SNIU028D February 2016 – September 2020 UCD3138 , UCD3138064 , UCD3138064A , UCD3138128 , UCD3138A , UCD3138A64
The best firmware development setup is to never program the checksum into the program flash.
The disadvantage of this approach is that it requires the use of a PMBus interface every time the UCD3138 is reset. The program won’t start on its own, so the start has to be commanded through the PMBus interface.
The second best setup permits auto startup. It is:
PMBus backdoors are convenient, but unreliable. One bug can kill the PMBus function and the backdoor. A simple backdoor at the very beginning of the program is much more reliable.