What are the main FLASH memory

FLASH is a Memory chip, full name Flash EEPROM Memory, through the program can modify the data, that is usually said "flash". Its storage properties, equivalent to hard disks, are the basis for flash memory to become a storage medium for all kinds of portable digital devices. Flash memory combines the strengths of ROM and RAM and has electronic erasable and programmable performance, and does not lose data due to power failure, and has the characteristics of fast data reading. So what are the general classes related to flash memory?
SPI Nor Flash adopts SPI communication protocol. SPI Nor Flash has the characteristics of NOR technology Flash Memory, that is, programs and data can be stored on the same chip, with independent data bus and address bus, and can be read quickly and randomly. Allows the system to read code directly from Flash for execution; Single-byte or single-word programming can be performed, but single-byte erasure cannot be performed. The erasure must be performed in Sector or on the entire chip. Pre-programming and erasure must be performed on Sector or the entire chip before reprogramming memory.

Parallel Nor Falsh, also known as Parallel Nor Flash, uses the parallel interface communication protocol, has an independent data line and address bus, it also inherits all features of NOR technology Flash Memory. Because of the Parallel interface. Compared with SPI Nor Flash, Parallel Nor Falsh supports larger capacity and faster read and write speed. However, because it occupies too many address lines and data lines, it will occupy a lot of resources in circuit electronic design.

Parallel Nand Flash, also using the Parallel interface communication protocol, Nand Flash in the process of the process is divided into three types: SLC, MLC, TLC. Nand Flash technology The Flash Memory has the following features: Read and program operations are performed on pages, and erase operations are performed on blocks. It has the function of fast programming and fast erasing, and the block erasing time is 2ms, while the block erasing time of NOR technology reaches hundreds of ms. Small chip size, few pins.
Flash memory is the most important storage IC, mainly for NOR Flash and NAND Flash two kinds. Semiconductor memory chips are mainly divided into non-volatile memory IC and volatile memory IC, the most mainstream non-volatile memory IC is Flash memory, and Flash can be divided into NOR Flash and NAND Flash two categories.

NAND Flash is divided into SLC, MLC, TLC and QLC according to the storage principle, and can be divided into 2D and 3D two categories from the structure. Flash technology is mainly divided into SLC, MLC, TLC and QLC four categories, corresponding to different spatial structures, these four types of technology can be further divided into 2D structure and 3D structure two categories.

SLC NAND has the lowest storage capacity per unit, but also the best performance. SLC NAND has only two different voltage states, so it has the most stable performance and longest life. Compared with mainstream NAND Flash, NOR Flash has low capacity density, slow write speed, slow erase speed, and high price.