【Blue Bridge Cup MCU】AT2C02 EEPROM

This is also the iic bus structure!

Here is a summary of the program structure of iic

Read and write operations in the same function (taking reading eeprom as an example)

(1) Open the bus

(2) Write address word and wait for response (write command)

(3) Write the address to be read and wait for a response

(4) Turn on the bus again

(5) Write address word and wait for response (read command)

(6) Read the address you want to read

(7) Send a response

(8) End the bus

Put the code:

unsigned char read_eeprom(unsigned char add)

{

unsigned char dat;

IIC_Start(); //（1）Start the bus

IIC_SendByte(SlaveAddrW); //（2）Write address word, wait for response (write command)

IIC_WaitAck();

IIC_SendByte(add); //（3）Write the address to be read and wait for response

IIC_WaitAck();

IIC_Start(); //（4）Start the bus again

IIC_SendByte(SlaveAddrR); //（5）Write address word, wait for response (read command)

IIC_WaitAck();

dat = IIC_RecByte(); //（6）Read the address to be read

IIC_Ack(0); //（7）Send a response

IIC_Stop(); //（8）End the bus

return dat;

}

The process of writing eeprom is the same as PCF8591

void write_eeprom(unsigned char add,unsigned char dat)

{

IIC_Start();

IIC_SendByte(SlaveAddrW); //Address word

IIC_WaitAck();

IIC_SendByte(add); //Transmit the address to be written

IIC_WaitAck();

IIC_SendByte(dat); //Number to be written

IIC_WaitAck();

IIC_Stop(); //End

somedelay(10); // appropriate delay

}

Now let's summarize the pitfalls in the I2C official driver:

(1) The delay needs to be changed to 33 nops

(2) After reading the data, the host sends a response of ack(0)