NAND Flash Memory

Flash memory involves specific technology that allows it to retain data even when the supply of power is turned off. NAND is a specific form of flash memory. This type of flash is much faster than NOR flash memory but uses basically the same principles. You will find flash memory in a wide variety of electronic devices from USB sticks to Mp3 players and digital cameras. NOR flash is also used in many portable electronics although NAND flash has many more benefits.

NAND flash was designed with a small cell size. This allows it to work with a very low cost per bit. The differences between NAND and NOR flash memory has become increasingly difficult to decipher. New controller options have made NAND a highly competitive alternative for applications on a wider scale and as the density of this flash memory continues to increase, the cost per bit have decreased. Because of this and the fact that it provides a much faster write/erase performance many memory designers now prefer using NAND over NOR.

The basic characteristics of NOR flash memory include a higher read speed, slower write speed, slow erase speed and a lower density. NOR flash memory is the preferred type for executing such codes as application or boot codes due to its direct random-access interface. There is however a disadvantage to this interface in that additional address lines must be accommodating when upgrading to a memory chip with a higher density.

The basic characteristics of NAND flash memory include a medium read speed, higher write speed, indirect or I/O access, higher erase speed and a much higher density than NOR. NAND flash memory also has internal address, data and command registers and even though this specific interface may seem more confusing and burdensome, it is much easier to upgrade NAND to a device that is higher in density than it is to upgrade NOR flash memory. Because NAND operates on an indirect interface, the external connection to the host will not change when the density of the chip changes. It works much in the same way that a hard disk drive interface works where the different densities use the same cable interface.

Many prefer NAND flash memory over NOR because of the higher density and the higher write, programming and erase speeds at which NAND operates. However, most will agree that when you need to boot out of a flash drive or execute a specific code from a flash drive, NOR flash memory may be a better choice. When choosing a flash memory it is important to keep several things in mind including the differences between a single-level cell flash and a multilevel cell flash. Multilevel cell flash has been used with both NOR and NAND flash memory and is very cost effective for specific applications. It helps to expand the range of performance as well as helping to enable designers to choose the one product that best suits their specific systems.

There are many multilevel cells flash memory drives today that combine NOR, NAND and a number of other memory based components. These are used regularly in the development of specific cell phones and allow specific designers of other products to provide a higher density performance flash memory at a much lower cost and to implement it within a much smaller overall space. Designers for specific products can use NAND to provide a much less expensive approach to memory. This flash memory is now preferred by most new product designers because of this cost effective approach as well as the other benefits that NAND flash memory provide.

This NAND Flash Memory Review is Written/Updated on Oct 22nd, 2010 and filed under Computer Hardware. Both comments and pings are currently closed.

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