Electronic apparatus and storage medium storing load distribution program

• US 8,548,393 B2
• Filed: 09/17/2009
• Issued: 10/01/2013
• Est. Priority Date: 03/23/2007
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Kokubo, Asao
• Primary Examiner(s): West, Lewis
• Assistant Examiner(s): Chan, Richard
• Application Number:
  US12/585,567
• Publication Number:
  US 20100009726A1
• Time in Patent Office: 1,475 Days
• Field of Search: 455/558, 455/557, 370/463, 711/122
• US Class Current: 455/84
• CPC Class Codes: G06F 1/324 by lowering clock frequency
• CPC Class Codes: G06F 2209/5017 Task decomposition
• CPC Class Codes: G06F 9/4893 taking into account power or heat criteria power management in computers in general G06F1/3203; thermal management in computers in general G06F1/206
• CPC Class Codes: G06F 9/505 considering the load
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

An electronic apparatus includes: a clock generation section which generates and outputs a clock of a frequency according to a state; and an MPU and a DSP which, being supplied with the clock generated by the clock generation section, execute processes at a processing speed synchronized with the clock. The electronic apparatus further includes: a load prediction section which predicts a DSP load based on a DSP application to be executed now out of DSP applications installed by being coded for processing by the DSP as well as on a frequency of a clock currently being outputted from the clock generation section; and a load allocation section which allocates part of processes of the DSP application to be executed now to the MPU, based on the load predicted by the load prediction section and thereby makes the MPU execute the part of processes.

Claims

1. An electronic apparatus comprising:

a clock generation section which generates and outputs a clock of a frequency according to a state;

an MPU and a DSP which, being supplied with the clock generated by the clock generation section, execute processes at a processing speed synchronized with the clock;

a load prediction section which predicts a DSP load based on a DSP application to be executed now out of DSP applications installed by being coded for processing by the DSP as well as on a frequency of a clock currently being outputted from the clock generation section;

a load allocation section which allocates a part of processes of the DSP application to be executed now to the MPU, based on the load predicted by the load prediction section and thereby makes the MPU execute the part of processes; and

an emulator which makes the MPU execute DSP applications, wherein the MPU executes a part of the DSP applications using the emulator, the part of the DSP applications being allocated by the load allocation section.

2. The electronic apparatus according to claim 1, wherein:

the electronic apparatus is a mobile telephone which has three states, namely, an idle state, a standby state, and an engaged state, the idle state including an activated state that occurs upon power-on and a suspended state that occurs upon power-down; and

the clock generation section generates and outputs a clock of a relatively low frequency and a clock of a relatively high frequency in the standby state and the engaged state, respectively.

3. The electronic apparatus according to claim 1, wherein:

each of the DSP applications includes one or more processes;

a load table is provided, defining a load for each of the processes of the DSP application; and

the load prediction section predicts the DSP load based on the load table and the frequency of the clock currently being outputted from the clock generation section.

4. The electronic apparatus according to claim 3, further comprising:

a substate management section which manages a current substate out of a plurality of substates into which a state in which the frequency of the clock outputted from the clock generation section remains constant is further divided according to loads; and

a load threshold table which defines for each of the plurality of substates, a load threshold used to determine whether to allocate the processes of the DSP application to the MPU,

wherein the load allocation section determines processes which are to be allocated to the MPU, based on the load predicted by the load prediction section, the current substate, and the load threshold table.

5. The electronic apparatus according to claim 4, wherein the load threshold table defines a load threshold for each unit of processes by treating a plurality of corresponding processes in a plurality of DSP applications as a unit when the plurality of DSP applications are viewed in a cross-sectional manner across the plurality of DSP applications.

6. A storage medium that stores a load distribution program which causes, when executed on an electronic apparatus, the electronic apparatus to operate as an electronic apparatus comprising:

a clock generation section which generates and outputs a clock of a frequency according to a state;

an MPU and a DSP which, being supplied with the clock generated by the clock generation section, execute processes at a processing speed synchronized with the clock;

a load prediction section which predicts a DSP load based on a DSP application to be executed now out of DSP applications installed by being coded for processing by the DSP as well as on a frequency of a clock currently being outputted from the clock generation section;

a load allocation section which allocates a part of processes of the DSP application to be executed now to the MPU, based on the load predicted by the load prediction section and thereby makes the MPU execute the part of processes; and

an emulator which makes the MPU execute DSP applications, wherein the MPU executes a part of the DSP applications using the emulator, the part of the DSP applications being allocated by the load allocation section and converted by the emulator.

7. The storage medium according to claim 6, wherein:

each of the DSP applications includes one or more processes;

a load table is provided, defining a load for each of the processes of the DSP application; and

the load prediction section predicts the DSP load based on the load table and the frequency of the clock currently being outputted from the clock generation section.

8. The storage medium according to claim 7,

wherein the electronic apparatus further comprises:

a substate management section which manages a current substate out of a plurality of substates into which a state in which the frequency of the clock outputted from the clock generation section remains constant is further divided according to loads; and

a load threshold table which defines for each of the plurality of substates, a load threshold used to determine whether to allocate the processes of the DSP application to the MPU, and

the load allocation section determines processes which are to be allocated to the MPU, based on the load predicted by the load prediction section, the current substate, and the load threshold table.