MSP430F2272 Flash

The collected information is listed below during flash of MSP430 development.

MSP430F2272: 32KB + 256B Flash Memory, 1KB RAM

The minimum VCC voltage during a flash write or erase operation is 2.2 V. If VCC falls below 2.2 V during write or erase, the result of the write or erase is unpredictable.

MSP430 flash memory is partitioned into segments. Single bits, bytes, or words can be written to flash memory, but the segment is the smallest size of flash memory that can be erased.

The flash memory is partitioned into main and information memory sections. Flash memory has n segments of main memory and four segments of information memory (A to D) of 64 bytes each. Each segment in main memory is 512 bytes in size.

Segment A contains calibration data. After reset, segment A is protected against programming and erasing. It can be unlocked, but care should be taken not to erase this segment if the device-specific calibration data is required.

The flash read operation is identically to ROM read operation. In read mode, the flash memory is not being erased or written, the flash timing generator and voltage generator are off.

Reading from or writing to flash memory while it is being programmed or erased is prohibited. If CPU execution is required during the write or erase, the code to be executed must be in RAM. Any flash update can be initiated from within flash memory or RAM. What’s initiated from RAM? As MSP430 flash memory is in-system programmable (ISP), the specified program which copy some program to RAM and run start the position of RAM or BSL.

The flash timing generator operating frequency, fFTG, must be in the range from approximately 257 kHz to approximately 476 kHz.The erase cycle timing is not dependent on the amount of flash memory present on a device. The segment erase time is about 20ms in 257kHz worst case. Also, other operations cannot be executed as the erase operation is initialed from Flash code.

Erasing needed before flash write. Flash erase sets all bits to 1, so the flash write can either leave the bit alone or switch it to 0. If erase is not performed in advance, a flash write of 1 over a bit that is currently 0 has no effect. You can only do without erase, if the previous content can be reprogrammed to the new value.