Method to detect power loss through data storage device spindle speed
A method for detecting power loss on a data storage device (DSD) includes: as part of a device initialization of the DSD, measuring a rotational speed of a spindle of a rotating media; comparing the measured spindle rotational speed to a threshold rotational speed value; and based on the comparison, determining whether the device initialization has been triggered due to a power-on reset of the DSD.
1. A method for detecting power loss on a data storage device (DSD), the method comprising:
as part of a device initialization of the DSD, measuring a rotational speed of a spindle of a rotating media;
comparing the measured spindle rotational speed to a threshold rotational speed value; and
based on the comparison, determining whether the device initialization has been triggered due to a power-on reset of the DSD,
wherein the method is performed under the control of a processor.
2. The method of claim 1 , further comprising:
in response to a determination that the measured spindle rotational speed is equal to or greater than the threshold rotational speed value, incrementing a count of a power-loss counter.
3. The method of claim 2 , wherein the count of the power-loss counter is stored in nonvolatile storage.
4. The method of claim 2 , wherein the count of the power-loss counter is stored on the rotating media.
5. The method of claim 1 , further comprising:
in response to a determination that the measured spindle rotational speed is less than the threshold rotational speed value, incrementing a count of a power-on reset counter.
6. The method of claim 1 , wherein the threshold rotational speed value is based on a rotational speed difference from an operational rotational speed of the spindle.
7. The method of claim 1 , wherein the threshold rotational speed value is adjustable.
8. A data storage device (DSD), comprising:
rotating media;
a spindle configured to cause the rotating media to rotate;
a rotational speed sensor configured to sense a rotational speed of the spindle as part of a device initialization of the DSD;
a power-loss counter configured to count power-loss events; and
a control unit configured to:
determine the rotational speed of the spindle based on a signal from the rotational speed sensor;
compare the determined rotational speed of the spindle to a threshold rotational speed value; and
based on the comparison, determine whether the device initialization has been triggered due to a power-on reset of the DSD.
9. The DSD of claim 8 , wherein in response to a determination that the spindle rotational speed is equal to or greater than the threshold rotational speed value, the control unit is further configured to increment a count of the power-loss counter.
10. The DSD of claim 9 , further comprising:
nonvolatile storage,
wherein the control unit is further configured to store the count of the power-loss counter in the nonvolatile storage.
11. The DSD of claim 9 , wherein the control unit is further configured to store the count of the power-loss counter on the rotating media.
12. The DSD of claim 8 , further comprising:
a power-on reset counter,
wherein in response to a determination that the spindle rotational speed is less than the threshold rotational speed value, the control unit is further configured to increment a count of the power-on reset counter.
13. A non-transitory computer readable medium having stored therein a program for making a processor execute a method for detecting power loss on a data storage device (DSD), said program including executable instructions for performing operations comprising:
as part of a device initialization of the DSD, measuring by the processor a rotational speed of a spindle of a rotating media;
comparing by the processor the measured spindle rotational speed to a threshold rotational speed value; and
based on the comparison, determining by the processor whether the device initialization has been triggered due to a power-on reset of the DSD.
14. The non-transitory computer readable medium having stored therein a program as defined in claim 13 , the program further comprising executable instructions for performing operations including:
in response to a determination that the spindle rotational speed is equal to or greater than the threshold rotational speed value, incrementing a count of a power-loss counter.
15. The non-transitory computer readable medium having stored therein a program as defined in claim 14 , the program further comprising executable instructions for performing operations including:
storing the count of the power-loss counter in nonvolatile storage.
16. The non-transitory computer readable medium having stored therein a program as defined in claim 14 , the program further comprising executable instructions for performing operations including:
storing the count of the power-loss counter on the rotating media.
17. The non-transitory computer readable medium having stored therein a program as defined in claim 13 , the program further comprising executable instructions for performing operations including:
in response to a determination that the spindle rotational speed is less than the threshold rotational speed value, incrementing a count of a power-on reset counter.
18. The non-transitory computer readable medium having stored therein a program as defined in claim 13 , the program further comprising executable instructions for performing operations including:
determining the threshold rotational speed value based on a rotational speed difference from an operational rotational speed of the spindle.
19. An apparatus for detecting power loss duration on a data storage device (DSD), the apparatus comprising:
a control unit configured to, as part of a device initialization of the DSD:
measure a rotational speed of a spindle of a rotating media;
compare the measured spindle rotational speed to a plurality of successively lower threshold rotational speed values corresponding to successively longer time durations; and
determine a power loss duration based on comparisons of the measured spindle rotational speed with the plurality of successively lower threshold rotational speed values.
20. The apparatus of claim 19 , wherein the control unit is further configured to:
in response to a determination that the measured spindle rotational speed is greater than one of the successively lower threshold rotational speed values:
store a time duration corresponding to an immediately preceding threshold rotational speed value as a power loss duration, and
increment a count of a power-loss counter.
21. The apparatus of claim 20 , wherein the control unit is further configured to store the count of the power-loss counter in nonvolatile storage.
22. The apparatus of claim 20 , wherein the control unit is further configured to store the count of the power-loss counter on the rotating media.
23. The apparatus of claim 19 , wherein the control unit is further configured to:
in response to a determination that the measured spindle rotational speed is less than a minimum threshold rotational speed value, incrementing a count of a power-on reset counter.
24. The apparatus of claim 19 , wherein the successively lower threshold rotational speed values are based on rotational speed differences from an operational rotational speed of the spindle.