Apple Inc.

Richard H Larson

Shih-Chieh Wen

Richard F Russo

John H Kelm

Charles J Fleckenstein

John H Mylius

Bernard Joseph Semeria

James Nolan Hardage

Pradeep Kanapathipillai

Srikanth Balasubramanian

Christopher M Tsay

Daniel U Becker

Preethi Bhargavi Sama

An apparatus includes a memory circuit, and an integrated circuit formed on a single semiconductor substrate and coupled to the memory circuit. The integrated circuit includes a watchdog timer, a plurality of functional circuits coupled together via a communication fabric, and a system management circuit coupled to the watchdog timer and to a subset of the functional circuits via respective dedicated point-to-point interfaces. A given functional circuit may be configured to repeatedly reset the watchdog timer before the watchdog timer expires. The system management circuit may be configured, in response to an expiration of the watchdog timer, to access information in the subset of the functional circuits via the respective point-to-point interfaces. The system management circuit may be further configured to store the accessed information in the memory circuit.

Datalogging circuit triggered by a watchdog timer

Some aspects of this disclosure relate to a peak power manager that includes a first power estimate accumulator circuit configured to receive one or more power estimates associated with one or more subsystems and to generate a first accumulated power estimate. The peak power manage can further include a first-in first-out (FIFO) storage circuit configured to store a plurality of first accumulated power estimates associated with a plurality of clock cycles corresponding to a moving time interval window. The peak power manager can further include a second power estimate accumulator circuit configured to accumulate the plurality of first accumulated power estimates to generate a second accumulated power estimate and a control circuit. The control circuit can be configured to compare the second accumulated power estimate with a threshold power and generate a control signal to control one or more events at the one or more subsystems in response to the second accumulated power estimate satisfying a condition associated with the threshold power.

Peak power management for processing units

Systems, apparatuses, and methods for retaining architected state for relatively frequent switching between sleep and active operating states are described. A processor receives an indication to transition from an active state to a sleep state. The processor stores a copy of a first subset of the architected state information in on-die storage elements capable of retaining storage after power is turned off. The processor supports programmable input/output (PIO) access of particular stored information during the sleep state. When a wakeup event is detected, circuitry within the processor is powered up again. A boot sequence and recovery of architected state from off-chip memory are not performed. Rather than fetch from a memory location pointed to by a reset base address register, the processor instead fetches an instruction from a memory location pointed to by a restored program counter of the retained subset of the architected state information.

Architected state retention for a frequent operating state switching processor

In an embodiment, an integrated circuit may include one or more processors. Each processor may include multiple processor cores, and each core has a different design/implementation and performance level. The processor may support multiple processor states (PStates). Each PState may specify an operating point (e.g. a combination of supply voltage magnitude and clock frequency), and each PState may be mapped to one of the processor cores. During operation, one of the cores is active: the core to which the current PState is mapped. If a new PState is selected and is mapped to a different core, the processor may automatically context switch the processor state to the newly-selected core and may begin execution on that core. The context switch may be performed using a special purpose register (SPR) interconnect. Each processor core in a given processor may be coupled to the SPR interconnect to permit access to the external SPRs.

Hardware migration between dissimilar cores

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Saratoga, CA, United States of America

Richard H Larson