Memory access management for low-power use cases of a system on chip via secure non-volatile random access memory

• US 10,591,975 B2
• Filed: 10/30/2017
• Issued: 03/17/2020
• Est. Priority Date: 10/30/2017
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Li, Yanru, Touzni, Azzedine, Chun, Dexter Tamio
• Primary Examiner(s): Abbaszadeh, Jaweed A
• Assistant Examiner(s): Pandey, Keshab R
• Application Number:
  US15/798,116
• Publication Number:
  US 20190129493A1
• Time in Patent Office: 869 Days
• CPC Class Codes: G06F 1/3243 Power saving in microcontroller unit
• CPC Class Codes: G06F 1/3246 by software initiated power-off
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: G06F 15/7817 Specially adapted for signal processing, e.g. Harvard architectures
• CPC Class Codes: G06F 21/575 Secure boot
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/81 by operating on the power supply, e.g. enabling or disabling power-on, sleep or resume operations
• CPC Class Codes: G06F 9/4403 Processor initialisation
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

Systems and methods are disclosed for managing memory access for low-power use cases of a system on chip. One such method comprises booting a system on chip (SoC) comprising a plurality of SoC processing devices. A trusted channel is created to a secure non-volatile random access memory (NVRAM). The method determines a power-saving software program to be executed on the SoC by one of the plurality of SoC processing devices. A software image associated with the power-saving software program is loaded to the secure NVRAM. In response to loading the software image to the secure NVRAM, each of the plurality of SoC processing devices except the one executing the software image from the secure NVRAM are powered down.

Claims

1. A method for managing memory access for low-power use cases of a system on chip, the method comprising:

booting a system on chip (SoC) comprising a plurality of SoC processing devices, the SoC comprising a circuit board with the plurality of SoC processing devices mounted thereon;

creating a trusted channel to a secure non-volatile random access memory (NVRAM) the secure NVRAM located off-chip relative to the SoC;

determining a power-saving software program to be executed on the SoC by one of the plurality of SoC processing devices by assessing a hint received from the power-saving software program and assessing a trait about the power-saving software program, each hint corresponding to a fixed value and each trait comprising a measurement made by hardware about the power-saving software program;

loading a software image associated with the power-saving software program from volatile memory to the secure NVRAM; and

in response to loading the software image to the secure NVRAM, powering down each of the plurality of SoC processing devices except the one executing the software image from the secure NVRAM.

2. The method of claim 1, wherein the hint comprises one or more of a software image size, a bandwidth, a power value, and a boot speed.

3. The method of claim 1, wherein the software image is loaded to the secure NVRAM from volatile memory comprising a double data rate (DDR) memory electrically coupled to the SoC.

4. The method of claim 3, wherein the software image is loaded to the DDR memory by a central processing unit during runtime or the booting of the SoC.

5. The method of claim 1, wherein the plurality of SoC processing devices comprise one of a central processing unit (CPU), a graphics processing unit (GPU), and a digital signal processor, each mounted on the circuit board.

6. The method of claim 5, wherein the power-saving software program is to be executed by the digital signal processor and, in response to loading the software image to the secure NVRAM, each of the plurality of SoC processing devices are powered down except the digital signal processor.

7. The method of claim 1, wherein the SoC is incorporated in a mobile phone.

8. The method of claim 1, wherein the secure NVRAM comprises a fuse having a pass gate value.

9. A system for managing low-power use cases of a system on chip, the system comprising:

means for booting a system on chip (SoC) comprising a plurality of SoC processing devices, the SoC comprising a circuit board with the plurality of SoC processing devices mounted thereon;

means for creating a trusted channel to a secure non-volatile random access memory (NVRAM), the secure NVRAM located off-chip relative to the SoC;

means for determining a power-saving software program to be executed on the SoC by one of the plurality of SoC processing devices by assessing a hint received from the power-saving software program and assessing a trait about the power-saving software program, each hint corresponding to a fixed value and each trait comprising a measurement made by hardware about the power-saving software program;

means for loading a software image associated with the power-saving software program from volatile memory to the secure NVRAM; and

means for powering down each of the plurality of SoC processing devices except the one executing the software image from the secure NVRAM in response to loading the software image to the secure NVRAM.

10. The system of claim 9, wherein the hint comprises one or more of a software image size, a bandwidth, a power value, and a boot speed.

11. The system of claim 9, wherein the software image is loaded to from volatile memory the secure NVRAM from a double data rate (DDR) memory electrically coupled to the SoC.

12. The system of claim 11, wherein the software image is loaded to the DDR memory by a central processing unit during runtime or the booting of the SoC.

13. The system of claim 9, wherein the plurality of SoC processing devices comprise one of a central processing unit (CPU), a graphics processing unit (GPU), and a digital signal processor, each mounted on the circuit board.

14. The system of claim 13, wherein the power-saving software program is to be executed by one of the digital signal processor and the CPU and, in response to loading the software image to the secure NVRAM, each of the plurality of SoC processing devices are powered down except the one of the digital signal processor and the CPU.

15. The system of claim 9, wherein the SoC is incorporated in a mobile phone.

16. The system of claim 9, wherein the secure NVRAM comprises a fuse having a pass gate value.

17. A system for managing memory access for low-power use cases of a system on chip, the system comprising:

a system on chip (SoC) comprising a plurality of SoC processing devices, the SoC comprising a circuit board with the plurality of SoC processing devices mounted thereon;

a double data rate (DDR) memory electrically coupled to the SoC;

a secure non-volatile random access memory (NVRAM) having a fuse with a pass gate value for creating a trusted channel; and

a low-power use case management module comprising logic configured to;

determine a power-saving software program to be executed on the SoC by one of the plurality of SoC processing devices by assessing a hint received from the power-saving software program and assessing a trait about the power-saving software program, each hint corresponding to a fixed value and each trait comprising a measurement made by hardware about the power-saving software program;

load a software image associated with the power-saving software program from the DDR memory to the secure NVRAM; and

in response to loading the software image to the secure NVRAM, initiating a powering down of each of the plurality of SoC processing devices except the one executing the software image from the secure NVRAM.

18. The system of claim 17, wherein the hint comprises one or more of a software image size, a bandwidth, a power value, and a boot speed.

19. The system of claim 17, wherein the software image is loaded to the DDR memory by a central processing unit during runtime or booting of the SoC.

20. The system of claim 17, wherein the plurality of SoC processing devices comprise one of a central processing unit (CPU), a graphics processing unit (GPU), and a digital signal processor, each mounted on the circuit board.

21. The system of claim 20, wherein the power-saving software program is to be executed by the digital signal processor and, in response to loading the software image to the secure NVRAM, each of the plurality of SoC processing devices are powered down except the digital signal processor.

22. The system of claim 17, wherein the SoC is incorporated in a mobile phone.

23. A computer program embodied in a non-transitory computer-readable medium and executable by a processor for managing memory access for low-power use cases of a system on chip, the computer program comprising logic configured to:

boot a system on chip (SoC) comprising a plurality of SoC processing devices, the SoC comprising a circuit board with the plurality of SoC processing devices mounted thereon;

create a trusted channel to a secure non-volatile random access memory (NVRAM) the secure NVRAM located off-chip relative to the SoC;

determine a power-saving software program to be executed on the SoC by one of the plurality of SoC processing devices by assessing a hint received from the power-saving software program and assessing a trait about the power-saving software program, each hint corresponding to a fixed value and each trait comprising a measurement made by hardware about the power-saving software program;

load a software image associated with the power-saving software program from volatile memory to the secure NVRAM; and

in response to loading the software image to the secure NVRAM, power down each of the plurality of SoC processing devices except the one executing the software image from the secure NVRAM.

24. The computer program of claim 23, wherein the plurality of SoC processing devices comprise one of a central processing unit (CPU), a graphics processing unit (GPU), and a digital signal processor.

25. The computer program of claim 23, wherein the power-saving software program is to be executed by the digital signal processor and, in response to loading the software image to the secure NVRAM, each of the plurality of SoC processing devices are powered down except the digital signal processor.

26. The computer program of claim 23, wherein the SoC is incorporated in a mobile phone.