The memory controller and memory access method

The microcomputer (10), all sectors in each sector segment which is divided plurality under a predetermined condition, in a flash memory (20), to hold the group definition table associating different memory area respectively (132). Memory controller (120) specifies by referring to the group definition table memory area corresponding to the designated sector (132), a range of the specified memory area, the physical address corresponding to the designated sector Search for. The memory control unit (120), when the rewriting of the data corresponding to the specified sector occurs, to move the sectors within the range of the memory area.