#STM32F446RE NUCLEO BOARD ONLINE HOW TO#
#STM32F446RE NUCLEO BOARD ONLINE FREE#

The number of supported write cycles for your part should be documented in the datasheet, you exceed that for the lifetime of the product you built with this device, it can forget what you wrote.

#STM32F446RE NUCLEO BOARD ONLINE HOW TO#

Lots of solutions and opinions on how to not wear out your flash, and sadly some of the flash hardware has logic that does write leveling, which if both software and hardware are trying to spread things out to reduce the wear on the flash they can work against each other and do more harm than good. Quite simple to implement, but still better than wearing out flash. Ideally you want support on your board to detect the power going down, at the same time have enough bulk capacitance or a battery or both to keep the board/device alive long enough for the worst case amount of time it needs to save the non-volatile information (ideally confirming first that the values have changed otherwise dont burn an erase cycle).

#STM32F446RE NUCLEO BOARD ONLINE FREE#

And the documentation tells you how to do this.Īnd that is all great but some free advice is you can wear out your flash if you do this wrong, in hours or part can be trashed. These days it is common (although there are many exceptions) to have the ability in application to write to an on chip non-volatile memory (eeprom/flash). In any case you have to look at the documentation for your chip and or chip family. sometimes you have both flash and eeprom the eeprom for the kind of thing you may be asking for here, and sometimes for reverse compatibility reasons they have an eeprom legacy interface but it is really using the main flash for storage. So static ram is static in the sense that we only have to tell it once and it remembers, dynamic ram is dynamic in the sense that we tell the dram system what that bit is and as a system we have to keep reminding it, this is done by reading the bit then reprogramming/charging that bit at a certain frequency.ĭRAM is cheap, can pack four times the number of bits into the same number of transistors, SRAM is fast dont have the complicated overhead nor refresh cycles getting in the way, it is just gates so can run as fast as other gates as fast as the gates doing other things (processing instructions).Ī microcontroller will have some form of non-volatile storage in it ROM, PROM, EEPROM or flash (of which there are now various flavors). DRAM though uses one transistor and to some extent relies heavily on the capacitance in that transistor, kind of like a lame rechargable battery, you want it to remember a 1 you have to charge it up and it discharges quickly (as in milliseconds) so you have to constantly remind it it is a one or a zero (refresh). Static uses four transistors lets say, two gates with feedback in a classic flip flop implementation, you write the bit high or low and so long as the power doesnt turn off it stays that value it doesnt forget (so long as the power stays on). Instead in both cases they have to do with memory that remains powered, they are both volatile memories. The S in SRAM is for Static sure which the term implies it might survive esp when you learn for DRAM the D means dynamic, and perfectly fine to assume one survives a power cycle and the other does not but unfortunately that is not what they refer to. volaitle means it cannot non-volatile means it can. Volatile in this sense means it can or cannot survive a power cycle.

And flash is a newer technology electrically eraseable and programmable rom or non-volatile storage. ROM implementations are not technically read only PROM is programmable rom which means writeable, so that kinda breaks down the term EPROM electrically programmable, EEPROM is electrically eraseable and programmable. The convention is that ROM is non-volatile and RAM is volatile which are the relevant terms here. Now RAM by that definition can be safe to use for things like a ROM (Read Only Memory) as the Random part has to do with addressing, can I address any random address I want or can I only read this thing using linear one address after the other per some rules. SRAM means Static RAM, RAM means Random Access Memory. Would do instead of normal RAM? RAM=lose value when no power, So adding a major section to this answer, your comment is critical here:īut Is the value stored even after power down? Isn't that what SRAM EDIT, your question COMPLETELY changes the answer as you are not interested in SRAM writing at all but flash/eeprom.

Stm32f446re nucleo board online