Processor system in low power state retention mode with linear regulator off and switch regulator low in power management IC
First Claim
1. A computer-implemented method of placing a system including a processor into a low power mode, the method comprising:
- stopping running user-space processes and kernel threads executing on the processor;
saving state of the user-space processes and kernel threads in memory;
placing an input/output device coupled to the processor into a suspend mode;
configuring a wakeup source coupled to the processor to generate interrupts;
gating a clock defined in a clock gating register of the processor;
placing a linear regulator on a power management integrated circuit (PMIC) of the system into an off state;
placing a switching regulator on the PMIC into low power state;
preparing the PMIC to enter a low power mode;
setting a processor state retention mode in a clock control module coupled to the processor;
flushing a cache coupled to the processor;
disabling interrupt requests to the processor except for interrupts from the wakeup sources;
disabling processor scaling in the processor;
executing a wait for interrupt instruction configured to receive the wakeup interrupt from the wakeup source;
gating a main clock of the processor; and
placing the PMIC in the low power mode.
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Accused Products
Abstract
A quiescent state retention mode (QSRM) permits minimal power consumption and dissipation by an electronic device while idle without producing adverse latencies to users or causing system instability. Upon a call to enter the QSRM, processes may be frozen, clocks may be gated, switching regulators may be placed in low power mode, SDRAM may be placed into self-refresh mode, caches may be flushed, IRQs may be disabled, and the system waits for interrupt to wakeup. In the QSRM, powered components include the switching regulator configured to provide power to the processor is maintained in a low power mode while the SDRAM is placed in self-refresh.
30 Citations
23 Claims
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1. A computer-implemented method of placing a system including a processor into a low power mode, the method comprising:
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stopping running user-space processes and kernel threads executing on the processor; saving state of the user-space processes and kernel threads in memory; placing an input/output device coupled to the processor into a suspend mode; configuring a wakeup source coupled to the processor to generate interrupts; gating a clock defined in a clock gating register of the processor; placing a linear regulator on a power management integrated circuit (PMIC) of the system into an off state; placing a switching regulator on the PMIC into low power state; preparing the PMIC to enter a low power mode; setting a processor state retention mode in a clock control module coupled to the processor; flushing a cache coupled to the processor; disabling interrupt requests to the processor except for interrupts from the wakeup sources; disabling processor scaling in the processor; executing a wait for interrupt instruction configured to receive the wakeup interrupt from the wakeup source; gating a main clock of the processor; and placing the PMIC in the low power mode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A system of reducing power consumption in a portable electronic device, the system comprising:
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a memory; a processor coupled to the memory; a kernel stored in the memory and configured to execute on the processor, the kernel being configured to maintain a switching regulator of a power management integrated circuit (PMIC) in a low power state and a linear regulator of the PMIC in an off state while the system is in a low power mode, wherein the kernel is configured to enter the low power mode by performing the following acts; stop execution of a running user-space process and kernel thread executing on the processor; save state of the running user-space process and kernel thread to the memory; configure a wakeup source to generate an interrupt; gate a clock which is defined in a clock gating register coupled to the processor; place into the off state the linear regulator; place into the low power state the switching regulator; gate a serial peripheral interface clock or a universal serial bus clock or both which are coupled to the processor; set a state retention mode for the processor in a clock control module which is coupled to the processor; disable interrupt generation from a non-wakeup source; disable processor scaling on the processor; and gate a main clock of the processor. - View Dependent Claims (11, 12, 13, 14, 15)
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16. One or more computer-readable storage media storing instructions that, when executed by a processor, cause the processor to perform acts comprising:
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stopping running processes and threads executing on a central processing unit (CPU); saving state of the processes and threads to a memory; placing input or output or both devices into a low power or suspend state; configuring a wakeup source to generate an interrupt; gating clocks defined in clock gating register; placing into an off state a linear regulator of a power management integrated circuit (PMIC), the linear regulator configured to provide power to a gated device; placing into a low power state a switching regulator of the PMIC, the switching regulator configured to provide power to the CPU; gating a serial peripheral interface clock or a universal serial bus clock or both; setting a state retention mode for the CPU in a clock control module; disabling interrupts from a non-wakeup source; and disabling CPU scaling. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23)
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Specification