Semiconductor memory

Abstract

Abstract PURPOSE:To simplify writing operation control accompanied by writing confirmation by setting writing time in an internal circuit and automatically switching to a reading out mode after writing by the input of a prescribed control signal. CONSTITUTION:Nonvolatile storage elements, the threshold voltage of each of which is changed according to electric writing information, are matrix- arranged for a memory array MARY. For a control circuit CONT, an automatic verifying mode is set by a chip enable signal, the inverse of CE, and the stored data of a data latch circuit DL are written in the array MARY. The writing time is set by counting a write pulse by an output counter circuit CCTR, and the CONT is automatically switched to the reading out mode after the writing. Read out data are compared with the data stored in the latch circuit DL in a comparator circuit EOR, and the coincidence/noncoincidence between the data is decided. Thus, the writing operation control accompanied by the writing confirmation can be simplified.

Inventors

• 👤 Akinori Matsuo
• 👤 章則 松尾
• 👤 Masaru Watanabe
• 👤 優 渡辺
• 👤 Masashi Wada
• 👤 和田　正志
• 👤 Takeshi Wada
• 👤 武史 和田
• 👤 Yasuhiro Nakamura
• 👤 靖宏 中村

Bibliographic Details