Stec UFD 4GB SLUFD4GU2TUI User Manual
Product codes
SLUFD4GU2TUI
SLUFDxxxU2TU(I) Data Sheet
STEC™ Industrial Grade USB Flash Drive
61000-07007-107, September 2012
8
3.2.3 Error Correction/Detection
The USB 2.0 Interface Controller implements an advanced Error Correction scheme, based on the BCH
error correct algorithm. The ECC engine can correct up to 16 bits per 1 KByte. To ensure the fastest
performance, correction is done on-the-fly, in hardware only.
error correct algorithm. The ECC engine can correct up to 16 bits per 1 KByte. To ensure the fastest
performance, correction is done on-the-fly, in hardware only.
Each time the host application writes a sector of 512 bytes to the industrial grade USB flash drive, a
unique ECC signature is created by the ECC engine and written together with the data to the flash. When
the data is read back by the host, the ECC engine creates again the unique ECC signature. It will then
compare the original written signature with the newly created signature, and sets an error flag if the two
signatures are not the same. Correction of the data is done on-the-fly when the error flag is set, and the
data presented to the host will be the same as the original written data an Uncorrectable Bit Error Rate
(UBER) of less than 1 in 10
unique ECC signature is created by the ECC engine and written together with the data to the flash. When
the data is read back by the host, the ECC engine creates again the unique ECC signature. It will then
compare the original written signature with the newly created signature, and sets an error flag if the two
signatures are not the same. Correction of the data is done on-the-fly when the error flag is set, and the
data presented to the host will be the same as the original written data an Uncorrectable Bit Error Rate
(UBER) of less than 1 in 10
14
bits, read.
3.3
OS Support
The industrial grade USB flash drive is recognized as a removable drive and supports the following
Operating Systems, as listed in Table 5.
Operating Systems, as listed in Table 5.
Table 5: Supported Operating Systems
Operating System
Version
Windows 98/2000/XP/Vista/Windows 7
Windows XP Embedded
Service Pack 2007
Windows CE
4.2 and 5.0
Windows for POS (WEPOS)
VxWorks
6.1 and up
Linux
Kernel 2.4 and up
Note: Windows 98 requires driver.
3.3.1 Using USB Flash Drive with XP Embedded
When using the industrial grade USB flash drive with Windows XP Embedded, it is recommended that the
Enhanced Write Filter (EWF) feature is implemented. The EWF intercepts calls at the sector level, and
thereby eliminates many file system updates/writes to the flash. Windows XP Embedded Service Pack 2
Feature Pack 2007 introduced an additional write protect feature, called File Based Write Filter (FBWF).
The new FBWF function write-protects embedded devices at the file level, in contrast to the EWF, which
has been protecting devices at the sector level.
Enhanced Write Filter (EWF) feature is implemented. The EWF intercepts calls at the sector level, and
thereby eliminates many file system updates/writes to the flash. Windows XP Embedded Service Pack 2
Feature Pack 2007 introduced an additional write protect feature, called File Based Write Filter (FBWF).
The new FBWF function write-protects embedded devices at the file level, in contrast to the EWF, which
has been protecting devices at the sector level.
FBWF and EWF, combined with the built-in wear leveling algorithm, ensure that the maximum life span of
the flash device is achieved.
the flash device is achieved.