Why is erasing of a single block in NAND flash usually much faster than erasing a single block in NOR flash?
For my current understanding: If all cells of the block share the same substrate and if all Wordlines and Bitlines are powered simultaneously, the time should be the same. Maybe, there could be a slight difference because of the fact that NOR cells are usually physically larger than NAND cells. However, when comparing the information in the two documents Link1 (NOR), Link2 (NAND) there are mentioned around 800ms for erasing a 64kB NOR block, while only 2ms for 128kB NAND block. Where does this huge difference in erase speed come from?