Patent ID: 7783851

Claim:
A method of operating a non-volatile memory device that includes a first data block that stores first data and a first log block that stores an updated version of at least some of the first data, the method comprising: copying valid portions of the first data in the first data block to a free block that has no data to generate a second data block; copying the updated version of at least some of the first data from the first log block to the second data block; designating the first log block as a reusable log block without erasing the data therefrom in response to at least one predetermined condition being satisfied; recording an updated version of at least some of the data stored in the second data block or a third data block into clean memory of the first log block after the first log block is designated as a reusable log block, wherein the first, second and third data blocks are different data blocks, wherein designating the first log block as a reusable log block without erasing the data therefrom in response to at least one predetermined condition being satisfied comprises: determining an amount of clean memory in the first log block; comparing the determined amount of clean memory with a predetermined reference value; and designating the first log block as a reusable log block without erasing the data therefrom based on the determined amount of clean memory in the first log block exceeding the predetermined reference value.