Differences between NOR and NAND

[eedac]

In many embedded system, flash chips are applied in design. In general, I heard, use NAND for data storage, whereas, NOR for code storage.

I have questiones:

1. why are the NOR more expensive then NAND much?
2. why NOR need addressing bus, but NAND doesn't?
3. what's the MCU interface NAND, or NOR? what are the differences?

 

[leomecma]

Re: Flash: NOR Vs NAND

1) The NOR FLASH is more expensive because of production volume, NAND Flash is more used then the price fall.
3) In MSP430 devices I think this memory is NAND because it has segments of 512 bytes, and you can erase only a complete segment.

INTERFACE DIFFERENCES
NOR flash is very similar to a random access memory device (RAM). Is has enough address pins to map its entire media, allowing for easy access to each and every one of its bytes. NAND devices are interfaced serially via a rather complicated I/O interface, which may vary from one device to another or from vendor to vendor. The same eight pins convey control, address and data information. NAND is typically accessed in bursts of 512 bytes; i.e., 512 bytes can be read and written at a time (similar to hard drives). This makes NOR ideal for running code, while NAND is best used as a data storage device (hard drive/block device replacement).

Samsung has papers about this diferences ....

look this link too:
**broken link removed**

leomecma