NAND and NOR flash Memory

These are the two types of external interface non-volatile memories(retains the memory even when power is not supplied) ,used for storing the boot files,data storage for processors.

It stores the data as the building block of the logic gates which is the digital circuit mapping the data.

NAND Flash is of higher memory size than that of NOR Flash. Theses are used in the embedded system devices such as the Smart phones,wearable devices etc., because of their low power consumption over SRAM,DRAM etc.,

Basically NOR Flash is used for storing the Boot files and NAND is used for data storage. NOR Flash can read faster while NAND Flash writes fast. NOR flash provides XIP(Execute-in-place) feature in which the application runs directly rather than transferring it to the system RAM.

NOR flash can be accessed via SRAM interface in a random way as it is memory mapped while NAND flash can be serially accessed through I/O interface like eMMC, SPI etc., in a sequential manner.

As the NAND flash memory size is larger it requires separate flash management controller units in some application. NOR flash is expensive than NAND flash but both the types of flash memory serves at its the best when implemented based on the specific application requirement.