
// Calls          : Delay_5us()
// Parameters     : uchar sendDAT---data to be send
// Return Value   : CY--slave ack (1---noack，0---ack)
// Description    : Send one byte to I2C
//--------------------------------------------------------------
uchar I2C_SendByte(uchar sendDAT)
{
    uchar i,revack;

     ; i< ; i++)
    {
     SCL = ;
     Delay_5us();  

 if (sendDAT & 0x80)             // write data
 {
       SDA = ;
 }
      else
 {
         SDA = ;
 }

        sendDAT <<=  ;

        SCL = ;
        Delay_5us();
    } 

   SCL = ;
   Delay_5us();  

   SET_SDA_IN();

   SCL = ;
   asm("nop");
   asm("nop");

   revack = (uchar)SDAM;

   Delay_5us();
   SCL = ;   

   SET_SDA_OUT();

   Delay_5us();  

   return revack;
}

//--------------------------------------------------------------
// Prototype      : uchar I2C_RecvByte()
// Calls          : Delay_5us()
// Parameters     : none
// Return Value   : revDAT- received data
// Description    : Receive one byte from I2C
//--------------------------------------------------------------
uchar I2C_RecvByte()
{
    uchar i;
    uchar revDAT = ;

    SDA = ;     // latch the Data port befor reading

    SET_SDA_IN();

    ; i<; i++)
    {
       revDAT <<= ;

       SCL = ; 

       asm("nop");
       asm("nop");

       if (SDAM)
       {
          revDAT |= 0x01;
       }
       else
       {
   revDAT &= 0xfe;
       }

       Delay_5us();
       SCL = ;
       Delay_5us();
    }

   SET_SDA_OUT();

   return revDAT;
}

//--------------------------------------------------------------
// Prototype      : void Write_PT2314(uchar wdata)
// Calls          : I2C_Start(), I2C_Stop(),I2C_SendByte()
// Parameters     : RegAddr-- target memory address,
//                  wrdata--- data to be writing
// Description    : Write one byte to target memory
//--------------------------------------------------------------
void Write_24c02(uchar regadd,uchar wdata)
{
    I2C_Start();
    I2C_SendByte(0xA0);     // Device Addr + Write (operation)
    I2C_SendByte(regadd);
    I2C_SendByte(wdata);
    I2C_Stop();
}

uchar Read_24c02(uchar regadd)
{
    uchar revdata;

    I2C_Start();
    I2C_SendByte(0xA0);     // Device Addr + Write (operation)
    I2C_SendByte(regadd); 

    I2C_Start();
    I2C_SendByte(0xA1);     // Device Addr + Write (operation)   

    revdata = I2C_RecvByte();
    I2C_SendACK();

    I2C_Stop();   

    return revdata;
}