During the whole life of Nand Flash, Is read a safe operation?

2
votes

On today's interview, i have been asked a interesting question

"During the whole life of Nand Flash, Is read a safe operation?"

We all know that erase or write will cause bad block. But is read operation safe? for example, if i put some data into nand flash, and never change it after.I just read it over and over again, will there be some problems?Also i'm told that this have no relation to ECC

1
filesystemsembeddedflash-memory
It is highly dependant on the technology. It is best to use a file system that assumes they will wear. Everything eventually wears out. MLC flash is typically read-disturb, but SLC doesn't have this specific problem. Every floating gate will eventually discharge. Many parts guarantee higher reliability for the first/boot blocks. It IS related to ECC; if a read bit flips, the ECC catches it. – artless noise

1 Answers

4
votes

No, read operations can cause read disturb problems. Search for "nand flash read disturb" on Google for example, it will give plenty of articles on the matter, for example this at Micron, or this at SanDisk.