What Is Flash Memory?

Date First Published: 10th January 2024

Topic: Computer Systems

Subtopic: Computer Hardware

Article Type: Computer Terms & Definitions

Difficulty Level: 5/10

Learn about what flash memory is in this article.

Flash memory is a type of non-volatile memory that can be read from and written to. It is fast to read and write to and can be written to and overwritten like RAM, but is not as fast as RAM. Since it is non-volatile, it retains data regardless of whether a flash memory device is powered on or off.

Flash memory is most commonly used in smartphones, digital cameras, SSDs, flash drives, SD cards, tablets, and printers. However, it is not used for everything as the cost per megabyte of a hard disk is much cheaper and the capacity is much higher.

Note:

Flash memory is also known as a solid-state storage device. This means that there are no moving parts and everything is electronic instead of mechanical.

How Does Flash Memory Store Data?

In flash memory, information is stored in memory cells. These cells have floating-gate transistors that can capture electrons for an extended period of time, but not indefinitely. To store data, a high voltage traps electrons in the floating gate. To wipe data, the charge from the floating gate is released. To read the stored data, the charge on the floating gate is checked.

Types Of Flash Memory

Different types of flash memory include:

• NOR flash memory - Uses no shared components and can connect separate memory cells in parallel, enabling random access to data. It is faster to read than NAND flash, but it takes longer to write new data and erase data. NOR flash is more suitable for consumer and embedded devices for boot purposes.
• NAND flash memory - Has a higher memory capacity than NOR. NAND memory devices are accessed serially, using the same eight pins to transmit data. NAND flash is more suitable for data storage in consumer devices.

Advantages and Disadvantages Of Flash Memory

• It is durable. Flash memory has no moving parts and relies on electrochemical processes.
• Flash memory consumes less power and produces less heat than hard disks, making it more suitable for devices that run off battery power.
• Flash memory has fast read/write speeds, allowing data to be stored and retrieved faster.

• It is more expensive than hard disks. This gives a limited capacity for the same price and leads to flash memory devices struggling to reach capacities as high as hard disk drives.
• Lifetime is limited. Flash memory can only take a limited number of write/erase cycles before it eventually wears out.

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