MEMORY FRAGMENT ELIMINATION (DEFRAGMENTATION) OF CHIP CARD

摘要

PROBLEM TO BE SOLVED: To enable defragmentation while keeping the rules of power failure resistance by a 100 percent by alternately using two sets of descriptors so as to define the positions of a source and a target of copying operation. SOLUTION: A pointer controller 32 carries out a defragmentating process for a memory device 34 consisting of pages 35 by using the back-trace buffer function of an intermediate buffer 36. At this time, effective data blocks are copied as a series of chunks in the memory device 34 sequentially in steps. Then two sets including three descriptors are used alternately to define the copy destination positions of the source and target of 1st copying operation for copy chunks and the copy destination position of 2nd copying operation and the descriptors of at least one set are used to hold information for restoring the copy chunk contents if a power disconnection is made in the copying operation for the copy chunks.