Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Shoichi Tsujita

Manabu Inoue

Yoshiho Gotoh

Shinji Inoue

Takuji Maeda

Masahiro Nakanishi

Tetsushi Kasahara

Kazuaki Tamura

Tomoaki Izumi

Kiminori Matsuno

Jun Ohara

Koichi Horiuchi

Makoto Ochi

Hiroshi Sakurai

Tsutomu Sekibe

Hideki Kawai

Tatsuhiro Hosokawa

Masaru Fujii

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

A communication interface of the present invention includes a clock signal line, a first signal line, a second signal line and one or more data signal lines as communication signal lines between a master system and a slave system.

Communication interface having a master activating/deactivating a first signal with a clock signal after a predetermined time after a slave activating/deactivating the first signal

Growing community of inventors

Kyoto, Japan

Shoichi Tsujita