Abstract: Techniques and mechanisms to manage power states for a system-on-chip (SOC). Multiple modules of the SOC include a first module to perform a task including one or more accesses to a memory. In an embodiment, the SOC is transitioned to one of a path-to-memory-available (PMA) power state and a path-to-memory-not-available (PMNA) power state, where the transition is in response to an indication that, of the multiple modules, only the first module is to access the memory during the task. The PMA power state enables data communication between the memory and the first module and prevents data communication between the memory and any other module of the multiple modules. In another embodiment, the PMNA power state prevents data communication between the memory and any of the multiple modules, but allows a low latency transition from the PMNA power state to the PMA power state.

Abstract: A lock detector circuit for detecting a lock condition between a reference signal and a feedback signal includes a first counter for outputting a first counter value indicative of a number of clock cycles of the reference signal, and a second counter for outputting a second counter value indicative of a number of clock cycles of the feedback signal. An asynchronous comparator receives the first and second counter values and provides an output signal having a pulse width that is proportional to the difference between the first and second counter values. A pulse width detector receives the comparator output signal and produces an output signal that is indicative of the relationship between the pulse width of the comparator output signal and a predetermined threshold value. A state machine controls the state of at least one lock indication signal according to the pulse width detector output signal.

Abstract: A lock detector circuit for detecting a lock condition between a reference signal and a feedback signal includes a first counter for outputting a first counter value indicative of a number of clock cycles of the reference signal, and a second counter for outputting a second counter value indicative of a number of clock cycles of the feedback signal. An asynchronous comparator receives the first and second counter values and provides an output signal having a pulse width that is proportional to the difference between the first and second counter values. A pulse width detector receives the comparator output signal and produces an output signal that is indicative of the relationship between the pulse width of the comparator output signal and a predetermined threshold value. A state machine controls the state of at least one lock indication signal according to the pulse width detector output signal.