Circuit and method for selecting test self-refresh period of semiconductor memory device
AssigneeHynix Semiconductor Inc.
InventorKyong-Ha Lee
Life of this patent
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Abstract
The present invention provides a self-refresh period adaptable for testing cells that are weak against hot temperature stress. An apparatus for controlling a self-refresh operation in a semiconductor memory device includes a first period selector for generating one of a period-fixed pulse signal having a constant period and a period-variable pulse signal having a variable period based on a temperature of the semiconductor memory device in a test mode; and a self-refresh block for performing the self-refresh operation in response to an output of the first period selector.
Claims15
An apparatus for controlling a self-refresh operation in a semiconductor memory device, comprising:
- a first period selector for outputting a period-fixed pulse signal having a constant period when a temperature of the semiconductor memory device increases more than a predetermined degree and outputting a period-variable pulse signal having a variable period based on the temperature when the temperature is below the predetermined degree in a test mode;
- and
- a second period selector for outputting one of the period-variable pulse signal and the period-fixed pulse signal according to a operating option in a test exit mode.
An apparatus for controlling a self-refresh operation in a semiconductor memory device, comprising:
- a first period selector for outputting one of a period-fixed pulse signal having a constant period and a period-variable pulse signal having a variable period based on a temperature of the semiconductor memory device,
- wherein the first period selector outputs the period-fixed pulse signal when the temperature of the semiconductor memory device increases more than a predetermined degree in a test mode.
An apparatus for controlling a self-refresh operation in a semiconductor memory device, comprising:
- a first period selector for outputting one of a period-fixed pulse signal having a constant period and a period-variable pulse signal having a variable period based on a temperature of the semiconductor memory device in a test made;
- a second period selector for outputting one of the period-variable pulse signal and the period-fixed pulse signal according to an operating option in a test exit mode, and
- a self-refresh block for performing the self refresh operation in response to outputs of the first and second period selector.
Dependencies are inferred from the claim text.