I am investigating using an MSP430FR type device with a small package at very low temperatures. The FRAM is of particular interest. I found that the MSP430FR5728 will continue running when it is submerged in LN, -196C, but then fails to run after powering down and back up again. The programmer gives me the error "Error connecting to the target: Device configuration data inconsistent. Please discontinue using/replace target device". From the error, it seems that maybe the configuration is somehow corrupted? I have tested another MSP430 non FRAM device at these temperatures without any apparent issues.
I understand that the parts are not rated for these temperatures.