Posted on March 27, 2016 at 15:13>The flash cells must be erased before reuse, but you need to move beyond writing a single word, this is just wrong headed. Even if you have to write a byte or small structure, the way this is done is to journal it over a whole sector/page/block. The memory has finite cycles, 100K for the STM32's as I recall.
Flash, using the mentioned block sizes, already consumes most of the die space. Having smaller block sizes would increase area requirements even more. Other vendors (e.g. Microchip) has implemented some Flash with single-byte access (erase/program), calling it ''EEPROM''. Usual size is 0.5 ... 8kByte, for data usage.
Basically, it is the same technology, trimmed for higher data retention and erase/program cycle count, and higher complexity, and higher costs.
> If you need EEPROM or FRAM you will need to add it externally. The size/structure of these memories is not conducive to the same processes as high speed logic, which is why you typically don't see them mixed these days.
E.g. TI does have MCUs with integrated FRAM (some MSP430 variants). Not sure if it'a a homogenous silicon.
If not prohibited by costs, I would suggest serial FRAM (SPI, IIC). Data retention and number of erase/write cycles is practically unlimited, and without additional delay (Flash/EEPROM has erase times in the milliseconds range).
