Patents by Inventor Takao Okuba

Takao Okuba has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Semiconductor memory, memory device, and memory card
    Patent number: 6016560
    Abstract: A semiconductor memory (1), having a plurality of memory blocks (2 and 3) provided with a plurality of memory cells, a data input/output buffer (7), and first control means (11) for controlling the rewriting and reading of data for the memory cells is provided with first storage means (30) for designating defective memory blocks and detection means (32) for detecting an access to a defective memory block designated by the first storage means in accordance with an address signal. When the detection means detects an access to a defective memory, the first control means inhibits the data rewrite operation for an instruction for a data rewrite operation and inhibits the output of data from the input/output buffer for the data read operation.
    Type: Grant
    Filed: March 17, 1998
    Date of Patent: January 18, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Masashi Wada, Takao Okuba, Takeshi Furuno