Memory devices and methods of controlling an auto-refresh operation of the memory devices
A memory device includes a memory medium and a memory controller. The memory medium has a memory cell array and may be configured to generate a self-refresh signal, which varies based on an internal temperature of the memory medium, to control a self-refresh operation performed on the memory cell array. The memory controller may be configured to calculate an auto refresh cycle of an auto refresh control signal for controlling an auto-refresh operation of the memory medium based on the self-refresh signal.
1. A memory device comprising:
a memory medium including a self-refresh controller, the self-refresh controller configured to control the performance of a self-refresh operation based on a self-refresh cycle varying according to an internal temperature of the memory medium; and
a memory controller configured to generate an auto refresh control signal for an auto-refresh operation performed by the memory medium based on an auto-refresh cycle, the auto-refresh cycle determined by a self-refresh signal received from the memory medium, the self-refresh signal varied based on the internal temperature of the memory medium,
wherein the self-refresh cycle is determined by comparing the self-refresh signal with a clock signal.
2. The memory device of claim 1 ,
wherein the memory medium includes a plurality of output pins, and
wherein the self-refresh signal is transmitted to the memory controller through and unused pin among the plurality of output pins of the memory medium.
3. The memory device of claim 1 , wherein the self-refresh controller includes:
a temperature sensor configured to output a voltage signal having a voltage level corresponding to the internal temperature of the memory medium;
a voltage adjustment oscillator configured to generate a base clock signal, a frequency of the base clock signal varying according to the voltage level of the voltage signal;
a self-refresh cycle adjuster configured to apply a predetermined division factor to the base clock signal to generate the self-refresh signal; and
an address counter configured to receive the self-refresh signal to generate a self-refresh address.
4. The memory device of claim 1 , wherein the memory controller includes:
a self-refresh cycle counter configured to receive the self-refresh signal to generate a counted value by comparing the self-refresh signal with the clock signal;
a temperature information converter configured to receive the counted value to generate a temperature code corresponding to the counted value; and
an auto-refresh controller configured to generate the auto refresh control signal for the auto-refresh operation performed by the memory medium based on the auto-refresh cycle varying according to the temperature code.
5. The memory device of claim 4 , wherein the self-refresh signal is a one-bit pulse signal.
6. The memory device of claim 4 , wherein the temperature information converter includes a storage table that stores the temperature code having a binary number form which is set to correspond to the counted value.
7. The memory device of claim 4 , wherein the auto-refresh controller reduces the auto-refresh cycle if the temperature code increases and increases the auto-refresh cycle if the temperature code is reduced.
8. A method of controlling an auto-refresh operation of a memory device, the method comprising:
performing a self-refresh operation based on a self-refresh cycle varying according to an internal temperature of a memory medium;
generating a self-refresh signal in the memory medium;
generating an auto-refresh signal having an auto-refresh cycle determined from the self-refresh signal varied by the internal temperature; and
transmitting an auto-refresh control signal to the memory medium such that the memory medium performs the auto-refresh operation based on the auto-refresh cycle,
wherein the auto-refresh control signal includes the auto-refresh signal, and
wherein the self-refresh cycle is determined by comparing the self-refresh signal with a clock signal.
9. The method of claim 8 , wherein generating the auto-refresh signal includes:
generating a counted value corresponding to a cycle of the self-refresh signal; and
generating the auto-refresh signal having the auto-refresh cycle varying according to a temperature code corresponding to the counted value.
10. A memory device comprising:
a memory medium including a memory cell array and configured to generate a self-refresh signal, which varies based on an internal temperature of the memory medium, to control a self-refresh operation performed on the memory cell array; and
a memory controller configured to calculate an auto refresh cycle of an auto refresh control signal for controlling an auto-refresh operation of the memory medium based on the self-refresh signal,
wherein the self-refresh cycle is determined by comparing the self-refresh signal with a clock signal.
11. The memory device of claim 10 ,
wherein the memory medium includes a plurality of output pins, and
wherein the self-refresh signal is transmitted to the memory controller through an unused pin among the plurality of output pins of the memory medium.
12. The memory device of claim 10 ,
wherein the memory medium includes a self-refresh controller,
wherein the self-refresh controller includes:
a temperature sensor configured to output a voltage signal having a voltage level corresponding to the internal temperature of the memory medium;
a voltage adjustment oscillator configured to generate a base clock signal, a frequency of the base clock signal varying according to the voltage level of the voltage signal;
a self-refresh cycle adjuster configured to apply a predetermined division factor to the base clock signal to generate the self-refresh signal; and
an address counter configured to receive the self-refresh signal to generate a self-refresh address.
13. The memory device of claim 10 , wherein the memory controller includes:
a self-refresh cycle counter configured to receive the self-refresh signal to generate a counted value by comparing the self-refresh signal with the clock signal;
a temperature information converter configured to receive the counted value to generate a temperature code corresponding to the counted value; and
an auto-refresh controller configured to generate the auto refresh control signal for the auto-refresh operation performed by the memory medium based on the auto-refresh cycle varying according to the temperature code.
14. The memory device of claim 13 , wherein the self-refresh signal is a one-bit pulse signal.
15. The memory device of claim 13 , wherein the temperature information converter includes a storage table that stores the temperature code having a binary number form which is set to correspond to the counted value.
16. The memory device of claim 13 , wherein the auto-refresh controller reduces the auto-refresh cycle if the temperature code increases and increases the auto-refresh cycle if the temperature code is reduced.