7.4.2.1 Selecting the Dual Boot Mode

The Dual Partition Program Memory mode is selected by programming the BTMODE [1:0] bits in the FBOOT Configuration Word, which is a part of the UCB configuration area. When a device is first programmed via In-Circuit Serial Programming™ (ICSP™), the programmer should program FBOOT to correctly set the device Flash Partition mode. Note that it is not possible to reprogram FBOOT at run time using Run-Time Self-Programming (RTSP). The FBOOT bits must be configured in ICSP mode by a programmer.

The Operating mode is always established after (any) Reset and is immediately followed by the Flash Fuse read/load sequence. Four modes of operations are possible depending on the FBOOT value.