Disk drive spinning down disk to a spin rate based on spin-up parameter
View Patent ↗A disk drive comprising a head actuated over a disk, and control circuitry operable to spin the disk at a first spin rate. The control circuitry is further operable to reduce the spin rate of the disk from the first spin rate to a second spin rate, wherein the second spin rate is based on a spin-up parameter associated with spinning up the disk from the second spin rate to the first spin rate. For example, the spin-up parameter may comprise one or more of a spin-up time limit, power setting, and ambient temperature.
1. A disk drive comprising:
a disk;
a head actuated over the disk; and
control circuitry operable to:
spin the disk at a first spin rate; and
reduce the spin rate of the disk from the first spin rate to a second spin rate selected from a plurality of second spin rates, wherein the second spin rate is selected based on a spin-up parameter associated with spinning up the disk from the second spin rate to the first spin rate,
wherein the spin-up parameter comprises a peak current available.
2. The disk drive as recited in claim 1 , wherein the control circuitry is further operable to receive a command from a host to enter an operating mode associated with the second spin rate.
3. The disk drive as recited in claim 2 , wherein the control circuitry is further operable to:
receive a command from the host to enter one of a plurality of operating modes; and
reduce the spin rate of the disk to one of a plurality of spin rates corresponding to the operating mode, wherein the reduced spin rate is based on the spin-up parameter.
4. The disk drive as recited in claim 3 , wherein the control circuitry is further operable to look up the reduced spin rate in response to the operating mode.
5. The disk drive as recited in claim 1 , wherein the control circuitry is further operable to compute the reduced spin rate as a function of the spin-up parameter.
6. A method of operating a disk drive comprising a head actuated over a disk, the method comprising:
spinning the disk at a first spin rate; and
reducing the spin rate of the disk from the first spin rate to a second spin rate selected from a plurality of second spin rates, wherein the second spin rate is selected based on a spin-up parameter associated with spinning up the disk from the second spin rate to the first spin rate,
wherein the spin-up parameter comprises a peak current available.
7. The method as recited in claim 6 , further comprising receiving a command from a host to enter an operating mode associated with the second spin rate.
8. The method as recited in claim 7 , further comprising:
receiving a command from the host to enter one of a plurality of operating modes; and
reducing the spin rate of the disk to one of a plurality of spin rates corresponding to the operating mode, wherein the reduced spin rate is based on the spin-up parameter.
9. The method as recited in claim 8 , further comprising looking up the reduced spin rate in response to the operating mode.
10. The method as recited in claim 6 , further comprising computing the reduced spin rate as a function of the spin-up parameter.
11. A disk drive comprising:
a disk;
a head actuated over the disk; and
control circuitry operable to:
spin the disk at a first spin rate;
reduce the spin rate of the disk from the first spin rate to a second spin rate based on a spin-up parameter associated with spinning up the disk from the second spin rate to the first spin rate;
measure an actual spin-up time to spin up the disk from the second spin rate to the first spin rate; and
adjust the second spin rate in response to the actual spin-up time.
12. The disk drive as recited in claim 11 , wherein the control circuitry is further operable to adjust the second spin rate in response to a difference between the actual spin-up time and a spin-up time limit.
13. A method of operating a disk drive comprising a head actuated over a disk, the method comprising:
spinning the disk at a first spin rate;
reducing the spin rate of the disk from the first spin rate to a second spin rate, wherein the second spin rate is based on a spin-up parameter associated with spinning up the disk from the second spin rate to the first spin rate;
measuring an actual spin-up time to spin up the disk from the second spin rate to the first spin rate; and
adjusting the second spin rate in response to the actual spin-up time.
14. The method as recited in claim 13 , further comprising adjusting the second spin rate in response to a difference between the actual spin-up time and a spin-up time limit.
15. A disk drive comprising:
a disk;
a head actuated over the disk; and
control circuitry operable to:
spin the disk at a first spin rate; and
reduce the spin rate of the disk from the first spin rate to a second spin rate selected from a plurality of second spin rates, wherein the second spin rate is selected based on a spin-up parameter associated with spinning up the disk from the second spin rate to the first spin rate,
wherein the spin-up parameter comprises an ambient temperature and a lower ambient temperature corresponds to a higher second spin rate.
16. The disk drive as recited in claim 15 , wherein the control circuitry is further operable to receive a command from a host to enter an operating mode associated with the second spin rate.
17. The disk drive as recited in claim 16 , wherein the control circuitry is further operable to:
receive a command from the host to enter one of a plurality of operating modes; and
reduce the spin rate of the disk to one of a plurality of spin rates corresponding to the operating mode, wherein the reduced spin rate is based on the spin-up parameter.
18. The disk drive as recited in claim 17 , wherein the control circuitry is further operable to look up the reduced spin rate in response to the operating mode.
19. The disk drive as recited in claim 15 , wherein the control circuitry is further operable to compute the reduced spin rate as a function of the spin-up parameter.
20. A method of operating a disk drive comprising a head actuated over a disk, the method comprising:
spinning the disk at a first spin rate; and
reducing the spin rate of the disk from the first spin rate to a second spin rate selected from a plurality of second spin rates, wherein the second spin rate is selected based on a spin-up parameter associated with spinning up the disk from the second spin rate to the first spin rate,
wherein the spin-up parameter comprises an ambient temperature and a lower ambient temperature corresponds to a higher second spin rate.
21. The method as recited in claim 20 , further comprising receiving a command from a host to enter an operating mode associated with the second spin rate.
22. The method as recited in claim 21 , further comprising:
receiving a command from the host to enter one of a plurality of operating modes; and
reducing the spin rate of the disk to one of a plurality of spin rates corresponding to the operating mode, wherein the reduced spin rate is based on the spin-up parameter.
23. The method as recited in claim 22 , further comprising looking up the reduced spin rate in response to the operating mode.
24. The method as recited in claim 20 , further comprising computing the reduced spin rate as a function of the spin-up parameter.