Automatically determining operating parameters of a power management device

Abstract

Automatically determining operating parameters of a power management device is described.

1 . A computer-implemented method, comprising:
 providing a power management device to control power provided to a peripheral device, coupled to a host device, according to a plurality of operating states of the power management device; and   automatically determining, by auto-tuning logic, an operating parameter for at least one of the operating states of the power management device.   
     
     
         2 . The method of  claim 1 , wherein automatically determining the operating parameter comprises determining the operating parameter for the at least one of the operating states of the power management device without a user manually setting the operating parameter. 
     
     
         3 . The method of  claim 1 , wherein the operating parameter is an optimal current threshold for current sensing by the power management device in the at least one operating state, and wherein the optimal current threshold is the highest current level expected to be drawn from the power management device in the at least one operating state. 
     
     
         4 . The method of  claim 1 , wherein the operating parameter is an optimal operating voltage for the at least one operating state, and wherein the optimal operating voltage is the lowest possible voltage provided to the peripheral device in the at least one operating state that does not cause the peripheral device to stop operating. 
     
     
         5 . The method of  claim 1 , wherein said automatically determining the optimal operating voltage comprises:
 transitioning the power management device to operate in a first of the plurality of operating states;   lowering a first operating voltage provided to the peripheral device in the first operating state to detect at what voltage level the peripheral device stops operating; and   setting the optimal operating voltage of the first operating state based on the voltage level at which the peripheral device stops operating.   
     
     
         6 . The method of  claim 5 , wherein said lowering the first operating voltage comprises incrementally lowering the first operating voltage according to a unit step size, and wherein said setting comprises increasing the first operating voltage by a minimal safe margin from the voltage level at which the peripheral device stops operating to be set as the optimal operating voltage of the first operating state. 
     
     
         7 . The method of  claim 5 , wherein said lowering the first operating voltage comprises incrementally lowering the first operating voltage according to a unit step size, and wherein said setting comprises setting the optimal operating voltage to be the voltage level of the increment before the voltage level at which the peripheral device stops operating. 
     
     
         8 . The method of  claim 5 , further comprising determining an optimal current threshold for the optimal operating voltage of the first operating state, wherein the optimal current threshold is the highest current level expected to be drawn from the power management device in the first operating state. 
     
     
         9 . The method of  claim 8 , wherein the first operating state corresponds to the highest power mode of the peripheral device, and wherein the method further comprises:
 transitioning the power management device to operate in a second of the plurality of operating states, wherein the second operating state corresponds to a lower power mode than the highest power mode of the peripheral device;   determining the optimal current threshold for the second operating state, wherein the optimal current threshold for the second operating state is the highest current level expected to be drawn from the power management device in the second operating state; and   determining the optimal operating voltage for the second operating state, wherein the optimal operating voltage for the second operating state is the lowest possible voltage provided to the peripheral device in the second operating state that does not cause the peripheral device to stop operating.   
     
     
         10 . The method of  claim 9 , wherein determining the optimal operating voltage for the second operating state comprises:
 lowering a second operating voltage provided to the peripheral device in the second operating state to detect at what voltage level the peripheral device stops operating; and   setting the optimal operating voltage of the second operating state based on the voltage level at which the peripheral device stops operating.   
     
     
         11 . The method of  claim 10 , further comprising determining an optimal current threshold for the optimal operating voltage of the second operating state, wherein the optimal current threshold for optimal operating voltage is the highest current level expected to be drawn from the power management device in the second operating state while the peripheral device operates at the optimal operating voltage. 
     
     
         12 . The method of  claim 1 , wherein said automatically determining comprises determining optimal timing for transitioning between at least two of the plurality of operating states of the power management device. 
     
     
         13 . The method of  claim 1 , wherein said automatically determining comprises determining optimal clock frequency the at least one of the plurality of operating states of the power management device. 
     
     
         14 . A computer-implemented method of auto-tuning optimal operating parameters of a power management device coupled to a host device and a peripheral device, comprising:
 placing the power management device in a learning mode;   performing a plurality of operations between the host device and the peripheral device during the learning mode; and   automatically determining, by auto-tuning logic, a plurality of optimal operating parameters for a plurality of operating states of the power management device based the plurality of operations.   
     
     
         15 . The method of  claim 14 , further comprising programming the power management device to operate according to the plurality of optimal operating parameters when in a normal operating mode. 
     
     
         16 . The method of  claim 14 , wherein the method is performed at power-up of the host device. 
     
     
         17 . The method of  claim 14 , wherein the method is performed periodically during operation of the host device. 
     
     
         18 . An apparatus, comprising:
 auto-tuning logic to place a power management device in a learning mode, wherein the power management device provides power to a peripheral device according to an operating state of the power management device; and   processing logic to perform a plurality of operations between a host device and the peripheral device during the learning mode, wherein the auto-tuning logic is configured to automatically determine an operating parameter for the operating state.   
     
     
         19 . The apparatus of  claim 18 , wherein the auto-tuning logic is configured to determine the operating parameter without a user manually setting the operating parameter. 
     
     
         20 . The apparatus of  claim 18 , wherein the auto-tuning logic resides in the host device. 
     
     
         21 . The apparatus of  claim 18 , wherein the auto-tuning logic resides in the power management device. 
     
     
         22 . The apparatus of  claim 18 , wherein the auto-tuning logic is configured to program the power management device to operate according to the operating parameter when in a normal operating mode. 
     
     
         23 . The apparatus of  claim 18 , wherein the operating parameter is at least one of an optimal operating voltage for the operating state and an optimal current threshold for current sensing by the power management device, wherein the optimal operating voltage is the lowest possible voltage provided to the peripheral device in the operating state that does not cause the peripheral device to stop operating, and wherein the optimal current threshold is the highest current level expected to be drawn from the power management device in the operating state. 
     
     
         24 . The apparatus of  claim 18 , wherein the power management device comprises:
 an adjustable voltage regulator to provide power to the peripheral device; and   a current sensing circuit to sense the current provided to the peripheral device during the learning mode.   
     
     
         25 . The apparatus of  claim 24 , wherein the operating parameter is an optimal current threshold for current sensing by the current sensing circuit, wherein the optimal current threshold is the highest current level expected to be drawn from the power management device in the operating state, and wherein the auto-tuning logic comprises current threshold tuning logic to determine the optimal current threshold based on the sensed current provided to the peripheral device. 
     
     
         26 . The apparatus of  claim 25 , wherein the power management device further comprises a comparator to compare the sensed current provided to the peripheral device and a set current corresponding to a current set point of the current threshold and to provide an output to the current threshold tuning logic to indicate whether the current set point should be increased or set as the optimal current threshold. 
     
     
         27 . The apparatus of  claim 26 , further comprising:
 a current threshold register to store the optimal current threshold;   a status register to indicate when the current threshold tuning logic has set the optimal current threshold in the current threshold register; and   a configuration register to indicate when the current threshold tuning logic is enabled.   
     
     
         28 . The apparatus of  claim 18 , wherein the operating parameter is an optimal operating voltage for the operating state, wherein the optimal operating voltage is the lowest possible voltage provided to the peripheral device in the operating state that does not cause the peripheral device to stop operating, and wherein the auto-tuning logic comprises voltage tuning logic to determine the optimal operating voltage for the operating state of the power management device. 
     
     
         29 . The apparatus of  claim 28 , wherein the power management device comprises:
 an adjustable voltage regulator to provide an operating voltage to the peripheral device; and   a power controller coupled to the adjustable voltage regulator, wherein the power controller is configured to receive a control signal from the voltage tuning logic to lower the operating voltage provided to the peripheral device, and wherein the voltage tuning logic is configured to detect at what voltage level the peripheral device stops operating and to set the optimal operating voltage based on the voltage level at which the peripheral device stops operating.   
     
     
         30 . The apparatus of  claim 18 , wherein the plurality of optimal operating parameters comprises optimal timing for transitioning between at least two of the plurality of operating states of the power management device. 
     
     
         31 . The apparatus of  claim 18 , wherein the plurality of optimal operating parameters comprises an optimal clock frequency for each of the plurality of the plurality of operating states of the power management device. 
     
     
         32 . A computer readable storage medium that provides instructions, which when executed on a processing device, cause the processing device to perform a method comprising:
 placing a power management device in a learning mode, wherein the power management device provides power to a peripheral device according to an operating state of the power management device;   performing a plurality of operations between the processing device and the peripheral device during the learning mode; and   automatically determining a plurality of optimal operating parameters for the operating state of the power management device based on the plurality of operations.   
     
     
         33 . The computer readable storage medium of  claim 32 , wherein the method further comprises programming the power management device to operate according to the plurality of optimal operating parameters when in a normal operating mode. 
     
     
         34 . The computer readable storage medium of  claim 32 , wherein the plurality of optimal operating parameters comprise an optimal current threshold for current sensing by the power management device in each of the plurality of operating states and an optimal operating voltage for each of the plurality of operating states, wherein the optimal current threshold is the highest current level expected to be drawn from the power management device in the corresponding operating state, wherein the optimal operating voltage is the lowest possible voltage provided to the peripheral device in the corresponding operating state that does not cause the peripheral device to stop operating, and wherein said automatically determining the plurality of optimal operating parameters comprises:
 for each of a plurality of operating states of the power management device:
 determining a first optimal current threshold for a current operating voltage provided to the peripheral device in the corresponding operating state; 
 lowering the current operating voltage provided to the peripheral device in the corresponding operating state to detect at what voltage level the peripheral device stops operating; 
 setting the optimal operating voltage of the first operating state based on the voltage level at which the peripheral device stops operating; and 
 determining a second optimal current threshold for the optimal operating voltage, wherein the plurality of optimal operating parameters comprises the optimal operating voltage and the second optimal current threshold. 
   
     
     
         35 . The computer readable storage medium of  claim 34 , wherein determining the first optimal current threshold and the second optimal current threshold each comprises:
 setting a current set point to a default value;   performing one or more operations between the host device and the peripheral device to operate the peripheral device in its highest current draw mode that is expected during the corresponding operating state;   measuring the current provided to the peripheral device while performing the one or more operations;   comparing the current and a set current corresponding to the current set point;   if the current provided to the peripheral device is higher than the set current:
 increasing the current set point to a higher value than the default value; and 
 comparing the current provided to the peripheral device and a set current corresponding to the increased current set point; and 
   if the current provided to the peripheral device is not higher than the set current, setting the current set point as the optimal current threshold.