nrf9160 number of times a 32 bit word can be written before erase

[Mahendra Tailor]

Hi
The nrf9160 product spec 1.2 states that the number of times a 32 bit word can be written is 2.

I have used the nrf52840 a lot and has a similar restriction but on seeking further clarification it turned out that a cell of 128 bits (4 words) had a maximum number of writes of 8.

This had allowed me to write more optimised code as long as I observed that 128 bit cell limitation for the 840.

Can you please confirm that the nrf9160 uses the same flash technology and so that same 128 bit cell and 8 writes will also apply.

Basically in the 840 I was able to write 5 time to first 32 bit in the 128 bit cell, and then only once for the other 3 and that had solved my problem when I had ported the code from nrf52832 which uses a different flash technology.

Look forward to hearing from you.

PS: I had asked a similar question for 840 early on and that question became one with very high views, so I am hoping that similar interest will apply to this question.

[Simon]

I talked to one of the engineers responsible for the flash module in the nRF9160 and asked if the following applies for the nRF9160:

"The real limitation is that you can write up to 8 times to the same address, as long as you don't touch other 32-bit words inside the same 128-bit block. For simplicity we have stated in the product specification that the maximum is 2 writes for a 32-bit word. The limitation should be considered hard as breaking it may result in bits being flipped." (From: https://devzone.nordicsemi.com/f/nordic-q-a/11357/nrf52-flash-programming-writes-in-a-block-between-erase)

I got confirmed that it did.

Best regards,

Simon

[Mahendra Tailor]

This is great news.
I would urge you to update the documentation to state that nrf9160 uses the same flash technology as nrf52840 and so flash related code can be ported as is from an 840 project, but not from a 832 project.

Thank you and you have a great day.