Block write BLKWRT mode is used to program the Flash in block sizes
of 64-bytes. Selecting this option accelerates the time to program
a byte or word of Flash. This feature can be used in a system only
if the code that does the BLKWRT is executed out of the RAM. The
data to be written to the Flash should also be in the RAM area.
During the BLKWRT phase, the user code must never access the Flash
memory module for any reason, otherwise an access violation occurs
and the ACCVIFG is set. Refer to the Flash Memory Controller chapter
in the MSP430xxxx User`s Guide for details.