BACKWARD COMPATIBILITY THROUGH USE OF SPOOF CLOCK AND FINE GRAIN FREQUENCY CONTROL

摘要

An application runs at a first operating frequency if the application is designed for a current version of a system and runs at a second operating frequency if the application is designed for a prior version of the system that operates at a lower frequency than the first operating frequency. The second operating frequency may be higher than the operating frequency of the prior version of the system to account for differences in latency, throughput or other processing characteristics between the two systems. Software readable cycle counters are based on a spoof clock running at the operating frequency of the prior version of the system, rather than the true operating frequency. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

主权项

1. A method, comprising:
a) determining whether an application loaded on a current version of a system is for the current version of a system or a less powerful version of the system, wherein the current version of the system is characterized by a standard operating frequency; b) miming the application on a processor at the standard operating frequency of the current version of the system when the application is designed for a current version of a system; or c) miming the application at a second operating frequency when the application is designed for a less powerful version of the system, wherein the less powerful version of the system is characterized by a different standard operating frequency, wherein the second operating frequency is less than the standard operating frequency of the current version of the system and higher than the standard operating frequency of the less powerful version of the system.