The growth in the market for portable computing devices has led to
high demand for small size storage. Flash memory is ideal for
this
Contrary to what its name may imply, Flash memory is here to
stay. Since its inception almost 15 years ago, Flash memory has
evolved into a versatile and practical storage solution. Recently,
new applications and rapidly increasing demand for Flash have
brought this adaptable, yet advanced technology to the front door
of many business applications.
Flash memory is a solid-state, non-volatile, rewritable memory that
works like RAM and is hard-disk drive combined. Flash memory stores
bits of electronic data in memory cells, just like DRAM and SRAM,
but Flash also works like a hard-disk drive because when the power
is turned off, the data stays in memory. Flash memory is becoming
increasingly popular for portable computing and communications
applications. Here are a few reasons why: Nonvolatile storage -
retains data even with the power off (much like a disk drive) Low
voltage - consumes very little power and saves battery life
Durability - able to withstand severe shock or vibration without
losing data Compact size - suitable for a broad range of portable
electronics speed - extremely fast access timeFlash memory and RAM
look very much the same. Both can come in the form of discrete
chips, modules, or memory cards. They store information in the same
way, but Flash memory doesn't need to be constantly refreshed like
DRAM, and it doesn't need constant power to retain data like SRAM.
Flash memory is non-volatile, which means that it retains its data
even when the power is turned off. The question is sometimes
raised: "If Flash works like RAM but it doesn't need power to
retain data, why not use Flash to replace main memory in
computers?"There are several reasons why this can't be done. First
of all, the memory cells in a Flash chip have a limited lifespan of
100,000 write cycles. Also, because of its design, Flash memory
must be erased in blocks of data rather than single bytes like RAM.
(That's like having to erase the entire word every time you press
the "delete" key, instead of erasing a single letter.) Beyond that,
Flash memory is too expensive to compete with RAM for main memory.
Nevertheless, while it bears some similarity to RAM, Flash memory
has been carving out its own independent markets, with little
direct competition to RAM. Some examples include: Discrete Flash
chips used in desktop PCs to store system configuration information
Flash modules used in networking equipment to store microcode and
instructions Flash memory cards used in portable computers and
palmtops for mass storageMagnetic disk drives have moving parts and
thus a lower tolerance for shock, vibration, extreme temperatures,
or harsh environments. Electronic "Flash drives" have no moving
parts to draw excess current, so they consume less energy yet are
smaller and faster than hard-disk drives. Flash memory can also
withstand shocks up to 2000G's without losing data. That's roughly
equivalent to a 10ft drop onto concrete. Also, with no physical
surface like on a standard hard drive platter to grab data from,
data access time is significantly decreased. Again, the question is
sometimes raised, "If Flash is faster and smaller than a hard-disk
drive, why not use Flash memory to replace all hard drives?". The
reason is that in practical applications, Flash memory and
hard-disk drives serve different purposes. For example, typical
desktop PCs need gigabytes of storage space (far beyond the present
capacity of Flash memory - about 100Mb). Also, desktops don't have
power constraints because they're plugged into A/C outlets, and
durability isn't an issue because they're stationary. In this case,
there's no need for the features that Flash has to offer. Plus, as
with RAM, Flash cannot compete with hard disks in price. However, a
Flash drive would be more suitable than a hard-disk drive in
situations where size, power consumption, and ruggedness are
important factors, and where capacity needs are smaller. Some
examples would include handheld computer games, digital cameras,
palmtop computers in manufacturing environments, or notebook
computers in medical, insurance claims, and military/government
field situations.Because of its ability to withstand tremendous
shock without losing data, its ability to store information without
constant power, and its low voltage requirements, Flash memory is a
suitable replacement for portable hard drives in rugged situations,
yet its range of applications is also broader. Some other
applications for Flash memory include: digital cameras, cell
phones, pagers and audio recorders, scanners - to store images and
voice data networking devices; to store the microcode and
instructions needed for transferring data printers and print
servers; to hold fonts or frequently-used graphics desktops; and to
replace ROM BIOS chips (the BIOS configures your computer every
time you turn it on).One ideal application for Flash memory would
be in a digital camera, like the KODAK Digital Science DC40 or DC50
Zoom camera. In this camera, Kingston's 20Mb Type II Flash
(DP-ATA/20) card would function as an electronic "roll" of digital
film. In fact, depending on data compression, an average of 6 to 15
pictures per Mb could be stored in this Flash card. After taking
pictures in the field (e.g. police, insurance adjusters,
architects), the digital images could be loaded directly into any
notebook or desktop. Another instance might be in a truck that uses
an on-board computer. Every time the truck hits a pothole in the
road, the system could crash, but not with Flash memory.While Flash
memory is in no position to compete with RAM or disk-drives in
functionality, price, and capacity, it brings distinct advantages
and opportunities for various business applications. With an
increasing number of applications, Flash memory growth is
expanding. At present, Flash memory is one of the fastest growing
segments of the semiconductor industry. As prices drop and
capacities increase, Flash memory will probably continue to grow in
the PC Card market with the greatest growth in digital recording
and wireless communications.
Compiled by Ajith Ram(c)
1999, Kingston Technology Company