Flash (flash or flash memory) first introduced by Intel in 1988 is a non-volatile memory that can be erased and programmed electrically, and its speed is relative to EEPROM. Flash is divided into two categories: Nor Flash and Nand Flash from the chip process.
Nor Flash
Nor Flash is characterized by execution in chip (XIP), application programs can be run directly in the memory Flash, no need to read the code into the system RAM. The transmission efficiency of Nor Flash is very high, and it is very cost-effective in the small capacity of 1~4MB.
Nand Flash
The structure of Nand Flash can provide extremely high cell density, can reach high storage density, and the speed of writing and erasing is very fast; however, its management and control are more complicated.
Non-volatile memory-
Nor Flash Nor Flash can be divided into parallel and serial according to the number of bits of data transmission. Parallel Nor Flash transmits multiple bits of data each time; while serial Nor Flash transmits one bit of data each time . Parallel Nor Flash has a faster transmission speed than serial Nor Flash.
The
main interface of serial Nor Flash has SPI, Dual SPl, Quad SPI mode.
Parallel Nor Flash
main interface has 8-bit, 16-bit, 8-bit/16-bit optional data transmission methods.
Non-volatile memory-Nor Flash features
Features: Nor Flash is a non-volatile memory, generally used for program code storage. The
main push capacity is 256Kb-512Mb.
Serial: MCU with SPI port, less IO port, low cost, small size, low speed High, the application is very wide.
Parallel: MCU needs to have an external bus, fast, no FLASH
inside, etc.Used on high-end platforms such as AMR9, ARM11, A7, A8, A9
Non-volatile memory-Nand Flash features
Features: large capacity, fast writing speed, etc., suitable for storage of big data,
main push capacity 512Mb-8Gb
parallel: MUC with external storage controller, large data volume, fast speed,
used in AMR9, ARM11 , A7, A8, A9 and other high-end MCUs; running WinCE/Linux/Android and other operating systems
Serial: MCU with SPI port, less IO port, low cost, and small size.
Currently only GD (Beijing Zhaoyi) is producing related Products but we do not push the storage of this product line
Flash application
The difference between Nor Flash and Nand Flash
NOR
1. Fast reading speed, slow writing speed
2 Slow erasing speed
3. The number of erasing is about 100,000 times
4. The capacity is small 256Kb-512Mb
5. The unit capacity is high in price, suitable for small capacity programs Storage
6. Not easy to produce bad block
NAND
1. Slow reading speed, fast writing speed
⒉ fast erasing speed (( 1000:1)
3. The number of erasing is about 1 million times
4. Large capacity 512Mb-8Gb
5. Low unit capacity price , Suitable for large-capacity data storage
6. Bad blocks are more likely to occur, and ECC verification is required