Norflash and nandflash cannot be clearly understood

Norflash and nandflash cannot be clearly understood
Differences between nor flash and nand flash

I have been studying embedded systems for a while. I was confused when I first came into contact with nor and nand. I had to write a blog to remember clearly.

First, they are all storage devices, collectively referred to as flash memory. The reason for their difference must be the hardware difference. // It seems that men and women have different hardware before developing physiological differences

Different underlying causes of performance and usage (hardware): the logical device that makes up the storage unit. nor and non-gate, and nand adopt or non-gate. In fact, the so-called nor and nand are based on different manufacturing technologies. Literally, the nor is the non-gate, and the nand is the or non-gate, which is the smallest logical unit when the IC is made. It is like we say that the cmos device is built by a pmos and a nmos cmos as the basic unit.

Performance differences between nor and nand:

Nor reading speed is fast. nand writing speed is fast and can be erased. nand is 100 w, nor is 10 w.

Differences between nor and nand interfaces:

Nor has an sram interface and enough pin address, so it is easy to have every byte inside it. (So programs can be directly run in nor) nand uses a complex io port, similar to hard disk.

Differences between nor and nand usage:

Nor is used to store the system or firmware. Because the write speed is slow, but the read speed is fast, and each byte inside can be directly addressed, the program can run and debug in nor. The usage of nand is a bit similar to that of hard disks. Nowadays, many USB flash drives use nand. If not, check whether your USB flash drive is used. Due to the fast writing speed of nand and the fast writing mode, it is used to store enlarged data or configuration files. A long time ago, embedded flash systems used ram, but now they have been replaced by nand. Previously, pc hard disks used ram, sram, dram, and so on. Now they also used nand.