Is there an application note or specification that defines the term flash memory endurance and flash memory retention?
What failure modes can be expected when these specs are exceeded?
Is there an application note or specification that defines the term flash memory endurance and flash memory retention?
What failure modes can be expected when these specs are exceeded?
The product specification gives the answers for your questions:
Endurance: 20000 Erase/Write cycles
Retention: 10 years at 40°C
I saw those lines in the specification, but I want to understand what definition Nordic is using for these terms.
What is the expected failure modes if these specifications are exceeded?
The type of failure is not specified when 20.000 erase cycles are exceeded. The flash may last longer but 20.000 cycles is guaranteed endurance. I suspect though that the failure will be that flash pages can not be properly erased or written anymore which will cause flash data to be incorrect.