Stec SLUFD1GU2TUI Manual De Usuario

 

61000-07007-105, June 2011 

8 

 

In addition to the functional blocks shown in Figure 3, the Industrial Grade UFD has the following external 
components: 

  SLC NAND Flash for the most reliable data storage. 

  Crystal Oscillator 12Mhz, as the main clock source. 

Since the Industrial Grade UFD provides a standard USB interface to the host, no software integration is 
required, providing the shortest time-to-market for design engineers. 

The firmware of the embedded USB 2.0 controller contain

s STEC’s advanced flash memory management 

algorithms to ensure the most optimum device performance, reliability and endurance. It was designed to 
maximize the benefits of flash memory, while at the same time overcoming inherent NAND flash 
limitations. Implemented in firmware are the below features: 

  Flash file system management  

  Bad-block management  

  Wear-leveling  

  Performance optimization  

Inherent to NAND flash technology are areas (blocks) on the media that cannot be used for storage 
because of their high error rate. These so-

called “bad blocks” are already identified by the flash vendor 

during manufacturing, but can also be accumulated over time during device operation.  

The U2T controller contains a table that lists all the bad blocks on the device (Bad Block Table), and 
automatically maps out these blocks upon system initialization. During device operation it ensures that 
newly accumulated bad blocks are also mapped out and added to the Bad Block Table.  

Bad block management is 100% transparent to the host application, which will not be aware of the location 
or existence of bad blocks on the media.