Device for controlling a multi-core CPU for mobile body, and operating system for the same

• US 20080091974A1
• Filed: 10/09/2007
• Published: 04/17/2008
• Est. Priority Date: 10/11/2006
• Status: Abandoned Application

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nakashima, Yasuo
• Application Number:
  US11/907,107
• Publication Number:
  US 20080091974A1
• Time in Patent Office: Days
• US Class Current: 714/10
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 11/203 using migration
• CPC Class Codes: G06F 11/2043 where the redundant components share a common memory address space
• CPC Class Codes: G06F 11/30 Monitoring
• CPC Class Codes: G06F 2209/5021 Priority
• CPC Class Codes: G06F 9/5044 considering hardware capabilities
• CPC Class Codes: G06F 9/5094 where the allocation takes 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: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

Temperatures of four CPU cores of a multi-core CPU of a mobile body are detected. If the detected temperatures of the CPU cores become high, a clock setting register in a CPU clock-forming unit is set to the highest multiplying factor, and the CPU clock multiplying factors of the other clock setting registers are lowered. The clock frequencies of the CPU cores are lowered except a specified CPU core of a highest priority while maintaining the highest operation clock frequency for the specified CPU core, to thereby lower the temperature of the multi-core CPU. Alternatively, when the specified CPU core becomes abnormal, the processing assigned to it is reassigned to another CPU core of the plurality of CPU cores.

Claims

1. A device for a mobile body comprising:

a multi-core CPU including a plurality of CPU cores to which different processing are assigned, respectively;

abnormal condition detection means for detecting an abnormal condition that lowers processing capability of the multi-core CPU;

priority storage means for storing priority degrees of the respective processing assigned to the plurality of CPU cores;

capability adjusting means for adjusting processing capabilities of the plurality of CPU cores; and

control means which, when the abnormal condition is detected, controls the capability adjusting means to lower the processing capabilities of the CPU cores depending upon the priority degrees except that of a specified CPU core among the plurality of CPU cores, the specified CPU core being assigned a highest degree of priority in the priority storage means.

2. The device according to claim 1, wherein the capability adjusting means adjusts all of the processing capabilities of the CPU cores except the specified CPU core.

3. The device according to claim 1, wherein:

the abnormal condition detection means detects at least any one of the temperatures of the plurality of CPU cores that has exceeded a predetermined value as abnormal condition that lowers the processing capability of the multi-core CPU for the mobile body; and

the capability adjusting means lowers operation clock frequencies of the CPU cores except that of the specified CPU core.

4. The device according to claim 3, wherein:

the control means controls the capability adjusting means to lower both operation clock frequencies of the specified CPU core and other CPU cores as the temperature of the plurality of CPU cores rises; and

a temperature for lowering the operation clock frequency of the specified CPU core from a highest frequency is higher than a temperature for lowering the operation clock frequency of the other CPU cores from the highest frequency.

5. The device according to claim 3, wherein:

the control means controls the capability adjusting means to stop operations of the other CPU cores and maintain an operation of the specified CPU core at a predetermined highest temperature.

6. The device according to claim 1, wherein:

the specified CPU core executes processing of assisting a vehicle drive; and

the CPU cores other than the specified CPU core execute other processing which are not related to the assisting of a vehicle drive.

8. The operating system according to claim 6, wherein, when the abnormal condition detection processing detects that all of the plurality of CPU cores are abnormal, the reassigning processing executes processing necessary for ending all of the processing assigned to the plurality of the CPU cores and thereafter stops all of the processing of the plurality of the CPU cores.

9. A program medium for having a computer for a mobile body equipped with a multi-core CPU execute a function of the operating system of claim 6.

10. A device for assisting an operation of a mobile body equipped with the operating system for a multi-core CPU for a mobile body of claim 6.

7. An operating system for a multi-core CPU for a mobile body including a plurality of CPU cores to which different processing are assigned, respectively, the operating system comprising:

abnormal condition detection processing for detecting an abnormal condition that indicates incapability of assigned processing in any one of the plurality of CPU cores; and

reassigning processing which, when the abnormal condition is detected, reassigns the processing that has been assigned to an abnormal one of the plurality of CPU cores to a normal one of the plurality of CPU cores other than the abnormal one depending upon a predetermined order of priorities.