Systems and methods for reducing volatile memory standby power in a portable computing device

Patent metadata

Field	Value
Publication number	US-9632562-B2
Application number	US-201514616720-A
Country	US
Kind code	B2
Filing date	Feb 8, 2015
Priority date	Nov 20, 2014
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

Various embodiments of systems and methods are disclosed for reducing volatile memory standby power in a portable computing device. One such method involves receiving a request for a volatile memory device to enter a standby power mode. One or more compression parameters are determined for compressing content stored in a plurality of banks of the volatile memory device. The stored content is compressed based on the one or more compression parameters to free-up at least one of the plurality of banks. The method disables self-refresh of at least a portion of one or more of the plurality of banks freed-up by the compression during the standby power mode.

First claim

What is claimed is:

1. A method for reducing volatile memory standby power in a portable computing device, the method comprising:
receiving a request for a volatile memory device to enter a standby power mode;
determining in response to the request one or more compression parameters for compressing content stored in a plurality of banks of the volatile memory device, the one or more compression parameters specifying a number of the plurality of banks to be compressed;
compressing the stored content associated with the number of the plurality of banks specified by the one or more compression parameters to free-up at least one of the plurality of banks; and
disabling self-refresh of at least a portion of one or more of the plurality of banks freed-up by the compression during the standby power mode.

2. The method of claim 1 , wherein the compression parameters further comprise one or more of a size of a compression block and a spill-over bank.

3. The method of claim 2 , wherein the compressing the stored content further comprises writing compressed spill-over content to the spill-over bank.

4. The method of claim 1 , further comprising storing compression metadata identifying a first block to be retrieved when decompressing the compressed content.

5. The method of claim 1 , wherein the disabling self-fresh comprises disabling self-refresh of one or more bank segments or one or more of the plurality of banks.

6. The method of claim 1 , wherein the volatile memory device comprises double data rate (DDR) memory.

7. The method of claim 6 , wherein the DDR memory comprises low power DDR (LPDDR) memory.

8. The method of claim 1 , wherein the portable computing device comprises one of a mobile phone and a wearable device.

9. The method of claim 1 , further comprising:
storing a compression status for the plurality of banks in a finite state machine.

10. The method of claim 9 , further comprising:
storing, in the finite state machine, a content block size and a start address for each compressed content block in the volatile memory device.

11. A system for reducing volatile memory standby power in a portable computing device, the system comprising:
means for receiving a request for a volatile memory device to enter a standby power mode;
means for determining in response to the request one or more compression parameters for compressing content stored in a plurality of banks of the volatile memory device, the one or more compression parameters specifying a number of the plurality of banks to be compressed;
means for compressing the stored content associated with the number of the plurality of banks specified by the one or more compression parameters to free-up at least one of the plurality of banks; and
means for disabling self-refresh of at least a portion of one or more of the plurality of banks freed-up by the compression during the standby power mode.

12. The system of claim 11 , wherein the compression parameters further comprise one or more of a size of a compression block and a spill-over bank.

13. The system of claim 12 , further comprising:
means for writing compressed spill-over content to the spill-over bank.

14. The system of claim 11 , further comprising:
means for storing compression metadata identifying a first block to be retrieved when decompressing the compressed content.

15. The system of claim 14 , wherein the means for disabling self-fresh comprises means for disabling self-refresh of one or more bank segments or one or more of the plurality of banks.

16. The system of claim 11 , wherein the volatile memory device comprises double data rate (DDR) memory.

17. The system of claim 16 , wherein the DDR memory comprises one of graphics DDR (GDDR) memory and low power DDR (LPDDR) memory.

18. The system of claim 11 , wherein the portable computing device comprises one of a mobile phone and a wearable device.

19. The system of claim 11 , further comprising:
means for storing a compression status for the plurality of banks in a finite state machine.

20. The system of claim 19 , further comprising:
means for storing, in the finite state machine, a content block size and a start address for each compressed content block in the volatile memory device.

21. A computer program embodied in a non-transitory computer-readable medium and executable by a processor for reducing volatile memory standby power in a portable computing device, the computer program comprising logic configured to:
receive a request for a volatile memory device to enter a standby power mode;
determine in response to the request one or more compression parameters for compressing content stored in a plurality of banks of the volatile memory device, the one or more compression parameters specifying a number of the plurality of banks to be compressed;
compress the stored content associated with the number of the plurality of banks specified by the one or more compression parameters to free-up at least one of the plurality of banks; and
disable self-refresh of at least a portion of one or more of the plurality of banks freed-up by the compression during the standby power mode.

22. The computer program of claim 21 , wherein the compression parameters further comprise one or more of a size of a compression block and a spill-over bank.

23. The computer program of claim 22 , wherein the logic configured to compress the stored content further comprises logic configured to write compressed spill-over content to the spill-over bank.

24. The computer program of claim 21 , further comprising:
logic configured to store compression metadata identifying a first block to be retrieved when decompressing the compressed content.

25. The computer program of claim 24 , wherein the logic configured to disable self-fresh comprises logic configured to disable self-refresh of one or more bank segments or one or more of the plurality of banks.

26. A system for reducing volatile memory standby power in a portable computing device, the system comprising:
a dynamic random access memory (DRAM) device comprising a plurality of banks containing memory content; and
a DRAM controller coupled to the DRAM device, the DRAM controller comprising a DRAM compression component configured to bypass an address interleave component, the DRAM compression component comprising logic configured to:
receive a request for the DRAM device to enter a standby power mode;
determine in response to the request one or more compression parameters for compressing the memory content stored in the plurality of banks, the one or more compression parameters specifying a number of the plurality of banks to be compressed;
compress the memory content associated with the number of the plurality of banks specified by the one or more compression parameters to free-up at least one of the plurality of banks; and
disable self-refresh of at least a portion of one or more of the plurality of banks freed-up by the compression during the standby power mode.

27. The system of claim 26 , wherein the compression parameters further comprise one or more of a size of a compression block and a spill-over bank.

28. The system of claim 27 , wherein the logic configured to compress the memory content further comprises logic configured to write compressed spill-over content to the spill-over bank.

29. The system of claim 26

Assignees

• Qualcomm Inc

Inventors

• Quach Nhon Toai
• Deepak Virat
• Arias Oscar Cabral
• Li Yanru
• Lo Haw-Jing
• Drop Michael
• Pinnamaraju Durga Venkata Narayana Ramesh
• Khan Moinul

Classifications

• G11C11/409

  Read-write [R-W] circuits · CPC title

• G06F1/3275 Primary

  Power saving in memory, e.g. RAM, cache · CPC title

• Y02B60/1282

  Cross-Sectional Technologies · mapped topic

• H03M7/30

  Compression (speech analysis-synthesis for redundancy reduction G10L19/00; for image communication H04N); Expansion; Suppression of unnecessary data, e.g. redundancy reduction · CPC title

• G06F2212/1028

  Power efficiency · CPC title