MT28C256532W18S Micron Semiconductor Products, Inc., MT28C256532W18S Datasheet - Page 5

• Manufacturer Part Number: MT28C256532W18S
• Description: 256Mb Multibank Burst Flash 32Mb/64Mb Async/page Cellularram Combo, 88-Ball Fbga
• Manufacturer: Micron Semiconductor Products, Inc.

General Description
bination Flash and CellularRAM is a high-performance,
high-density, memory solution that can significantly
improve system performance. The Flash architecture
features a multipartition configuration that supports
READ-while-PROGRAM/ERASE operations with no
latency. An 8Mb partition size enables optimal design
flexibility.
density. Both Flash die share a dedicated CE# and OE#
control.
stacked Flash device enables soft protection for blocks,
as read only, by configuring soft protection registers
with dedicated command sequences. For security pur-
poses, two user-programmable 64-bit chip protection
registers are provided for each Flash device.
ERASE functions are fully automated by an on-chip
write state machine (WSM). An on-chip device status
register can be used to monitor the WSM status and
determine the progress of the PROGRAM/ERASE tasks.
(RCR) that defines how the Flash interacts with the
memory bus. For device specifications and additional
documentation concerning Flash and CellularRAM fea-
tures, please refer to the MT28F1284W18 data sheet at
www.micron.com/flash
MT45W4MW16PFA
www.micron.com/cellularram.
CMOS, dynamic random-access memories developed for
low-power portable applications The CellularRAM device
is available in either 32Mb or 64Mb densities.
RAM products have incorporated a transparent self-
refresh mechanism. The hidden refresh requires no
additional support from the system memory controller
and has no significant impact on device read/write per-
formance.
09005aef80bcd58d
MT28C256564W18S_A.fm - Rev. A, Pub 6/03 EN
The MT28C256532W18S/MT28C256564W18S com-
Two Flash devices are stacked to achieve the 256Mb
The MT28C256532W18S/MT28C256564W18S
The embedded WORD PROGRAM and BLOCK
Each Flash device has a read configuration register
The CellularRAM architecture features high-speed
To operate seamlessly on a burst Flash bus, Cellular-
data
and the MT45W2MW16PFA and
sheets
32Mb/64Mb ASYNC/PAGE CellularRAM COMBO
at
http://
5
256Mb MULTIBANK BURST FLASH
trol how refresh is performed on the DRAM array. These
registers are automatically loaded with default settings
during power-up and can be updated any time during
normal operation. Special attention has been focused
on standby current consumption during self-refresh.
sible mechanisms used to minimize standby current.
Partial array refresh (PAR) limits refresh to the portion
of the memory array being used. Temperature com-
pensated refresh (TCR) is used to adjust the refresh
rate according to the ambient temperature. The
refresh rate can be decreased to lower temperatures to
minimize current consumption during standby. Deep
sleep mode halts the refresh operation altogether and
is used when no vital information is stored in the
device. These three refresh mechanisms are adjusted
through the CR.
flash
sheet and
latest MT45W2MW16PFA and MT45W4MW16PFA Cel-
lularRAM data sheet.
Flash Configurations
tecture (16 banks of 8Mb each) to allow concurrent
operations. Any address within a block address range
selects that block for the required READ, PROGRAM, or
ERASE operation.
(8 x 65,536 bits), designated as parameter blocks, and
the remaining part is organized in main blocks of 64K
words each (524,288 bits). The parameter blocks are
addressed either by the low order addresses (bottom
boot) or by the higher order addresses (top boot).
combination of top or bottom boot (e.g., top/top, bot-
tom/bottom, top/bottom, or bottom/top). Please see
Figures 2 and 3 for more information.
The refresh configuration register (CR) is used to con-
CellularRAM products include three system-acces-
Please refer to Micron’s Web site
Each Flash memory implements a multibank archi-
Each Flash memory features eight 8K-word sectors
The two Flash devices can be supplied with any
Micron Technology, Inc., reserves the right to change products or specifications without notice.
for the latest MT28F1284W18 Flash data sheet
http://www.micron.com/cellularram
www.micron.com/
©2003 Micron Technology. Inc.
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