Datasheet
COMMITTED T O MEMORY
kingston.com/ash
Die-Stacking and Multi-Level Cell/Multi-Bit Cell Flash technologies
In order to economically increase the amount of bit-storage that a Flash memory chip can
accommodate, manufacturers often utilize die-stacking and multi-level cell or multi-bit cell
technologies. These technologies result in a Flash memory chip having the capability to
store more data in a single chip.
5.1 DIE-STACKING
Many semiconductor manufacturers use a “die-stacking” technique to double a Flash
memory chip’s capacity. After the semiconductor wafer fabrication process, they cut out the
Flash memory silicon “die” and then attach or stack two separate dies together.
For example, when a semiconductor manufacturer stacks two 1 gigabit dies together, they
form a single 2 gigabit Flash memory chip.
Die-stacking allows for cost-reduced chip alternatives to the larger-capacity, single-die chips
(called “monolithic” chips). Stacking two 8-gigabit chips together, for example, typically
costs far less than buying a low-volume monolithic 16-gigabit chip. The 16-gigabit chip can
then be used to build a 2-GB Flash card (single chip card), or a 4-GB Flash card (two chips
on one card).
Die-stacking is similar to the DRAM chip-stacking technology that Kingston utilizes to
produce high-end server modules. As a result, Kingston’s die-stacked Flash cards are reliable
and deliver high performance.
5.2 MULTI-LEVEL CELL (MLC) FLASH TECHNOLOGIES
NAND and NOR Flash memory chips store one (1) bit value (a “0” or a “1”) in each cell. In
multi-level Flash technologies, two (2) or more values are stored into each cell.
Intel Corporation has introduced NOR StrataFlash
™
; AMD has introduced NOR MirrorBit
™
Flash. Other semiconductor manufacturers also manufacture their own multi-level cell
technologies.
NAND MLC Flash technologies were introduced in late 2002, and Kingston has incorporated
MLC Flash memory into its line of standard Flash cards and DataTraveler (DTI/XXX) USB
Flash drives.
5.3 MULTI-BIT CELL (MBC) FLASH TECHNOLOGY
Multi-bit technology is a competing technology to Multi-Level Cell (MLC), and accomplishes
the same goal by storing 2 bits per cell (or 4 values per cell). MBC technology is presently
used in Inneon’s TwinFlash
™
memory.
CompactFlash cards
were the rst small
form factor Flash
memory cards.
5.0
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