SNIU028D February 2016 – September 2020 UCD3138 , UCD3138064 , UCD3138064A , UCD3138128 , UCD3138A , UCD3138A64
New PMBus standards have introduced a quick command read, where the Master send just an address with the last bit set for a read, followed by a stop. This needs to be handled like any other read command, including putting at least one byte into the RXBUF. The STOP from the master will terminate the transmission from the slave, so it will be handled properly. As described above, the PMBus hardware will not ACK the address until something is written to RXBUF.