Patent Application
20080155280
The present disclosure generally relates to the field of electronics. More particularly, an embodiment of the invention relates to reducing leakage power in an integrated circuit (IC) device using an external agent.
Power consumption, both dynamic and leakage, is one of the major concerns of IC design. In particular, leakage power may be growing with each successive design generation. One popular power saving technique implemented in notebook computers is to use ICs that can operate in a state or mode of reduced work capability that leads to reduced power consumption.
Some processors can operate according to an internal core clock signal that can be on/off modulated. This is an example of processor clock “throttling” which temporarily puts the processor in a non-active mode, which, in turn significantly reduces processor power consumption. A broader set of power states or work capability modes have been defined to place the processor in various sleep states. In a sleep state, some or all of the computing and I/O functions of the processor are essentially shut down.
However, current designs generally place their I/Os on a separate voltage plane and leave them powered up at all times. The present disclosure addresses this and other issues in reducing idle leakage power to these I/Os that are powered up at all times.
Various features of the invention will be apparent from the following description of preferred embodiments as illustrated in the accompanying drawings, in which like reference numerals generally refer to the same parts throughout the drawings. The drawings are not necessarily to scale, the emphasis instead being placed upon illustrating the principles of the inventions.
In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the various aspects of the invention. However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the invention may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.
In current systems, software directs the system to reduce power to the core when entering sleep state. During sleep state, the voltage may be below retention and perhaps 0V. Current designs generally place their I/Os on a separate voltage plane and leave the I/Os powered up at all times. Thus, the I/Os always consume power and leak power. The present invention is a method of reducing power by cutting power to I/Os during times the package is in an idle state.
For example, if the package 105 contained 200 I/O pins, 180 pins (115) would be turned off during sleep state and the other 20 I/O pins (110) would remain on at all times to wake up the other 180 pins AUX 115. The I/O pins each have their own voltage source VI/O 112 and Vaux 135, respectively. It should be noted that the amount of I/O pins are for illustration purposes only and that this number may vary depending on the design of the system.
A chipset in a system is aware of the current state of the package 105. Thus, when the package enters a low power state, such as a sleep state, the chipset notifies external circuitry 125 to cut power to the I/O pins AUX 115 through a signal 130. This external circuitry may be an external FET. Upon exiting the sleep state, the chipset enables the external circuit through the signal 130 and voltage 135 to the I/O pins AUX 115 is restored.
The portion of the I/O pins 110 that always remain on may notify the external circuitry to go ahead and cut off power to the subset of I/O pins AUX 115 upon receiving the signal 215. This signal could come from the I/O pins 110 or from another chip. For example, in one embodiment when the system goes into low power mode, the chipset is aware of the system mode, and the chipset notifies the gating circuitry.
Upon the system waking up from low power mode, a signal is sent from the chipset to the external circuitry to power up 220. Upon receiving the power up signal, the I/O pins 110 enables the external circuitry to power up the subset of I/O pins 115 upon receiving the signal 225.
The present implementation is discussed using external circuitry. However, an on die FET could also control turning on and off the I/O pins AUX 115. The control logic may be on the die, or generated from another die in the system.
Alternatively, the implementation of
Accordingly, the coverage of this implementation may be board enough to cover traditional voltage planes to account for variance in voltage ramp time or required need for that resource. For example, although the operating system control indicates a core should be woken from an idle state, this may be done in stages to limit in-rush current.
This allows hardware, either internal or external to the device, to ramp voltage to various functions differently (at different times or different rates) in order to reduce in-rush current, increase energy efficiency, and leave off portions until demand dictates a need for that logic. Hardware could power up a die in stages to reduce in-rush current such as powering up a core at a time, or delaying restoring power to memory controllers and I/O until after core's have complete state restore.
Furthermore, hardware could delay restoring power to specialized functions until demand or performance dictated a need. A vector processoring unit or last level cache (LLC) could remain powered up unbeknownst to software until hardware detects that those functions are required to meet performance or functional goals.
A chipset 33 may also communicate with the interconnection network 49. The chipset 33 may include a memory control hub (MCH) 34. The MCH 34 may include a memory controller 36 that communicates with a memory 41. The memory 41 may store data and sequences of instructions that are executed by the CPU 31, or any other device included in the computing system 300. In one embodiment of the invention, the memory 41 may include one or more volatile storage (or memory) devices such as random access memory (RAM), dynamic RAM, (DRAM), synchronous DRAM (SDRAM), static RAM (SRAM), or the like. Nonvolatile memory may also be utilized such as a hard disk. Additional devices may communicate via the interconnection network 49, such as multiple CPUs and/or multiple system memories.
The MCH 34 may also include a graphics interface 37 that communicates with a graphics accelerator 42. In one embodiment of the invention, the graphics interface 37 may communicate with the graphics accelerator 42 via an accelerated graphics poet (AGP). In an embodiment of the invention, a display (such as a flat panel display) may communicate with the graphics interface 37 through, for example, a signal converter that translates a digital representation of an image stored in a storage device such as a video memory or system memory into display signals that are interpreted and displayed by the display. The display signals produced by the display device may pass through various control devices before being interpreted by and subsequently displayed on the display.
A hub interface 51 may allow the MCH 34 to communicate with an input/output control hub (ICH) 38. The ICH 38 may provide an interface to I/O devices that communicate with components of the computing system 300. The ICH 38 may communicate with a bus 47 through a peripheral bridge (or controller) 39, such as a peripheral component interconnect (PCI) bridge, a universal serial bus (USB) controller, or the like. The bridge 39 may provide a data path between the CPU 31 and peripheral devices. Other types of topologies may be utilized. Also, multiple buses may communicate with the ICH 38, e.g. through multiple bridges or controllers. Moreover, other peripheral in communication with the ICH 38 may include, in various embodiments of the invention, integrated drive electronics (IDE) or small computer system interfaces (SCSI) hard drive(s), USB ports, a keyboard, a mouse, parallel port(s), serial port(s), floppy disk drive(s), digital output support (e.g., digital video interface (DVI)), or the like.
The bus 47 may communicate with an audio device 43, one or more disk drive(s) 44, and a network interface device 46 (which communicates with the computer network 48). Other devices may be in communication with the bus 47. Also, various components (such as the network interface device 46) may be in communication with the MCH 34 in some embodiments of the invention. In addition, the processor 31 and the MCH 34 may be combined to form a single chip. Furthermore, the graphics accelerator 42 may be included within the MCH 34 in other embodiments of the invention.
Furthermore, the computing system 300 may include volatile and/or nonvolatile memory (or storage). For example, nonvolatile memory may include one or more of the following: read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically EPROM (EEPROM), a disk drive (e.g., 44) a floppy disk, a compact disk ROM (CD-ROM), a digital versatile disk (DVD), flash memory, a magneto-optical disk, or other types of nonvolatile machine-readable media capable of storing electronic instructions and/or data.
As illustrated in
The processors 5, 10 may be any type of a processor such as those discussed with reference to the processors 31 of
At least one embodiment of the invention may be provided within the processors 5, 10. For example, one or more of the processor core (s) 32 may be located within the processors 5, 10. Other embodiments of the invention, however, may exist in other circuits, logic units, or devices with the system 400 of
The chipset 50 may communicate with a bus 16 using a PtP interface circuit 95. The bus 16 may have one or more devices that communicate with it, such as a bus bridge 18 and I/O devices 14. Via a bus 20, the bus bridge 14 may be in communication with other devices such as a keyboard/mouse 22, communication devices 26 (such as modems, network interface devices, etc. that may be in communication with the computer network 48), audio I/O devices, and/or a data storage device 28. The data storage device 28 may store code 30 that may be executed by the processors 5 and/or 10.
In various embodiments of the invention, the operations discussed herein, e.g., with reference to
Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least an implementation. The appearances of the phrase “in one embodiment” in various places in the specification may or may not be all referring to the same embodiment.
Also, in the description and claims, the term “coupled” and “connected”, along with their derivatives, may be used. In some embodiments of the invention, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements may not be in direct contact with each other, but may still cooperate or interact with each other.
Thus, although embodiments have been described in language specific to structural features and/or methodological acts, it is to be understood that claimed subject matter may not be limited to the specific features or acts described. Rather, the specific features and acts are disclosed as sample forms of implementing the claimed subject matter.
