Valid context status retention in processor power mode management

摘要

A system having multiple power mode types, for example, includes a power manager that is responsive to a selection of a suspend power mode type for maintaining processor context information in volatile memory while the processor is in the selected suspend mode. A status register is arranged to retain the status of the context information in the volatile memory while the processor is in the selected suspend power mode. The power manager is arranged to selectively apply power to various voltage domains in response to the type of power mode selected. The processor is optionally arranged to signal the power manager of transitions to the selected suspend mode and of transitions to an active mode using a power enable signal.

主权项

1. A system, comprising:
a volatile memory for storing and accessing information, wherein the volatile memory consumes power in a first voltage domain when storing and accessing the information; a processor for writing the information to and reading the information from the volatile memory, wherein the processor consumes power in a second voltage domain when writing the information to and reading the information from the volatile memory, and wherein the processor is arranged to store a context of the processor as context information in the volatile memory in response to an indication of a transition to a first suspend mode type; a status register for storing a valid context indication for determining whether a valid processor context of the processor has been stored in the volatile memory, wherein the status register consumes power in a third voltage domain when storing the valid context indication for determining whether a valid processor context of the processor has been stored in the volatile memory; a power manager for selectively coupling power to the first, second, and third voltage domains in response to an indication of a transition to an active mode, for decoupling power to the first, second, and third voltage domains in response to an indication of a transition to an off mode, and for coupling power to the first and third voltage domains and decoupling power to the second voltage domain in response to an indication of a transition to the first suspend mode type, and; a program loader for restoring the processor context from the volatile memory in response to determining, by reading the stored valid context indication, whether a valid processor context of the processor has been stored.