Other

Renesas Technology Corp.

Shinichi Sawamura

Toru Owada

Yoshiaki Eguchi

Naoko Iwami

Takayuki Tamura

Takashi Totsuka

Yasushi Akao

Nagamasa Mizushima

Shinichi Kato

Jun Kitahara

Yasushi Nagai

Isao Takita

Itaru Nonomura

Takeshi Asahi

The external storage device according to the present invention which uses a non-volatile semiconductor memory such as a flash memory is provided with plural areas which store user data, and restricts access to the user data from a host computer and also dynamically changes an area an access to which is to be restricted. Accordingly, the ease of use of the external storage device for the host computer is improved. Specifically, the interior of the flash memory is divided into a normal area not protected by a password or the like and a protected area protected by a password or the like. A microprocessor controls accesses to the normal area and the protected area in accordance with a command from the host computer. In addition, the host computer can access the protected area after passing through authentication using a password. Moreover, the host computer changes information indicative of the location of the protected area, thereby dynamically changing the protection area.

External storage device using non-volatile semiconductor memory

A system which serves both as a host and a device cannot be realized with a single connector due to the constitution of hardware in the prior art. The prior art system only detects the existence of a device and cannot distinguish between a host and a device while a power source is turned on and switch its function. The information processing apparatus of the present invention separates the data lines of a host communication controller and the data lines of a device communication controller and activates the selected controller by means of selecting the data lines of the controllers and means of determining which is connected to a connector, a host or a device.

Information processing apparatus

Growing community of inventors

Kawasaki, Japan

Shinichi Sawamura