Abstract: A memory device for storing data includes a memory cell and a test cell. The memory cell is configured to indicate a data value based on a threshold voltage of the memory cell. The test cell is configured to indicate a validity rating of the data value stored in the memory cell. The validity rating is determined after exposure to an environmental condition such as high temperatures and/or X-ray radiation. The validity rating is based on a test shift from an initial threshold voltage of the test cell prior to exposure to the environmental condition to a shifted threshold voltage of the test cell test cell after exposure to the environmental condition. The validity rating is characterized as invalid when the test shift is greater than a threshold value.

Abstract: A method of operating a controller to decompress a compressed data file stored on a host computer, and store the resulting uncompressed data in a flash memory. The processor loads compressed data into random access memory (RAM) until a predetermined amount of compressed data is present in the RAM. The controller then decompresses compressed data retrieved from the RAM until a decompressed amount of decompressed data equals a block size corresponding to a minimum modulus size of the flash memory, where the minimum size block of data that can be written to the flash memory because of the design of the flash memory. The controller then transfers the block of decompressed data to the flash memory. These steps are repeated in a coordinated fashion until the entire compressed data file has been downloaded from the host computer, decompressed by the controller, and stored in the flash memory.