Memory device and control method thereof
A method of controlling a memory device including a temperature sensor includes sensing a temperature of the memory device and extracting an extracted temperature for controlling the memory device using the sensed temperature, storing the extracted temperature in the memory device, calculating an estimated temperature at a current time point using the extracted temperature and a plurality of past extracted temperatures stored in the memory device, and controlling the memory device using the estimated temperature.
1. A method of controlling a memory device comprising a temperature sensor, the method comprising:
sensing a temperature of the memory device, and extracting an extracted temperature for controlling the memory device using the sensed temperature;
storing the extracted temperature in the memory device;
calculating an estimated temperature at a current time point using the extracted temperature and a plurality of past extracted temperatures stored in the memory device; and
controlling the memory device using the estimated temperature,
wherein calculating estimated temperature comprises:
calibrating the extracted temperature and the plurality of past extracted temperatures by an extraction delay time that is consumed from the sensing of the temperature of the extracting of the extracted temperature.
2. The method of claim 1 , wherein calculating the estimated temperature further comprises:
determining the estimated temperature using the calibrated extracted temperature and the calibrated plurality of past extracted temperatures.
3. The method of claim 2 , wherein determining the estimated temperature comprises:
determining a tendency according to time in the calibrated extracted temperature and the calibrated plurality of past extracted temperatures; and
calculating the estimated temperature corresponding to the current time point according to the determined tendency.
4. The method of claim 3 , wherein determining the tendency comprises:
using a tendency line according to time of the calibrated extracted temperature and the calibrated plurality of past extracted temperatures.
5. The method of claim 1 , wherein controlling the memory device comprises:
determining a higher temperature between the extracted temperature and the estimated temperature as a calibrated temperature and controlling the memory device using the calibrated temperature.
6. The method of claim 5 , wherein in the controlling of the memory device,
when a change rate of the calibrated temperature according to time is higher than a threshold change rate, the change rate in the calibrated temperature is limited to the threshold change rate.
7. The method of claim 1 , wherein in the controlling of the memory device,
when the extracted temperature is lower than a predetermined critical temperature, a lower temperature between the extracted temperature and the estimated temperature is determined as a calibrated temperature, and the memory device is controlled using the calibrated temperature.
8. The method of claim 1 , further comprising:
calculating a section average temperature using the extracted temperature and the plurality of past extracted temperatures,
wherein the memory device is controlled using the extracted temperature, the estimated temperature, and the section average temperature.
9. The method of claim 1 , further comprising:
generating a calibrated temperature for the controlling of the memory device, using the extracted temperature and the estimated temperature; and
outputting the calibrated temperature to an outside of the memory device.
10. The method of claim 1 , wherein controlling the memory device comprises controlling a refresh cycle of the memory device using the estimated temperature.
11. A memory device, comprising:
at least one memory cell array;
a temperature sensor configured to sense a temperature of the memory device;
a control logic circuit configured to receive the sensed temperature from the temperature sensor, generate an extracted temperature of the memory device using the sensed temperature, generate a calibrated temperature by calibrating the extracted temperature and a plurality of past extracted temperatures along a time axis and determining a tendency according to time in the calibrated extracted temperature and the calibrated plurality of past extracted temperatures, and control operations of the at least one memory cell array using the calibrated temperature; and
a register configured to store the extracted temperature and the plurality of past extracted temperatures and provide the plurality of past extracted temperatures stored in the temperature register to the control logic circuit.
12. The memory device of claim 11 , wherein the control logic circuit comprises:
a temperature extractor configured to receive the sensed temperature and generate the extracted temperature using the sensed temperature;
a temperature processing unit configured to generate the calibrated temperature using the extracted temperature and the plurality of past extracted temperatures; and
an operation controller configured to control operations of the at least one memory cell array using the calibrated temperature,
wherein the temperature processing unit comprises a temperature calculator configured to calculate at least one piece of temperature information for generating the calibrated temperature using the extracted temperature and the plurality of past extracted temperatures.
13. The memory device of claim 12 , wherein the temperature calculator comprises:
a temperature estimator configured to calibrate a time axis in a negative time direction by an extraction delay time with respect to the extracted temperature and the plurality of past extracted temperatures, and calculate an estimated temperature at a current time point using the extracted temperature and the plurality of past extracted temperatures having the calibrated time axis.
14. The memory device of claim 12 , wherein the temperature calculator comprises:
a section average temperature calculator configured to calculate a section average temperature based on the extracted temperature and the plurality of past extracted temperatures.
15. The memory device of claim 12 , wherein the temperature calculator generates a first rate of change in temperatures using the extracted temperature and the plurality of past extracted temperatures, and
the temperature processing unit further comprises;
a temperature selector configured to generate the calibrated temperature having a rate of change substantially identical to a threshold change rate when the first rate of change in temperatures is greater than the threshold change rate.
16. The memory device of claim 12 , wherein
the temperature processing unit determines a higher temperature between the extracted temperature and the at least one piece of temperature information as the calibrated temperature.
17. A method of determining a temperature of a memory device, the method comprising:
sensing, by at least one temperature sensor, a temperature of the memory device;
extracting the temperature of the memory device using the sensed temperature;
generating an estimated temperature at a current time point using the extracted temperature and a plurality of past extracted temperatures stored in the memory device; and
determining a calibrated temperature of the memory device using the estimated temperature and the extracted temperature,
wherein when the extracted temperature and the estimated temperature over a period of time are plotted in a graph as a plurality of extracted temperatures and a plurality of estimated temperatures, the plurality of extracted temperatures represent a curve that is substantially parallel and shifted in a positive time direction by an extraction delay time on a time axis with respect to a plurality of real temperatures of the memory device, and the plurality of estimated temperatures represent a curve that is closer to the plurality of real temperatures than the plurality of extracted temperatures.
18. The method of claim 17 , wherein
determining the calibrated temperature comprises:
determining a higher temperature between the estimated temperature and the extracted temperature as the calibrated temperature.
19. The method of claim 17 , wherein in the determining of the calibrated temperature,
when a change rate of the calibrated temperature according to time is higher than a threshold change rate, the change rate of the calibrated temperature is limited to the threshold change rate.
20. The method of claim 17 , wherein a refresh cycle of the memory device is controlled to be shorter as the calibrated temperature increases.