The origin of the name Flash

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The origin of the name Flash [Copy link]

Origin of the name Flash The erasing operation of Flash is based on blocks. In contrast, many other storage devices use bits as the minimum read/write unit. Flash erases the entire block at once: after sending an erase command, a block (common block size is 128KB/256KB) is erased to 1 at once, that is, all the contents inside are 0xFF. Since it is erased at once, the erasing time is relatively short, which can be described as a flash, so it is called Flash Memory. Some Chinese translations are (fast) flash memory. [Speciality of Flash relative to ordinary devices] 1. As mentioned above, the minimum operation unit of Flash is somewhat special.

General devices, such as hard disks/memory, read and write in bits. Reading a bit value and writing a value to the corresponding address bit can be done bit by bit.

However, due to the physical characteristics of Flash, the internally stored data can only change from 1 to 0. This can be understood from the internal implementation mechanism mentioned above. It is only convenient for unified charging, and it is not convenient for individual storage units to discharge. That is why it can only change from 1 to 0, that is, release the charge.

So, to summarize the particularity of Flash is as follows:

	Ordinary devices (hard disk/memory, etc.)	Flash
The names of read/write	Read/write	Read/Program (Program) ①
The smallest unit of read/write	Bit/bit	Page/page
The smallest unit of erase operation	Bit/bit	Block/block②
The meaning of erase operation	Delete data/write all 0	Erase the entire block to all 1, that is, the data inside is 0xFF③
For write operation	Just write directly	Before writing data, erase it first, then write

Table 2. The special features of Flash compared with ordinary devices

Note:

①The reason why the write operation is called programming is that Flash is the successor of the previous EPROM and EEPROM. The previous EEPROM (Electrically Erasable Programmable Read-Only Memory) was called programming when data was written into it. The reason for this is that the writing of data requires electricity to erase/write, which is called programming.

②For Nand Flash, whose common page size is 2K/4K, the block size is 128KB/256KB/512KB, etc. For Nor Flash, the common block size is 64K/32K, etc.

③Before writing data, it must be erased first, and the internal data will become 0xFF, and then data can be written, that is, the corresponding bit is changed from 1 to 0. Shenzhen Leilong Development Co., Ltd. has been engaged in NANDFLASH industry for more than 10 years. Currently, it is the agent of ATO Solution small capacity SLC NAND, SPI NAND, MCP, etc. For more information, please contact 28522668; Tel: 13691982107

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