SLAU358Q September 2011 – October 2019
Some FRAM MCUs have the option to protect an address range in main memory. All data from protected memory space is read as 0x3FFF regardless of actual contents. When the protected memory is not locked, then the contents can be read "as is" if the option "Including Unlocked MPU-IPE" is selected. The programmer must have the address range of protected memory to be able to service the MCU correctly. The protected memory range must be specified in the MPU-IPE Space Addresses Group in the Memory Options window (see Figure 2-16). The protected memory space can be erased and reprogrammed when the option "Including Locked or Unlocked MPU-IPE space" is selected. That option can only be selected when the All Memory option is selected. When the memory region is protected and locked using the MPU-IPE features (see MCU family user guide or technical reference manual for details) then all memory is erased first before programming the MCU. The protected and locked MPU-IPE memory range can be erased and reprogrammed only when the JTAG or SBW communication is used. When BSL communication is used, the locked memory cannot be erased or reprogrammed. Through BSL, memory can only be erased and reprogrammed when the locking option is not used.
When a new code file is programmed with contents outside of the protected area, all memory (except protected memory) can be erased, blank checked, programmed, and verified. If the protected memory space is defined incorrectly, a blank check error will result, because 0x3FFF will be read instead of the expected 0xFFFF.