Can a high number of read/write deteriorate the flash itself?

Question

On embedded microcontrollers such as STM32/ESP/ARM in general is there a deterioration problem in case of high I/O on the external flash?

i'm talking about the famous 4Mb/8Mb/16Mb QSPI flash where generally the codes resides as well.

Say that each 30 seconds i'm going to write an int for example and i do that for all the day long, will the flash die sooner or later?

In this case what is the best HW for embedded system that is capable of withstand high IO? What are the workarounds?

Answer 1

Yes, as the commenters have commented, it will fail eventually. Look in the datasheet for a specification typically called "Endurance". Common on-chip NAND flash endurance limits range from 10,000 writes to 100,000 writes, sometimes even higher, but the only numbers that matter are those in your specific part's datasheet. Once you know the endurance, you can come up with a design that predicts a reasonable lifetime based on write size, frequency, possible compression, RAM caching, etc.

Answer 2

Say that each 30 seconds i'm going to write an int for example and i do that >for all the day long, will the flash die sooner or later?

Look up the number of write cycles in the datasheet, and do the math. Let's say your part can endure 1000000 write cycles, then doing a write every 30 seconds will start to wear it out in 30 million seconds. A year is about 31.5 million seconds...

In this case what is the best HW for embedded system that is capable of >withstand high IO?

Some FRAM (Ferroelectric RAM) can support up to 10¹² read/write cycles. It will last for 31689 years even if you are accessing it in every second. Note that reads also count, but that won't be a problem unless your device loses power and must boot up in every second.

What are the workarounds?

Wear leveling, that's what the controllers in SD cards and SSD drives do. But you'd need a disproportionately big flash to do that for a few counters.

Some microcontrollers have a small amount of backup RAM that can be powered with a battery or supercap over a separate V_bat pin. Don't forget to change the battery every few years. For the price of a battery and a socket you'd get an FRAM though.