Switches coupling volatile memory devices to a power source

• US 10,289,181 B2
• Filed: 04/29/2014
• Issued: 05/14/2019
• Est. Priority Date: 04/29/2014
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Inventors: Bolt, Matthew T.
• Primary Examiner(s): Birkhimer, Christopher D
• Application Number:
  US15/303,472
• Publication Number:
  US 20170031408A1
• Time in Patent Office: 1,841 Days
• CPC Class Codes: G06F 1/263 Arrangements for using multiple switchable power supplies, e.g. battery and AC G06F1/30 takes precedence
• CPC Class Codes: G06F 1/28 Supervision thereof, e.g. detecting power-supply failure by out of limits supervision
• CPC Class Codes: G06F 3/0619 in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 Replication mechanisms
• CPC Class Codes: G06F 3/0685 Hybrid storage combining heterogeneous device types, e.g. hierarchical storage, hybrid arrays
• CPC Class Codes: G11C 11/4074 Power supply or voltage generation circuits, e.g. bias voltage generators, substrate voltage generators, back-up power, power control circuits
• CPC Class Codes: G11C 5/04 Supports for storage elements , e.g. memory modules; Mounting or fixing of storage elements on such supports
• CPC Class Codes: G11C 5/148 Details of power up or power down circuits, standby circuits or recovery circuits
• CPC Class Codes: G11C 8/12 Group selection circuits, e.g. for memory block selection, chip selection, array selection

Abstract

Example implementations relate to coupling volatile memory devices to a power source. In example implementations, data may be copied from a first volatile memory device on a memory module to non-volatile memory. The first volatile memory device may cease to be powered after data is copied from the first volatile memory device to non-volatile memory. After the first volatile memory device has ceased to be powered, data may be copied from a second volatile memory device on the memory module to non-volatile memory. The second volatile memory device may cease to be powered after data is copied from the second volatile memory device to non-volatile memory.

Claims

1. A system comprising:

a first volatile memory device;

a second volatile memory device;

a first switch connected to the first volatile memory device;

a second switch connected to the second volatile memory device, wherein each of the first and second switches, when closed, couples the respective volatile memory device to a power source; and

a controller communicatively coupled to the first and second volatile memory devices and the first and second switches, wherein the controller is to;

open the first switch after data is copied from the first volatile memory device to non-volatile memory, and while the second switch is closed; and

copy data from the second volatile memory device to the non-volatile memory after the first switch is opened.

2. The system of claim 1, wherein:

the first and second switches comprise first and second field-effect transistors (FETs), respectively; and

the controller is to control gate voltages of the first and second FETs.

3. The system of claim 1, wherein the power source comprises a battery or a supercapacitor.

4. The system of claim 1, wherein the controller comprises a field programmable gate array (FPGA) or a double data rate (DDR) buffer.

5. The system of claim 1, further comprising:

a third volatile memory device; and

a third switch connected to the third volatile memory device, wherein;

the power source is a backup power source;

the first, second, and third volatile memory devices are coupled to the backup power source when a main power source ceases to power the first, second, and third volatile memory devices;

the third switch, when closed, couples the third volatile memory device to the backup power source;

the controller is to open the second switch after data is copied from the second volatile memory device to the non-volatile memory and while the third switch is closed; and

data is copied from the third volatile memory device to the non-volatile memory after the second switch is opened.

16. The system of claim 1, wherein opening the first switch after data is copied comprises opening the first switch in response to a determination that that a first copy of the data from the first volatile memory to the non-volatile memory is complete.

17. The system of claim 1, wherein opening the first switch causes the first volatile memory device to cease to be powered.

18. The system of claim 5, wherein opening the second switch after data is copied comprises opening the second switch in response to a determination that that a second copy of the data from the second volatile memory to the non-volatile memory is complete.

19. The system of claim 5, wherein opening the second switch causes the second volatile memory device to cease to be powered.

20. The system of claim 1, wherein the power source comprises a main power source and a backup power source.

6. A memory module controller comprising instructions that cause the memory module controller to:

close a plurality of switches on a memory module, wherein;

each of the plurality of switches is connected to a respective one of a plurality of volatile memory devices on the memory module; and

each of the plurality of switches, when closed, couples the respective volatile memory device to a power source;

copy data from the plurality of volatile memory devices to non-volatile memory; and

open each of the plurality of switches after data is copied from the respective volatile memory device to the non-volatile memory, wherein;

switches connected to volatile memory devices, whose data has already been copied to the non-volatile memory, are open while switches connected to volatile memory devices, whose data has not yet been copied to the non-volatile memory, are closed.

7. The memory module controller of claim 6, wherein:

the power source is a backup power source; and

the plurality of volatile memory devices are coupled to the backup power source when a main power source ceases to power the plurality of volatile memory devices.

8. The memory module controller of claim 6, further comprising instructions that cause the memory module controller to:

determine whether copying of data from one of the plurality of volatile memory devices to the non-volatile memory has been completed; and

transmit, in response to a determination that copying of data from the one of the plurality of volatile memory devices to the non-volatile memory has been completed, a command to open the respective switch connected to the one of the plurality of volatile memory devices.

9. The memory module controller of claim 6, wherein the plurality of switches comprise field-effect transistors (FETs), the memory module controller further comprising instructions that cause the memory module controller to:

determine whether copying of data from one of the plurality of volatile memory devices to the non-volatile memory has been completed; and

change, in response to a determination that copying of data from the one of the plurality of volatile memory devices to the non-volatile memory has been completed, a gate voltage of a FET connected to the one of the plurality of volatile memory devices.

10. The memory module controller of claim 6, wherein the power source comprises a battery or a supercapacitor.

11. The memory module controller of claim 6, wherein the plurality of volatile memory devices comprises dynamic random-access memory (DRAM) devices.

12. A method comprising:

copying data from a first volatile memory device on a memory module to non-volatile memory;

ceasing to power the first volatile memory device after data is copied from the first volatile memory device to the non-volatile memory while powering a second volatile memory device on the memory module;

copying, after the first volatile memory device has ceased to be powered, data from the second volatile memory device on the memory module to the non-volatile memory; and

ceasing to power the second volatile memory device after data is copied from the second volatile memory device to the non-volatile memory.

13. The method of claim 12, wherein:

the first and second volatile memory devices are connected to first and second switches, respectively;

each of the first and second switches, when closed, couples the respective volatile memory device to a power source;

ceasing to power the first volatile memory device comprises opening the first switch; and

ceasing to power the second volatile memory device comprises opening the second switch.

14. The method of claim 13, wherein each of the first and second switches comprises a field-effect transistor (FET), the method further comprising:

determining whether copying of data from one of the first and second volatile memory devices to the non-volatile memory has been completed; and

changing, in response to a determination that copying of data from the one of the first and second volatile memory devices to the non-volatile memory has been completed, a gate voltage of a FET connected to the one of the first and second volatile memory devices.

15. The method of claim 12, wherein the power source is a backup power source, the method further comprising:

powering the first and second volatile memory devices and a third volatile memory device with the backup power source when a main power source is disconnected from the first, second, and third volatile memory devices;

copying, after the second volatile memory device has ceased to be powered, data from the third volatile memory device to the non-volatile memory; and

ceasing to power the third volatile memory device after data is copied from the third volatile memory device to the non-volatile memory.