SNIU028D February 2016 – September 2020 UCD3138 , UCD3138064 , UCD3138064A , UCD3138128 , UCD3138A , UCD3138A64
A total of 4 PMBus command bytes have been assigned for read functionality in the UCD3138 Boot ROM. 3 of these messages utilize a read format, in which the PMBus Master provides an address and command byte to the UCD3138 and expects read data returned by the slave. These commands make it possible to read from any valid memory location. They can be used to read from peripheral registers as well as from memories.