Precise power cycle management in data storage devices
Methods and apparatus for precise power cycle management in data storage devices are provided. One such apparatus is a data storage device that includes a non-volatile memory (NVM) and a processor coupled to the NVM. In such case, the processor is configured to determine a first peak power for a first power phase, operate the DSD at a first DSD power consumption that is less than the first peak power for the first power phase, determine a second peak power for a second power phase based on a residual power equal to a difference between a preselected average power threshold and the first DSD power consumption, and operate the DSD at a second DSD power consumption that is less than the second peak power for the second power phase.
1. A data storage device (DSD), the DSD comprising:
a non-volatile memory (NVM); and
one or more processors coupled to the NVM, the one or more processors, individually or in combination, configured to:
set a first peak power for a first power phase to a fixed value;
operate the DSD at a first DSD power consumption that is less than the first peak power for the first power phase;
determine a second peak power for a second power phase based on a first residual power equal to a difference between a preselected average power threshold and the first DSD power consumption;
determine a second phase time period based on the first residual power;
operate the DSD in the second power phase at a second DSD power consumption that is less than the second peak power for the second phase time period;
determine a second residual power based on the first residual power plus a difference between the average power threshold and the second DSD power consumption;
set a third peak power equal to the first peak power;
operate the DSD at a third DSD power consumption for a third power phase, wherein the third DSD power consumption is less than the third peak power;
determine a third residual power based on the second residual power plus a difference between the average power threshold and the third DSD power consumption;
determine a fourth peak power based on the third residual power;
determine a fourth phase time period based on the third residual power; and
operate the DSD at a fourth DSD power consumption that is less than the fourth peak power for the fourth power phase.
2. The data storage device of claim 1 :
wherein the one or more processors, individually or in combination, is further configured to determine a power cost for entry into, and exit from, the second power phase; and
wherein the second DSD power consumption is based on the residual power and the power cost.
3. The data storage device of claim 2 , wherein the one or more processors, individually or in combination, is further configured to determine the second phase time period further based on the power cost.
4. The data storage device of claim 1 , wherein the residual power is a negative value.
5. The data storage device of claim 1 , wherein the one or more processors, individually or in combination, is further configured to:
receive commands from a host device; and
execute the commands using the NVM.
6. The data storage device of claim 1 , wherein the one or more processors, individually or in combination, is further configured to alternate peak power values over a plurality of subsequent power phases between the fixed value and adjustable values determined, at least in part, based on a most recent residual power value.
7. A method for use with a data storage device (DSD) including a non-volatile memory (NVM), the method comprising:
setting a first peak power for a first power phase to a fixed value;
operating the DSD at a first DSD power consumption that is less than the first peak power for the first power phase;
determining a second peak power for a second power phase based on a first residual power equal to a difference between a preselected average power threshold and the first DSD power consumption;
determining a second phase time period based on the first residual power;
operating the DSD in the second power phase at a second DSD power consumption that is less than the second peak power for the second phase time period;
determining a second residual power based on the first residual power plus a difference between the average power threshold and the second DSD power consumption;
setting a third peak power equal to the first peak power;
operating the DSD at a third DSD power consumption for a third power phase, wherein the third DSD power consumption is less than the third peak power;
determining a third residual power based on the second residual power plus a difference between the average power threshold and the third DSD power consumption;
determining a fourth peak power based on the third residual power;
determining a fourth phase time period based on the third residual power; and
operating the DSD at a fourth DSD power consumption that is less than the fourth peak power for the fourth power phase.
8. The method of claim 7 , further comprising:
determining a power cost for entry into, and exit from, the second power phase; and
wherein the second DSD power consumption is based on the residual power and the power cost.
9. The method of claim 8 , further comprising:
determining the second phase time period further based on the power cost.
10. The method of claim 7 , further comprising alternating peak power values over a plurality of subsequent power phases between the fixed value and adjustable values determined, at least in part, based on a most recent residual power value.
11. A data storage device (DSD), the DSD comprising:
a non-volatile memory (NVM); and
one or more processors coupled to the NVM, the one or more processors, individually or in combination, configured to:
provide a sequence of alternating first and second power phases;
operate the DSD during the first power phases at a DSD power consumption that is less than a preselected fixed peak power, wherein the first power phases each have a preselected fixed duration; and
operate the DSD during the second power phases at a DSD power consumption that is less than a variable peak power determined based on (a) a preselected average power threshold, (b) an actual power consumption of the previous first power phase, and (c) a residual power that is accumulated over one or more previous first and second power phases, and wherein the second power phases have variable durations determined based on the residual power.
12. The data storage device of claim 11 , wherein the first power phases are even-numbered power phases and the second power phases are odd-numbered power phases.
13. The data storage device of claim 11 :
wherein the one or more processors, individually or in combination, is further configured to determine a power cost for entry into, and exit from, the second power phases; and
wherein the DSD power consumption for the second power phases is further based on the residual power and the power cost.
14. The data storage device of claim 13 , wherein the one or more processors, individually or in combination, is further configured to determine the variable durations of the second phase based on the power cost and the residual power.
15. The data storage device of claim 11 , wherein the residual power is a negative value.
16. The data storage device of claim 11 , wherein the one or more processors, individually or in combination, is further configured to:
receive commands from a host device; and
execute the commands using the NVM.
17. A method for use with a data storage device (DSD) including a non-volatile memory (NVM), the method comprising
providing a sequence of alternating first and second power phases;
operating the DSD during the first power phases at a DSD power consumption that is less than a preselected fixed peak power, wherein the first power phases each have a preselected fixed duration; and
operating the DSD during the second power phases at a DSD power consumption that is less than a variable peak power determined based on (a) a preselected average power threshold, (b) an actual power consumption of the previous first power phase, and (c) a residual power that is accumulated over one or more previous first and second power phases, and wherein the second power phases have variable durations determined based on the residual power.
18. The method of claim 17 , wherein the first power phases are even-numbered power phases and the second power phases are odd-numbered power phases.
19. The method of claim 17 , further comprising:
determining a power cost for entry into, and exit from, the second power phases; and
wherein the DSD power consumption for the second power phases is further determined based on the residual power and the power cost.
20. The method of claim 19 , further comprising determining the variable durations of the second phase based on the power cost and the residual power.
21. An apparatus for use with a data storage device (DSD) including a non-volatile memory (NVM), the apparatus comprising
means for providing a sequence of alternating first and second power phases;
means for operating the DSD during the first power phases at a DSD power consumption that is less than a preselected fixed peak power, wherein the first power phases each have a preselected fixed duration; and
means for operating the DSD during the second power phases at a DSD power consumption that is less than a variable peak power determined based on (a) a preselected average power threshold, (b) an actual power consumption of the previous first power phase, and (c) a residual power that is accumulated over one or more previous first and second power phases, and wherein the second power phases have variable durations determined based on the residual power.