Hi expert,
Lately I read AN-2173"I2C Communication Over FPD-Link III with Bidirectional Control Channel" and have some questions.
As you can see below pic, I think it intends to convey the difference between host I2C and remote I2C but I don't really get it. From my understanding, remote I2C should be slower and the the ACK signal follow previous byte closely. I think we should exchange "HOST I2C" and "REMOTE I2C". What do you think？
BR，
Elec Cheng
Hi Elec,
The App Note diagram is showing remote I2C transactions rather than local I2C. The local transaction like you mentioned has the ACK following closely to the previous byte and does not require clock stretching, see figure below.
However, when communicating with a remote peripheral, the slave proxy will forward any byte transactions sent by the Master controller to the target device and slave clock stretching occurs. Figure 5 is showing the timing relationship of the SCL clock and SDA data signals as each byte transferred to the I2C slave must be acknowledged separately. The clock stretching will be done for each byte sent by the host controller.
Best,
Shu
