AMD 2004 Annual Report Download - page 11

Table of Contents
Flash Memory Products
Our Spansion Flash memory products encompass a broad spectrum of densities and features and are primarily designed to support code, or mixed code and
data storage applications in the wireless and embedded categories of the Flash memory market. Our products are used in mobile telephones, consumer
electronics, automotive electronics, networking equipment and other applications that require memory to be non-volatile and electrically rewritten. Our Spansion
Flash memory products are based on two technologies today: single bit-per-cell floating gate technology and two bits-per-cell MirrorBit technology.
Floating Gate Technology. Floating gate is the conventional memory cell technology that is utilized by most Flash memory companies today. A memory
cell comprises a transistor having a source, a drain and a control gate. The control gate regulates the current flow between the source and the drain, thereby
defining whether the memory cell stores a “0” bit or a “1” bit by storing a charge in the cell storage medium. The “floating gate” is a conductive storage medium
between the control gate and the source and drain. It is referred to as a floating gate because it is electrically isolated or “floating” from the rest of the cell to
ensure that stored charge does not leak away resulting in memory loss. Our products using floating gate are typically used for code storage and code execution as
well as in applications that take advantage of their ease of in-system re-programmability. In addition, floating gate technology has the ability to operate at very
high read speeds and temperatures, which we believe is optimal for harsh environments such as automotive applications. Spansion Flash memory products using
floating gate technology are available in densities from one megabit to 128 megabits. These products are designed to meet the requirements of a range of Flash
memory market segments, from the low-end, low-density value segment to the high-performance, high-density wireless segment.
MirrorBit Technology. Our Spansion Flash memory products also include devices based on MirrorBit technology, our proprietary technology that stores
two bits of data in a single memory cell thereby doubling the density, or storage capacity, of each memory cell and enabling higher density products. However,
unlike the conductive storage medium used by floating gate technology, MirrorBit technology stores charge in a non-conductive storage medium without a
floating gate. NOR Flash memory products based on MirrorBit technology require fewer wafer fabrication process steps to manufacture and have a simpler cell
architecture compared to similar products based on single-bit-per-cell or multi-level-cell (MLC) floating gate technology. As a result, MirrorBit technology can
contribute to a smaller die size and improved unit production yields. Due to these characteristics, for a given density, NOR Flash memory products based on
MirrorBit technology can be less expensive to manufacture than similar products based on conventional floating gate single-bit-per-cell or MLC technology.
Our Spansion Flash memory products based on MirrorBit technology are available in densities ranging from 16 megabits to 512 megabits. We believe the
lower cost and higher yields of MirrorBit technology enable us to manufacture higher density NOR Flash products at a cost that is not achievable using
competing NOR MLC floating gate technology. We believe our MirrorBit technology will allow us to compete in certain portions of the Flash memory market,
such as data storage, with die sizes that are similar to NAND Flash memory products on the same process geometry and where high densities and low cost-per-bit
are important.
We are developing a new architecture, ORNAND, based on our MirrorBit technology, which we believe will allow us to develop products that combine
some of the best attributes of NOR architecture and NAND architecture. We believe that ORNAND architecture will allow us to offer products with higher
densities in our traditional NOR Flash memory markets, while enabling us to enter and compete in new markets that have traditionally been served by
NAND-based products, such as removable storage. During 2004, we also demonstrated the ability of MirrorBit technology to store four bits-per-cell, which we
refer to as QuadBit, with a working proof-of-concept. If successful, we believe our QuadBit technology would enable us to target the higher density and lower
cost portions of the removable storage category, which is currently served by vendors of NAND-based products.
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Source: ADVANCED MICRO DEVIC, 10-K, March 01, 2005