Flash and Memory Organization:

The Flash memory in the MSP430 is usually divided into two sections, the main flash, and the Information flash. Main Flash - Represents the bulk of the MSP430’s flash and is used for program code and constant data. Itself divided into several flash banks, with each bank further divided into segments. When a microcontroller is denoted to have ”32kB” of Flash, it is referring to the Main flash:

Information Flash - Several extra segments of flash separate from the Main flash. These are primarily intended for information such as calibration constants but are much smaller than the main banks. The location and amount of each of these sections depend on the specific MSP430 you’re using, and the details are contained in the Memory Map included in the datasheet of the particular MSP430 you’re using. Here is an example of the memory organization of several MSP430 devices, taken from their datasheets. Only Flash sections are included. This information was taken directly from the datasheet of the devices. Please note that some details such as the breakdown of the flash segments were obtained from the linker file since the datasheet lacked these specifics. The use of the linker will be discussed later.

We can see that for the FG4618 device, we have a total main flash size of 01FFFFh - 003100h = 1CEFFh = 118527 bytes

This calculation is easily done using the Windows Calculator in hex mode (the h after each number denotes it is in hex). After the subtraction, convert 1CEFF to decimal.