I am using UCD90160 and UCD9222 with C6678 DSP.
UCD9222 is a digital PWM controller (using it to power CVDD and CVDD1 of C6678) whereas UCD90160 is a power sequencer (used to power sequence C6678).
Both UCD9222 and UCD90160 has PMBus interface. Currently, they are pulled to a header to be connected to a laptop in order to use the Fusion GUI.
I intend to connect the UCD9222 and UCD90160 PMBus interface to the C66 I2C interface. For the PMBus Alert and CNTRL, is it necessary to be routed to the C66? Or will the PMBUs Data and PMBus Clk suffice. I read in the PMBus Specification that the PMBus Alert (which originated from SMBus) is used to notify the host if the device has a fault or warning condition. I also read that there are 2 means available for a PMBus device to notify the host of a warning or fault condition: the SMBALERT# signal and direct communication from the PMBus device to the host (I suppose this refer to PMBus_Data and PMBus_CLK)
I would like to confirm if the 2 lines PMBus_Alert and PMBus_Cntrl are optional and their functions can it be replaced by the PMBus_Data and PMBus_Clk? If can, I will not route the PMBus_Alert and PMBus_Cntrl to the C6678.
I would also like to clarify if I can connect the PMBus of the 2 devices to the C6678 I2C interfaces ( I believe it should be okay, but the programmer programming C6678 needs to write the driver for I2C interface for C6678 to suit PMBus protocol).