I'm using the AD5421 with the CRC / PEC mechanism.
When writing data to the AD5421 everything is ok.
But when reading data from the AD5421 the CRC is sometimes invalid.
I'm always sending command "Write to DAC register" to the DAC and I have automatic readback of the fault register enabled.
So my questions are:
1) Does the AD5421 also send correct CRC in automatic fault register readback frames?
2) Shouldn't the AD5421 start driving the SDO line when /SYNC signal gets low? I've seen that it starts driving the signal not before the 5th bit of the first byte!? So for the first few bits the line is floating. For me this indicates that the CRC can't work for this frames!?
Thanks for your help.