Mandar Joshi
Member level 2
I have interfaced MCP7940M with AVR. I know working of I2C where in case of RTC write we use following sequence:
1. Start
2. Slave address+Write bit
3. Register address
4. Register data
5. Stop
And of course after each byte there is ACK or NACK
But actual confusion is in RTC read
Definitely first two steps will be as it is only there will be slave address+read bit
After this two steps if I directly start reading data then do I need to mention address of register to be read every time, if not then in what sequence we receive the data?
Also one more question, in many codes I have seen REPEATED START while reading data what is that for?
One may think these are silly question but I am not getting these points by simply reading other threads. So it would be helpful if someone explains me this.
1. Start
2. Slave address+Write bit
3. Register address
4. Register data
5. Stop
And of course after each byte there is ACK or NACK
But actual confusion is in RTC read
Definitely first two steps will be as it is only there will be slave address+read bit
After this two steps if I directly start reading data then do I need to mention address of register to be read every time, if not then in what sequence we receive the data?
Also one more question, in many codes I have seen REPEATED START while reading data what is that for?
One may think these are silly question but I am not getting these points by simply reading other threads. So it would be helpful if someone explains me this.