Patent attributes
A host apparatus controls a memory system which has a nonvolatile semiconductor memory. The host includes an application which performs predetermined operations in accordance with a program and issues a write function invocation. A file management system has a function to allocate unit regions into which a memory area of the nonvolatile semiconductor memory is divided as a write area which stores write data, uses management units each of which is natural-number multiple times as large as the unit region as units for determining allocation, and allocates the management units as the write area in an order of realizable write speed of the management units when receiving the write function invocation. A controller issues an instruction to the memory system to write the write data into the nonvolatile semiconductor memory in accordance with an instruction by the file management system.
