28F640L18, 28F128L18, 28F256L18
2.0Device Description
This section provides an overview of the features and capabilities of the 1.8 Volt Intel StrataFlash®
wireless memory (L18) device.
2.1
Product Overview
The L18 flash memory device provides read-while-write and read-while-erase capability with
density upgrades through 256-Mbit. This family of devices provides high performance at low
voltage on a 16-bit data bus. Individually erasable memory blocks are sized for optimum code and
data storage.
Each device density contains one parameter partition and several main partitions. The flash
memory array is grouped into multiple 8-Mbit partitions. By dividing the flash memory into
partitions,program or erase operations can take place at the same time as read operations.
Although each partition has write,erase and burst read capabilities,simultaneous operation is
limited to write or erase in one partition while other partitions are in read mode. The L18 flash
memory device allows burst reads that cross partition boundaries. User application code is
responsible for ensuring that burst reads don’t cross into a partition that is programming or erasing.
Upon initial power up or return from reset,the device defaults to asynchronous page-mode read.
Configuring the Read Configuration Register enables synchronous burst-mode reads. In
synchronous burst mode,output data is synchronized with a user-supplied clock signal. A WAIT
signal provides easy CPU-to-flash memory synchronization.
In addition to the enhanced architecture and interface,the L18 flash memory device incorporates
technology that enables fast factory program and erase operations. Designed for low-voltage
systems,the L18 flash memory device supports read operations with V CC at 1.8 volt,and erase and
program operations with VPP at 1.8 V or 9.0 V. Buffered Enhanced Factory Programming
(Buffered EFP) provides the fastest flash array programming performance with VPP at 9.0 volt,
which increases factory throughput. With VPP at 1.8 V,VCC and VPP can be tied together for a
simple,ultra low power design. In addition to voltage flexibility,a dedicated V PP connection
provides complete data protection when VPP is less than VPPLK
.
A Command User Interface (CUI) is the interface between the system processor and all internal
operations of the L18 flash memory device. An internal Write State Machine (WSM) automatically
executes the algorithms and timings necessary for block erase and program. A Status Register
indicates erase or program completion and any errors that may have occurred.
An industry-standard command sequence invokes program and erase automation. Each erase
operation erases one block. The Erase Suspend feature allows system software to pause an erase
cycle to read or program data in another block. Program Suspend allows system software to pause
programming to read other locations. Data is programmed in word increments (x16).
The L18 flash memory device offers power savings through Automatic Power Savings (APS)
mode and standby mode. The device automatically enters APS following read-cycle completion.
Standby is initiated when the system deselects the device by deasserting CE# or by asserting RST#.
Combined,these features can significantly reduce power consumption.
The L18 flash memory device’s protection register allows unique flash device identification that
can be used to increase system security. Also,the individual Block Lock feature provides zero-
latency block locking and unlocking.
Datasheet
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