Data storage device with weighting to control command selection and operating method thereof

1. A method for operating a data storage device, comprising:

determining a first weight based on the sum of data sizes for commands queued in a command queue;

determining a second weight by summing weights by types of the commands; and

controlling an urgent command selection threshold value for selecting an urgent command existing in the command queue, based on at least one of the first weight and the second weight.

2. The method according to claim 1 , further comprising, before the determining of the first weight,

determining whether a command is received from a host device.

3. The method according to claim 1 , further comprising:

checking a dirty status for a nonvolatile memory device.

4. The method according to claim 1 , wherein the urgent command selection threshold value comprises:

a first threshold value for setting a point of time for selecting the urgent command; and

a second threshold value for selecting the urgent command among the commands queued in the command queue.

5. The method according to claim 1 , wherein the urgent command selection threshold value is inversely proportional to the first weight and the second weight.

6. The method according to claim 2 , wherein the determining of the first weight is performed when a command is received from the host device.

7. The method according to claim 3 , wherein the controlling of the urgent command selection threshold value is performed by using all of the first weight, the second weight and the dirty status for the nonvolatile memory device.

8. The method according to claim 3 , wherein the controlling of the urgent command selection threshold value is performed by using at least one selected among the first weight, the second weight and the dirty status for the nonvolatile memory device.

9. The method according to claim 4 , further comprising:

determining whether the number of the commands queued in the command queue is greater than the first threshold value;

computing difference values between an age of a command queued most recently in the command queue and ages of the other commands, when the number of the commands is greater than the first threshold value;

determining whether a difference value greater than the second threshold value exists among computed difference values; and

selecting and processing a command corresponding to a corresponding difference value, as the urgent command, when the difference value greater than the second threshold value exists.

10. A data storage device comprising:

a nonvolatile memory device;

a command queue suitable for queuing commands received from a host device; and

a processor suitable for determining a first weight by summing data sizes for the commands queued in the command queue, determining a second weight by summing weights by types of the commands, and controlling an urgent command selection threshold value for selecting an urgent command existing in the command queue, based on at least one of the first weight and the second weight.

11. The data storage device according to claim 10 , wherein the processor controls the urgent command selection threshold value based on a dirty status for the nonvolatile memory device.

12. The data storage device according to claim 10 , wherein the urgent command selection threshold value comprises:

a first threshold value for setting a point of time for selecting the urgent command; and

a second threshold value for selecting the urgent command among the commands queued in the command queue.

13. The data storage device according to claim 11 , wherein the processor controls the urgent command selection threshold value by using all of the first weight, the second weight and the dirty status for the nonvolatile memory device.

14. The data storage device according to claim 11 , wherein the processor controls the urgent command selection threshold value by using at least one selected among the first weight, the second weight and the dirty status for the nonvolatile memory device.

15. The data storage device according to claim 12 , wherein the processor determines whether the number of the commands queued in the command queue is greater than the first threshold value, and computes difference values between an age of a command queued most recently in the command queue and ages of the other commands, when the number of the commands is greater than the first threshold value.

16. The data storage device according to claim 15 , wherein the processor determines whether a difference value greater than the second threshold value exists among computed difference values, and selects and processes a command corresponding to a corresponding difference value, as the urgent command, when a difference value greater than the second threshold value exists.