Nonvolatile semiconductor disk device limiting a number of simultaneous transfers and associated control process

摘要

Write data, when given from a host via an interface, are temporarily stored in a buffer memory of a disk control unit. A number-of-chips managing unit manages the number of memory chips executing writing operations. If the number of memory chips in the process of writing operations does not reach a fixed number, the write data are transferred to the memory chips allocated to, corresponding write areas. Whereas if the number of memory chips in the process of writing operations reaches the fixed number, the write data are transferred after an end of the writing operations to the memory chips in the process of writing operations. An entire electric current during the writing operation of a disk card can be thereby restricted.