Sometimes designs will have a series resistor up close to the slave device. It is used as a debug point and to be able to disconnect the slave from the system I2C bus. you do not need this
Looking at the waves, it looks like the master is driving the signals high. I would expect to see a RC rise time on the rising edges. Please make sure the master is SDA pin is tri-state during the ACK cycle.
Normally I2C interfaces will set the output data bit to zero and toggle the direction register for the pin. So
for direction = in, the output will go high
for direction = out, the output will go low
for pin input set direction = in.
during the ACK period the master must be set as an input.
Hi GuenterL,
I found 1 problem with my layout.
I don't use PAD under ADV7513 in my layout.
That's issue with my I2C signal ??
PAD
Ground. The ground return for all circuitry on-chip. It is recommended that the ADV7513 be assembled on a single, solid ground plane with careful attention given to ground current paths.
Best regards.
Alex
1) Do you have a series resistor in SDA?
2) If so what are the values of the pull up and series resistor?
2) Which side of the series resistor is the scope connected to? My guess would be the side closest to the bus master
The location of the step is the ACK back from the 7513.