Semiconductor disk device and memory management method

摘要

A semiconductor disk device includes an interface that connects to a host unit operating under DOS; a flash memory having at least one continuous data storage area for storing data; a control circuit that controls data input/output with the host unit through the interface and that manages addresses of the main memory, and a cache memory connected to the control circuit and accessible to the main memory through the control circuit. Data files supplied from the host unit are written in the data storage area beginning at the lowest available address and a directory entry file associated with a data file is written into the data storage area immediately following and contiguous to the data file. Additional data and directory entry files are similarly stored sequentially. Thus, the disk device can operate with a host unit transferring data in sector units but without using a file allocation table or transformation table to maintain correlation of logical sector addresses and physical sector addresses of the stored data files in the flash memory.