Method for storing data in memory

• US 5,909,391 A
• Filed: 06/26/1997
• Issued: 06/01/1999
• Est. Priority Date: 06/26/1996
• Status: Expired due to Term

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Loibl, Josef
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): Lam, David
• Application Number:
  US08/883,032
• Time in Patent Office: 705 Days
• Field of Search: 365/185.08, 365/185.14, 365/63, 126/21, 172/2
• US Class Current: 365/185.08
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: G06F 11/076 by exceeding a count or rate limit, e.g. word- or bit count limit
• CPC Class Codes: G06F 11/0763 by bit configuration check, e.g. of formats or tags
• CPC Class Codes: G06F 11/0796 Safety measures, i.e. ensuring safe condition in the event of error, e.g. for controlling element
• CPC Class Codes: G06F 11/08 Error detection or correction by redundancy in data representation, e.g. by using checking codes

Abstract

A method for storing data in memory, in particular adaptation data, includes reading the data out of a first, volatile memory and storing the data in a second, nonvolatile memory. The frequency with which data are stored in the second memory, in particular an EEPROM, is reduced by providing that the data are written in alternation into at least two different memory regions. Moreover, a storage operation of the data occurs only at predetermined time intervals and at a speed of the motor vehicle that is below a predeterminable limit speed. Preferably, a storage operation is performed only when the temperature of the second memory is below a limit temperature.

Claims

1. A method for storing data in memory, which comprises:

reading the data out of first, volatile memory; and

storing the data in a second, nonvolatile memory only if a vehicle in which the second memory is located is moving more slowly than a predeterminable speed.

2. The method according to claim 1, which comprises storing the data in alternation in a first memory region and in at least one second memory region of the second, nonvolatile memory.

3. The method according to claim 1, which comprises storing the data in cyclical order in the second memory.

4. The method according to claim 2, which comprises storing the data in the memory region which has not been written into for the longest time and thus has the oldest data.

5. The method according to claim 2, which comprises storing backup data in alternation with the data in the first or second memory region of the second memory, upon each storage operation for the data.

6. The method according to claim 2, which comprises incrementing a counter of the memory region in which the data has been stored to a value representing a highest value of a counter of the memory regions.

7. The method according to claim 2, which comprises:

initializing a control unit by searching for the memory region of the second memory in which data have most recently been written and in which a check of backup data indicates a correct storage operation;

writing the data of the memory region into the first memory; and

using the data written into the first memory by the control unit for executing a control process.

8. The method according to claim 7, which comprises using a memory region having an invalid plausibility detector for the storage operation.

9. The method according to claim 7, which comprises writing the data into a memory region into which no data has been written for the longest time and which thus has the oldest adaptation data for the storage operation, if no memory region with an invalid plausibility detector is present.

10. The method according to claim 1, which comprises storing the data only after a predeterminable length of time has elapsed since the last storage operation.

11. The method according to claim 10, which comprises performing a storage operation only whenever a speed at which the second memory is moved is below a predeterminable limit speed.

12. The method according to claim 10, which comprises permitting a storage operation only if a temperature of the second memory is below a predeterminable limit temperature.