I am using the DS100KR401 on a PCB design and am unable to get the SMBus register values to effect the operation of the device. I know we are communicating with the DS100KR401 via SMbus because I can read the contents of registers. I can write new contents to the register and read it back. According to the documentation, the only thing I need to do to enter SMbus mode is tie the ENSMB pin to VDD through a 1K ohm resistor. I also have the ~RESET pin tied low. I've tried basic stuff like disable channels and enable channels. After writing all 1's to the register I still see a signal out. When I try to change EQ or DEM settings, there is no change to the output waveform (observed on a scope). We also have the eval board for the DS100KR401. We've set up the device the same way that we have it set on the product board and the results are the same. I feel we have something fundamentally not set up correctly (pin ties). Or, after writing a register, is some other function required to make the new register settings active? We are stuck right now. Please provide any help that you can with this issue.
Thanks in advance,
Mike Nycz
