Flash Memory Cards
Flash memory cards are used to store and transfer data. They are what we know in the consumer market as flash memory sticks, they are utilized by SSDs (solid-state drives), particularly on personal computers, smartphones, and gaming consoles. They make storing and transferring data easier, foolproof, and more convenient, especially since there is no need to use batteries to power up the cards.
These storage devices are small but capable of storing huge amounts of data, including photos, texts, videos, and audios. Their storage capacity is even greater than that of compact discs (CDs). The typical consumer flash memory capacity is from 4GB to 2TB.
Flash memory cards are a type of EEPROM or electronically erasable programmable read-only memory. They have memory chips that are capable of storing information without the need for power. They are ideal for applications that need to carry volumes of data, which is why these devices typically delete content in whole blocks. Data stored in flash chips are kept in cells that have floating gates for protection. Once the cells are cleared of content, new data can be stored.
SD (Secure Digital), xD (xD-Picture Card), CF (CompactFlash), MMC (Multi Media Memory Card), MS (Memory Stick), and SM (SmartMedia Memory Card) are considered flash memory cards.
Flash memory cards are popularly used for USB drives.
There are two logical technologies used in flash memory devices: NAND and NOR. Both are used for mapping data.
- NAND flash has small blocks that are known as pages. These are where data is managed. NAND flash is utilized in digital cameras, solid-state and USB flash drives, TV set-up boxes, and audio and video players. NAN flash operates at high speed, reading and writing data in a sequential manner.
- NOR flash is for achieving high-speed random access, which allows data reading and writing in specified memory locations. It is ideal for operating systems (OS) and BIOS programs.