Operating vehicular processor-based systems

• US 6,249,739 B1
• Filed: 08/31/1999
• Issued: 06/19/2001
• Est. Priority Date: 08/31/1999
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Noehring, Lee P., Fleming, Bruce L.
• Primary Examiner(s): Dolinar, Andrew M.
• Assistant Examiner(s): Vo, Hieu T
• Application Number:
  US09/387,349
• Time in Patent Office: 658 Days
• Field of Search: 701/113, 701/102, 701/101, 701/115, 701/114, 710/100, 710/101, 710/260, 713/323, 123/179.16, 123/179.21, 123/179.3
• US Class Current: 701/113
• CPC Class Codes: G06F 1/305 in the event of power-supply fluctuations
• CPC Class Codes: G06F 11/1441 Resetting or repowering

Abstract

A processor-based system in a vehicle may be quickly suspended to a lower power consumption state after detecting a signal indicative of engine cranking. Advantageously, the system may be caused to enter the lower power consumption state prior to the time that power is reduced as a result of engine cranking. If the operating system is active when the signal is detected, a routine may be called which causes device contexts to be saved before returning the system to a reduced power consumption state. Otherwise, if the operating system is inactive, an interrupt handler may be called which immediately returns the system to a reduced power consumption state. In this way, the system may be reliably restored to a lower power consumption state before being exposed to the power reduction inherent in engine cranking.

Claims

1. A processor-based system for use in a vehicle comprising:

a processor;

a storage coupled to said processor;

a detector to detect a signal indicative of engine cranking and to suspend a processing function of said system to a lower power consumption state before a crank induced power reduction occurs.

2. The system of claim 1 wherein said processor-based system suspends to a reduced power consumption state within 20 milliseconds after detecting the signal indicative of engine cranking.

3. The system of claim 2 wherein said processor is programmed to act as said detector.

4. The system of claim 3 including a basic input/output system, coupled to said processor, an operating system and an interrupt handler or return the system to a lower power consumption state when the operating system is inactive when the signal indicative of engine cranking signal is detected.

5. An article comprising a medium for storing instructions that cause a processor-based system in a vehicle to:

detect a signal indicative of engine cranking; and

suspend a processing function of the system to a lower power consumption state before a crank induced power reduction occurs.

6. The article of claim 5 further storing instructions that cause a processor-based system to determine whether the operating system of said processor-based system is active after detecting a signal indicative of engine cranking.

7. The article of claim 6 further storing instructions that cause a processor-based system to use a first interrupt handler if an operating system is active and use a second interrupt handler if the operating system is inactive.

8. The article of claim 7 further storing instructions that cause a processor-based system to install a first vector to the first interrupt handler after system reset and replace said first vector with a second vector to the second interrupt handler after the operating system becomes active.

9. The article of claim 8 further storing instructions that cause a processor-based system to save device contexts before causing the system to enter the lower power consumption state if the operating system is active.

10. The article of claim 9 further storing instructions that cause a processor-based system to call a routine for saving the device contexts directly without involving the operating system upon detecting a signal indicative of engine cranking.

11. The article of claim 8 further storing instructions that cause a processor-based system to return the system to a lower power consumption state if the operating system is not active.

12. A method for operating a processor-based system in a vehicle comprising:

detecting a signal indicative of engine cranking; and

suspending a processing function of said system to a lower power consumption state before a crank induced power reduction occurs.

13. The method of claim 12 further including determining whether the operating system of the processor-based system in a vehicle is active after detecting a signal indicative of engine cranking.

14. The method of claim 13 further including using a first interrupt handler if an operating system is active and using a second interrupt handler if the operating system is inactive.

15. The method of claim 14 further including installing a first vector to the first interrupt handler after system reset and replacing said first vector with a second vector to the second interrupt handler after the operating system becomes active.

16. The method of claim 15 wherein, if the operating system is active, saving device contexts before causing said system to enter the lower power consumption state.

17. The method of claim 16 further including calling a routine for saving the device contexts directly without involving the operating system, upon detecting a signal indicative of engine cranking.

18. The method of claim 15 further including immediately returning the system to a lower power consumption state if the operating system is not active.

19. The method of claim 12 wherein suspending includes causing said system to enter a lower power consumption state within 20 milliseconds after detecting a signal indicative of engine cranking.

20. The method of claim 12 wherein suspending includes determining the lower power consumption state that the system was in at the time a signal indicative of engine cranking was detected and suspending said system to that state.