SYSTEMS AND METHODS FOR PROVIDING EARLY HINTING TO NONVOLATILE MEMORY CHARGE PUMPS

• US 20130297852A1
• Filed: 05/02/2012
• Published: 11/07/2013
• Est. Priority Date: 05/02/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Fai, Anthony, Seroff, Nicholas C.
• Granted Patent: US 8,874,828 B2
• Time in Patent Office: Days
• US Class Current: 711/103
• CPC Class Codes: G06F 3/0625 Power saving in storage systems
• CPC Class Codes: G06F 3/0659 Command handling arrangements, e.g. command buffers, queues, command scheduling
• CPC Class Codes: G06F 3/0679 Non-volatile semiconductor memory device, e.g. flash memory, one time programmable memory [OTP]
• CPC Class Codes: G11C 16/12 Programming voltage switching circuits
• CPC Class Codes: G11C 5/145 Applications of charge pumps; Boosted voltage circuits; Clamp circuits therefor G11C5/141 takes precedence

Abstract

Systems and methods for providing early hinting to nonvolatile memory charge pumps are disclosed. Charge pumps associated with one or more nonvolatile memory dies can be proactively activated based on a determination that a command queue of access requests contains at least a threshold number of consecutive access requests of the same type. Based on analysis of the command queue, the memory controller can transmit an early hint command to a nonvolatile memory die to proactively activate its charge pump to provide a voltage suitable for executing the consecutive access requests of the same type.

Claims

1. A method comprising

receiving a set of access requests at a nonvolatile memory (“

NVM”

) system controller;

storing the access requests in a command queue;

determining that the command queue contains a number of consecutive access requests of a particular type for an NVM;

determining that the number of consecutive access requests of the particular type exceeds a predetermined threshold;

transmitting a command from the NVM system controller to the NVM to proactively activate a charge pump to a voltage suitable for executing the consecutive access requests of the particular type;

executing the consecutive access requests of the particular type; and

deactivating the charge pump.

2. The method of claim 1, wherein the access requests of a particular type are one of read commands, program commands, and erase commands.

3. The method of claim 1, wherein the NVM system controller comprises a host controller of a host device.

4. The method of claim 1, wherein the NVM system controller comprises a memory controller of an NVM package.

5. The method of claim 1, wherein the threshold value is three.

6. The method of claim 1, wherein the command transmitted to the NVM to proactively activate a charge pump is transmitted via a side-band communications channel.

7. A method for proactively activating charge pumps of a nonvolatile memory (“

NVM”

) system, the method comprising;

receiving a plurality of access requests;

storing the plurality of received access requests in a command queue;

re-queuing the plurality of received access requests to group together access requests of the same type; and

for each group of access requests of the same type;

transmitting a command to an NVM to proactively activate one or more charge pumps of the nonvolatile memory to a voltage suitable for the access request type; and

executing each access request of the group of access requests of the same type.

8. The method of claim 7, wherein the command to proactively activate one or more charge pumps is transmitted via a side-band communications channel.

9. The method of claim 7, wherein re-queuing the plurality of received access requests comprises reordering access requests within a single command queue.

10. The method of claim 7, wherein re-queuing the plurality of received access requests comprises segregating access requests of the same type into separate command queues.

11. The method of claim 7, wherein re-queuing the plurality of received access requests comprises combining access requests of the same type into a multi-access request.

12. The method of claim 7, wherein the NVM system is a multi-die NVM system.

13. The method of claim 12, further comprising re-queuing the plurality of received access requests to group together access requests based on which die of a multi-die NVM system the access requests are directed to.

14. The method of claim 7, wherein the access request types comprise at least one of:

program commands;

read commands; and

erase commands.

15. A system for providing early hinting to nonvolatile memory charge pumps, comprising:

at least one nonvolatile memory (“

NVM”

) die;

at least one charge pump associated with each of the at least one NVM die;

volatile memory comprising a command queue for storing a plurality of access requests; and

an NVM system controller communicatively coupled to the at least one charge pump and at least one NVM die, wherein the NVM system controller is configured to;

determine whether the plurality of access requests stored in the command queue comprises a number of consecutive access requests of the same type exceeding a predetermined threshold;

in response to determining that the plurality of access requests stored in the command queue contains a number of consecutive access requests of the same type exceeding a predetermined threshold, transmit a command to the at least one charge pump to generate an output voltage suitable for executing the consecutive access requests of the same type; and

dispatch the consecutive access requests of the same type to the at least one NVM die for execution.

16. The system of claim 15, wherein the at least one charge pump is external to, and communicatively coupled to, the at least one NVM memory die.

17. The system of claim 15, wherein the at least one charge pump is internal to the at least one NVM die.

18. The system of claim 15, wherein the NVM system controller is further configured to re-queue the plurality of access requests stored in the command queue to group together access requests of the same type.

19. The system of claim 15, wherein the NVM system controller is further configured to combine access requests of the same type into a multi-access request.

20. The system of claim 15, wherein the NVM system controller is further configured to segregate the plurality of access requests stored in the command queue into separate command queues.

21. The system of claim 15, further comprising a side-band communications channel between the NVM system controller and the at least one charge pump, wherein the side-band communications channel is configured to relay early hint commands from the NVM system controller to the at least one charge pump

22. The system of claim 21, wherein the command transmitted to the at least one charge pump to generate an output voltage suitable for executing the consecutive access requests of the same type is transmitted over the side-band communications channel.