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Copyright © 2004, Intel CorporationEnhanced Intel® SpeedStep® Technology for the Intel® Pentium® M Processor White Paper 3 Contents 1.0 Introduction ......................................................................................................................................4 2.0 Processor Support...........................................................................................................................4 3.0 Thermal Design Power.....................................................................................................................5 4.0 Implementation.................................................................................................................................6 5.0 Software Considerations.................................................................................................................7 6.0 ACPI Considerations......................................................................................................................10 7.0 Non-ACPI Implementations...........................................................................................................11 8.0 Voltage Regulator Support............................................................................................................12 9.0 Conclusion......................................................................................................................................12Enhanced Intel® SpeedStep® Technology for the Intel® Pentium® M Processor 4 White Paper 1.0 Introduction Enhanced Intel® SpeedStep® Technology has revolutionized thermal and power management by giving application software greater control over the processor’s operating frequency and input voltage. Systems can easily manage power consumption dynamically. This paper describes how this flexible power management scheme is implemented and how designers can best integrate this technology into their current or next-generation board design. Today’s embedded systems are demanding greater performance at equivalent levels of power consumption. Legacy hardware support for backplanes, board sizes and thermal solutions have forced design teams to place greater emphasis on power and thermal budgets. Intel has extended architectural innovation for saving power by implementing new features such as Enhanced Intel SpeedStep Technology. Enhanced Intel SpeedStep Technology allows the processor performance and power consumption levels to be modified while a system is functioning. This is accomplished via application software, which changes the bus-to-core frequency ratio and the processor core voltage (Vcc). A variety of inputs such as system power source, processor thermal state, or operating system policy are used to determine the proper operating state. The software model behind Enhanced Intel SpeedStep Technology has ultimate control over the frequency and voltage transitions. This software model is a major step forward over previous implementations of Intel SpeedStep technology. Legacy