In a data logger application, the program code size required to measure and collect the data can be comparably small with respect to the amount of memory to store the data. Assuming the use of external memory is not an option and the data would be stored in the RAM of a "traditional" flash-based microcontroller, one would have to purchase a device that has excessive program memory compared to what the application needs. With a FRAM-based microcontroller, the available memory can be partitioned to the needs of the application and, therefore, a much larger portion can be made available for data to meet the application requirements.

Figure 2-2 Unified Memory

The concept behind this is called unified memory. Universal memory allows flexible partitioning of the memory for code and data.The same type of memory can be used for both data and program storage that are "traditionally" kept in separate memories—RAM for data and flash or ROM for program storage.

To support the "unified memory" concept, a Memory Protection Unit (MPU) is implemented in the FRAM-based MSP430 devices from Texas Instruments. The MPU allows protection for parts of the memory that are used for program storage from being accidentally overwritten.