STM8S105S4 I2C

After successfully transmitting the correct data once, I can't enter. The program is still running normally

#define I2CAddr 0x01
in the host
  //The host writes data, and the slave receives it. This does not work.
   Soft_I2C_Start();
    Soft_I2C_Write(0x02);
    Soft_I2C_Write(0xAA);
    Soft_I2C_Stop();
    //The host receives data. Without running the previous program, the host can receive data. Running the previous program, the data received by the host is 255.
    Soft_I2C_Start();
    Soft_I2C_Write(0x03);
    var0=Soft_I2C_Read(1);
    Soft_I2C_Stop();
    This soft I2C has no problem controlling other devices. The chip used by the host is STM32. There should be no problem.

 Solve the problem:

That's it. After you succeeded for the first time, if you turned off the response, how can you still receive it? You should be more careful when configuring the register in the future.

1. PC0, PC1 initialization, GPIO_Init(GPIOC, GPIO_Pin_1 | GPIO_Pin_0, GPIO_Mode_Out_OD_HiZ_Fast);
2. Hardware must be connected
3. The bus cannot be busy, it must be idle
The initialization code is as follows:
GPIO_Init(GPIOC, GPIO_Pin_0, GPIO_Mode_Out_OD_HiZ_Slow);
                GPIO_Init(GPIOC, GPIO_Pin_1, GPIO_Mode_Out_OD_HiZ_Slow);
                CLK_PeripheralClockConfig(CLK_Peripheral_I2C1, ENABLE);
                I2C_Init(I2C1, 50000, 0xA5, I2C_Mode_I2C, I2C_DutyCycle_2,
           I2C_Ack_Enable, I2C_AcknowledgedAddress_7bit);
//Note: I2C is already enabled in I2C_Init(), so I2C_Cmd(I2C1, ENABLE);
                while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));

The built-in I2C of stm8 was finally debugged successfully.

1. This debugging of I2C has benefited me a lot. First of all, it proves that the official program for writing EEPROM is correct.
2. The reason why the debugging of TW8816 failed at the beginning was that I mistakenly thought that the register address was 16 bits (the chip company's business also said so, and I believed it), which made me see different data, but I think that there is data, and the program runs through using the WHILE waiting method, which means that it is connected to the slave.
3. Do not configure the GPIO of I2C. I saw some colleagues configure the GPIO.
4. In order for everyone to use the I2C of STM8 well, I baked the program.

void IIC_Init(void)
{
        UCHAR temp;
        
        CLK_PCKENR1 |= 0x01;

        I2C_FREQR |= 0x10; //Input peripheral clock frequency is 1MHz
        I2C_CR1 = 0x00; //Disable I2C peripherals
        I2C_CCRH &= ~0xcf;
        I2C_CCRL &= ~0xff;  
  I2C_TRISER = 0x11;
        I2C_CCRL = 0x10;
        I2C_CCRH = 0x00;
        I2C_CR1 |= 0x01; //Enable I2C peripherals
        I2C_CR2 |= 0x04; //Current received byte returns response
        I2C_CR2 &= 0x08;
        I2C_OARL = 0x86; //Own address
        I2C_OARH = 0x40;
}

void Read_8816(UCHAR *pBuffer, UCHAR index, UCHAR NumByteToRead)
{
        UCHAR temp;

        while(I2C_SR3 & 0x02); //Wait for bus to be free
        I2C_CR2 |= 0x01; //Generate start bit
        while(!(I2C_SR1 & 0x01)); //Wait for START to be sent
        I2C_DR = 0x8a; //Send 8816 device address
        while(!(I2C_SR1 & 0x02)); //Wait for special 7-bit device address to be sent
        temp = I2C_SR1;
        temp = I2C_SR3;
        I2C_DR = (UCHAR)(index);
        while(!(I2C_SR1 & 0x84));
        
        I2C_CR2 |= 0x01; //Generate repeated start bit
        while(!(I2C_SR1 & 0x01)); //Wait for START to be sent
        I2C_DR = 0x8b; //Read
        while(!(I2C_SR1 & 0x02)); //Wait for the 7-bit device address to be sent
        temp = I2C_SR1;
        temp = I2C_SR3;
        while(NumByteToRead) //How many bytes to read
        {
                if(NumByteToRead == 1)
                {
                        I2C_CR2 &= ~0x04; //Do not return a response
                        I2C_CR2 |= 0x02; //Generate a stop bit
                }
                if(I2C_SR1 & 0x40)
                {
                        temp = I2C_SR1;
                        Buff[8-NumByteToRead]=I2C_DR;
                        *pBuffer = Buff[8-NumByteToRead];
                        pBuffer++;
                        NumByteToRead--;
                }
        }
        I2C_CR2 |= 0x04;
        I2C_CR2 &= ~0x08; //Enable response for the next receive
}