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US 12,626,747 B2Granted
Semiconductor memory device selectively performing self-refresh operation and self-refresh method thereof
AssigneeSamsung Electronics Co., Ltd.
InventorsYoungjae Park, Soomin Kim, Yuchan Kim, Dongha Kim, Hyunbo Kim
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Abstract
A self-refresh method of a semiconductor memory device includes: receiving a self-refresh entry command associated with a self-refresh operation; counting an elapsed time from a time of receiving the self-refresh entry command; and skipping the self-refresh operation depending on whether a self-refresh exit command is received before the counted elapsed time exceeds a reference time.
Claims18
A self-refresh method of a semiconductor memory device, comprising:
- receiving a self-refresh entry command associated with a self-refresh operation;
- counting an elapsed time from a time of receiving the self-refresh entry command;
- skipping the self-refresh operation depending on whether a self-refresh exit command is received before the counted elapsed time exceeds a reference time;
- and
- counting a number of times the self-refresh operation is continuously skipped.
2 more elements
A semiconductor memory device, comprising:
- a cell array including a plurality of dynamic-random-access-memory (DRAM) cells;
- a command decoder configured to decode a command associated with a self-refresh operation to output a self-refresh entry command and a self-refresh exit command;
- a control circuit configured to generate a control signal to skip the self-refresh operation when a time difference between a reception time of the self-refresh entry command and a reception time of the self-refresh exit command is shorter than a reference time, wherein the control circuit comprises an oscillator duty cycle controller configured to select a period according to a mode register set command and comprising:
- a lookup table including a plurality of period settings, and
- a multiplexer configured to select one of the plurality of period setting values in response to a mode register set command to output the period;
- and
- a refresh controller configured to perform one of i) the self-refresh operation on a selected memory area of the cell array and ii) the skip of the self-refresh operation, in response to the control signal.
4 more elements
A self-refresh method of a semiconductor memory device, comprising:
- receiving a self-refresh entry command associated with a self-refresh operation;
- delaying the self-refresh operation by a reference time in response to the self-refresh entry command;
- detecting whether a self-refresh exit command is input before an elapsed time from receipt of the self-refresh entry command reaches a reference time;
- skipping the self-refresh operation when the self-refresh exit command is received before the elapsed time reaches the reference time;
- and
- counting a number of times the self-refresh operation is continuously skipped.
3 more elements
Dependencies are inferred from the claim text.