Contents
What is NOR type flash memory?
NOR flash memory is one of two types of non-volatile storage technologies. Non-volatile memory doesn’t require power to retain data. NOR and NAND use different logic gates — the fundamental building block of digital circuits — in each memory cell to map data.
What is the difference between NOR and NAND flash memory?
In NOR Flash, one end of each memory cell is connected to the source line and the other end directly to a bit line resembling a NOR Gate. NAND Flash, in contrast, has a much smaller cell size and much higher write and erase speeds compared to NOR Flash.
Is flash memory RAM or ROM?
It’s neither RAM or ROM. Flash memory is EPROM (Electrically Programmable Read-Only Memory).
Can a flash write set a bit to 0?
Flash erase sets all bits to 1, so the flash write can either leave the bit alone or switch it to 0. If erase is not performed in advance, a flash write of 1 over a bit that is currently 0 has no effect. RE: Flash Write: Realy need erase before? Friday, March 12, 2010 9:28 AM ( permalink )
Can a flash write of 1 be done without erase?
Flash erase sets all bits to 1, so the flash write can either leave the bit alone or switch it to 0. If erase is not performed in advance, a flash write of 1 over a bit that is currently 0 has no effect. You can only do without erase, if the previous content can be reprogrammed to the new value.
Is the entire page erased before writing just a few bytes?
Partial-page programming, non-sequential pages programming within the block, excessive read per block without erase as well as non-equal number of read operation within a single block increase number of the read disturb errors.” — Michal Jedrak. “NAND Flash memory in embedded systems”.
How big of a area does flash memory need to be erased?
I’m writing drivers for a SST25VF064C flash memory chip. It communicates via SPI. Like all flash memory (that I know of), it needs to be erased (all bits = 1) before it can be written (bits = 0). For this chip, the smallest area that can be erased is 4kB.