SNIU028D February 2016 – September 2020 UCD3138 , UCD3138064 , UCD3138064A , UCD3138128 , UCD3138A , UCD3138A64
The firmware program in UCD3138 EVM tools run in User mode. This is an additional protection against unforeseen events in the program. Among other things, writing to any DEC register in user mode will cause a processor reset. So before doing any flash write, it is necessary to switch to supervisor mode. This is normally done by issuing a software interrupt. Examples can be found in the reference source code for UCD3138 EVMs.