Patent ID: 8521945

Claim:
A portable data storage device, comprising: (a) an interface configured to enable the portable data storage device to transfer data to and from a host computer; (b) an interface controller configured to control the interface; and (c) a master controller configured to control writing of data to and reading data from a non-volatile memory, (d) the non-volatile memory comprising at least one single layer cell flash memory and at least one multiple layer cell flash memory, and (e) the master controller being configured to operate so that the data is simultaneously written to and simultaneously read from both of the at least one single layer cell flash memory and the at least one multiple layer cell flash memory, wherein the data is written to and read from the at least one single layer cell flash memory at a speed a multiplication factor higher than those of the at least one multiple layer cell flash memory, and wherein the multiplication factor is in the range 5 to 10.