MD3331-D64-V3-X SanDisk, MD3331-D64-V3-X Datasheet - Page 30

• Manufacturer Part Number: MD3331-D64-V3-X
• Manufacturer: SanDisk
• Type: Flash Diskr

Specifications of MD3331-D64-V3-X

• Density: 64MByte
• Operating Supply Voltage (typ): 3.3V
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Package Type: FBGA
• Mounting: Surface Mount
• Pin Count: 69
• Operating Temperature Classification: Industrial
• Operating Supply Voltage (min): 2.5V
• Operating Supply Voltage (max): 3.6V
• Programmable: Yes
• Lead Free Status / Rohs Status: Not Compliant

6.1.1
The TrueFFS driver is integrated into all major OSs, including Symbian OS, Windows CE, Pocket
PC, Smartphone, OSE, Nucleus, and others. For a complete listing of all available drivers, please
refer to M-Systems’ website www.m-systems.com. It is advised to use the latest driver versions that
can be downloaded from the Mobile DiskOnChip Plus web page on the M-Systems site.
6.1.2
The basic TrueFFS Software Development Kit (SDK) provides the source code of the TrueFFS
driver. It can be used in an OS-less environment or when special customization of the driver is
required for proprietary OSs.
When using Mobile DiskOnChip Plus as the boot replacement device, the TrueFFS SDK also
incorporates in its source code the BDK, software that is required for this configuration (this
package is also available separately). Please refer to the DiskOnChip Boot Software Development
Kit (BDK) developer guide for further information on using this software package.
6.1.3
TrueFFS accesses the flash memory within Mobile DiskOnChip Plus through an 8KB window in
the CPU memory space. It provides block device API, by using standard file system calls, identical
to those used by a mechanical hard disk, to enable reading from and writing to any sector on Mobile
DiskOnChip Plus. This makes it compatible with any file system and file system utilities such as
diagnostic tools and applications. When using the File Allocation Table (FAT) file system, the data
stored on Mobile DiskOnChip Plus uses FAT-16.
Mobile DiskOnChip Plus is shipped unformatted and contains virgin media.
6.1.4
As NAND flash is an imperfect storage media, it contains some bad blocks that cannot be used for
storage because of their high error rates. TrueFFS automatically detects and maps bad blocks upon
system initialization, ensuring that they are not used for storage. This management process is
completely transparent to the user, who remains unaware of the existence and location of bad
blocks, while remaining confident of the integrity of data stored. The Bad Block Table on Mobile
DiskOnChip Plus is hardware-protected for ensured reliability.
6.1.5
Flash memory can be erased a limited number of times. This number is called the erase cycle limit
or write endurance limit and is defined by the flash array vendor. The erase cycle limit applies to
each individual erase block in the flash device. In Mobile DiskOnChip Plus, the erase cycle limit of
the flash is 300,000 erase cycles. This means that after approximately 300,000 erase cycles, the
erase block begins to make storage errors at a rate significantly higher than the error rate that is
typical to the flash.
In a typical application and especially if a file system is used, a specific page or pages are constantly
updated (e.g., the page/s that contain the FAT, registry etc.). Without any special handling, these
pages would wear out more rapidly than other pages, reducing the lifetime of the entire flash.
30
Built-In Operating System Support
TrueFFS Software Development Kit (SDK)
File Management
Bad-Block Management
Wear-Leveling
Data Sheet, Rev. 1.8
Mobile DiskOnChip Plus 16/32MByte
95-SR-000-10-8L