Method and apparatus for on-demand power management

Abstract

A power management apparatus and method are described. The method including monitoring, using a controller, a system bus for a processing demand in a processing system, the processing system comprising the system bus and a system processor, wherein the processing system operates at a first one or more voltages and a first one or more clock frequencies phase-locked to a reference frequency, wherein the controller is a different component than the system processor. The method further including generating a second one or more clock frequencies in response to the processing demand, the second one or more clock frequencies phase-locked to the reference frequency and phase-matched to the first one or more clock frequencies; and switching from the first one or more clock frequencies to the second one or more clock frequencies without halting the processing system.

1 . A method, comprising:
 monitoring, using a controller, a system bus for a processing demand in a processing system, the processing system comprising the system bus and a system processor, wherein the processing system operates at a first one or more voltages and a first one or more clock frequencies phase-locked to a reference frequency, wherein the controller is a different component than the system processor;   generating a second one or more clock frequencies in response to the processing demand, the second one or more clock frequencies phase-locked to the reference frequency and phase-matched to the first one or more clock frequencies; and   switching from the first one or more clock frequencies to the second one or more clock frequencies without halting the processing system.   
     
     
         2 . The method of  claim 1 , wherein monitoring the processing demand comprises:
 detecting a plurality of processing events; and   correlating a clock frequency requirement with the plurality of processing events.   
     
     
         3 . The method of  claim 2 , wherein the plurality of processing events comprises a plurality of commands on the system bus, and wherein correlating the clock frequency requirement with the plurality of processing events comprises recognizing a command pattern. 
     
     
         4 . The method of  claim 1 , wherein generating the second one or more clock frequencies comprises:
 determining values for the second one or more clock frequencies from the processing demand;   scaling the values of the second one or more clock frequencies to compensate for a system temperature and a processing variable;   synthesizing the scaled values of the second one or more clock frequencies; and   stabilizing the second one or more clock frequencies before switching from the first one or more clock frequencies.   
     
     
         5 . The method of  claim 1 , further comprising:
 generating a second one or more voltages in response to the processing demand; and   switching from the first one or more voltages to the second one or more voltages without halting the processing system.   
     
     
         6 . The method of  claim 5 , wherein generating the second one or more voltages comprises:
 determining values for the second one or more voltages from the processing demand;   scaling the values of the second one or more voltages to compensate for a system temperature and a processing variable;   setting the scaled values of the second one or more voltages; and   stabilizing the scaled values of the second one or more voltages before switching from the first one or more voltages.   
     
     
         7 . The method of  claim 5 , wherein the processing variable is a process technology variable. 
     
     
         8 . The method of  claim 5 , wherein the processing variable is a system specific calibration factor. 
     
     
         9 . The method of  claim 5 , wherein switching from the first one or more voltages to the second one or more voltages comprises sequencing the second one or more voltages to reduce a transient power surge. 
     
     
         10 . A processing system, comprising:
 a system bus;   a system processor;   a controller coupled to the system bus to monitor the system bus for a processing demand in the processing system, wherein the processing system operates at a first one or more voltages and a first one or more clock frequencies phase-locked to a reference frequency, wherein the controller is a different component than the system processor;   a clock domain manager coupled to the system processor and the controller to generate a second one or more clock frequencies in response to the processing demand, the second one or more clock frequencies phase-locked to the reference frequency and phase-matched to the first one or more clock frequencies, the clock domain manager configured to switch from the first one or more clock frequencies to the second one or more clock frequencies without halting the processing system.   
     
     
         11 . The processing system of  claim 10 , wherein to monitor the processing demand, the controller is configured to detecting a plurality of processing events, and correlating a clock frequency requirement with the plurality of processing events. 
     
     
         12 . The processing system of  claim 11 , wherein the plurality of processing events comprises a plurality of commands on the system bus, and wherein correlating the clock frequency requirement with the plurality of processing events comprises recognizing a command pattern. 
     
     
         13 . The processing system of  claim 10 , wherein in generating the second one or more clock frequencies, the clock domain manager is configured to:
 determine values for the second one or more clock frequencies from the processing demand;   scale the values of the second one or more clock frequencies to compensate for a system temperature and a processing variable;   synthesize the scaled values of the second one or more clock frequencies; and   stabilize the second one or more clock frequencies before switching from the first one or more clock frequencies.   
     
     
         14 . The processing system of  claim 10 , further comprising a power distribution manager coupled with the controller to generate a second one or more voltages in response to the processing demand, and switch from the first one or more voltages to the second one or more voltages without halting the processing system. 
     
     
         15 . The processing system of  claim 14 , wherein in generating the second one or more voltages, the power distribution manager is configured to:
 determine values for the second one or more voltages from the processing demand;   scale the values of the second one or more voltages to compensate for a system temperature and a processing variable;   set the scaled values of the second one or more voltages; and   stabilize the scaled values of the second one or more voltages before switching from the first one or more voltages.   
     
     
         16 . The processing system of  claim 14 , wherein the processing variable is a process technology variable. 
     
     
         17 . The processing system of  claim 14 , wherein the processing variable is a system specific calibration factor. 
     
     
         18 . The processing system of  claim 14 , wherein switching from the first one or more voltages to the second one or more voltages comprises sequencing the second one or more voltages to reduce a transient power surge.