Semiconductor memory device
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsRyu Makabe, Masaki Tsukude, Hirotoshi Sato, Shinichi Kobayashi
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Abstract
Successive data read access with a final address specified is detected by a command mode detecting circuit to set a command mode entry status. In the command mode entry, a command of designating an internal state is made acceptable in accordance with a predetermined external signal. Consequently, a semiconductor memory device that enters a command mode, maintaining compatibility of pins and signal timings with a conventional static memory is provided.
Claims17
A semiconductor memory device comprising:
- mode detecting circuitry for detecting that a predetermined set of external signals are applied in a combination of specific logic states successively a predetermined number of times;
- and
- mode setting circuitry for setting a specific mode in response to a detection signal from said mode detecting circuitry.
A semiconductor memory device accessed in accordance with external signals in a normal operation mode, comprising
- a command decoder made active in a specific mode, for decoding predetermined external signals out of said external signals and generating a signal for setting an internal state to a predetermined state when activated, said signal generated by said command decoder being a signal for designating an operation related to a standby status of said semiconductor memory device.
A semiconductor memory device accessed in accordance with external signals in a normal operation mode, comprising:
- mode detecting circuitry for detecting that a predetermined set of external signals out of said external signals are applied in a combination of specific logic states a predetermined number of times successively;
- mode setting circuitry for setting a specific mode in response to a detection signal of said mode detecting circuitry;
- and
- mode circuitry rendered operable in said specific mode in accordance with an output signal of said mode setting circuitry.
Dependencies are inferred from the claim text.