Patent ID: 8671257

Claim:
A memory system comprising: a memory configured to be accessed via a first number of channels; a memory interface configured to access the memory in parallel via the first number of channels; a valid-cluster search module configured to sequentially search valid clusters included in first blocks, in each of the channels, for compaction in which the valid clusters are migrated from the first blocks to a second block; a read command generator configured to generate read commands used to read, in parallel, valid clusters to be migrated to the second block, wherein the valid clusters searched in each of the channels comprise the valid clusters to be migrated, and the valid clusters to be migrated correspond to a number of clusters simultaneously written to the second block and to a second number of channels in the first number of channels; a command issue module configured to issue the read commands to the memory interface via the second number of channels; and a determination module configured to determine the second number of channels corresponding to read commands to be generated next based on a situation of issuance of the read commands.