Panasonic Corporation

Koichi Horiuchi

Manabu Inoue

Yoshiho Gotoh

Shinji Inoue

Takuji Maeda

Masahiro Nakanishi

Tetsushi Kasahara

Kazuaki Tamura

Tomoaki Izumi

Kiminori Matsuno

Shoichi Tsujita

Jun Ohara

Makoto Ochi

A card information-storing portion is provided in a semiconductor memory card, and information relating to access performance such as access condition and access rate is held in the storing portion. Further, an access device acquires the held information from the semiconductor memory card to make it possible that the information can be used for control of a file system. This optimizes processing of the access device and the semiconductor memory card independent of differences in characteristics of semiconductor memory cards and management methods used, realizing high-rate access from the access device to a semiconductor memory card.

Semiconductor memory card, access device and method

A host information memory is provided in a semiconductor memory card and a data write start address and a data size supplied by an access unit are stored. A free physical area generation section determines whether or not to perform erasing of an invalid block of a nonvolatile memory when writing of data based on the data write start address and data size, and determines the number of blocks to be erased. When erasing, writing of data and erasing of invalid blocks are simultaneously performed with respect to different memory chips. Erase process of data, herewith, can be optimized and high speed access from the access unit to a semiconductor memory card can be realized.

Semiconductor memory card, semiconductor memory control apparatus, and semiconductor memory control method

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Nara, Japan

Koichi Horiuchi