I am struggling with the I2C module of XC161CJ to talk with a real-time clock RTC 8564. In my code, I am doing following sequence to send a DeviceID and an address. But it won't work. 1. while( I2C_uwGetStatus() & I2C_BB ); // wait for bus idle 2. I2C_vWriteData(ClkID); // slave address in Write mode 3. I2C_vGenStartCond(); // start condition 4. while( !(I2C_uwGetStatus() & I2C_IRQD) ); // wait for byte sent out 5. while( I2C_uwGetStatus() & I2C_LRB ); // wait for ACK 6. I2C_vWriteData(0x02 ); // seconds' address 7. while( !(I2C_uwGetStatus() & I2C_IRQD) ); // wait for byte sent out 8. while( I2C_uwGetStatus() & I2C_LRB ); // wait for ACK What I saw from the scope is just ClkID has been sent out, and without ACK feedback. My questions are, 1. How to start a transmission? 2. How do I know it's been sent out? 3. How to check the ACK? 4. How to send another byte? Could somebody tell me what is wrong? Or please send me a piece of your code about IIC operation. my email address is: dzh1234@yahoo.com Thanks a lot. David
Thank you, Mr.Shang. Yes, I solved this problem by switching transmit to receive. Well, my new problem are, 1. How can I know if a byte has been sent out to bus? 2. How can I know a byte has been received to the buffer? 3. How can I know a start condition or a stop condition has been done? David Zhang