Electronic control unit, in particular for a device provided in a motor vehicle

• US 6,308,121 B1
• Filed: 09/23/1997
• Issued: 10/23/2001
• Est. Priority Date: 09/23/1996
• Status: Expired due to Fees

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Ulm, Michael
• Primary Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US08/935,622
• Time in Patent Office: 1,491 Days
• Field of Search: 701/29, 701/33, 701/102, 701/35, 701/114, 701/115, 340/438, 340/439, 340/436, 340/945, 340/959, 340/588, 123/479, 731/174, 731/16
• US Class Current: 701/35
• CPC Class Codes: G06F 11/00 Error detection; Error correction; Monitoring error detection, correction or monitoring in information storage based on relative movement between record carrier and transducer G11B20/18; monitoring, i.e. supervising the progress of recording or reproducing G11B27/36; in static stores G11C29/00
• CPC Class Codes: G06F 11/004 Error avoidance G06F11/07 and subgroups take precedence
• CPC Class Codes: G06F 11/0754 by exceeding limits
• CPC Class Codes: G06F 2201/81 Threshold
• CPC Class Codes: G11C 29/74 using duplex memories, i.e. using dual copies

Abstract

A control unit, in particular for a device provided in a motor vehicle, has a computer, a first volatile data memory and a second nonvolatile data memory connected to a temperature sensor. During operation, variable data are transmitted from the first to the second data memory. Information regarding the temperature of the nonvolatile data memory is supplied by the temperature sensor to the computer. Data from the volatile data memory are copied to the nonvolatile data memory only when the temperature that has been signaled falls below a predetermined value. Data are read from the nonvolatile data memory up to an upper temperature limit which lies above the predetermined value.

Claims

1. An electronic control unit, comprising:

a first volatile data memory;

a second nonvolatile data memory for receiving and storing variable data from said volatile data memory;

a temperature sensor supplying information signaling a temperature of said nonvolatile data memory; and

a computer receiving the temperature information from said temperature sensor, said computer copying data from said volatile data memory to said nonvolatile data memory only when the temperature signaled by said temperature sensor falls below a predetermined value, and data being read from said nonvolatile data memory up to an upper temperature limit lying above said predetermined value.

2. The control unit according to claim 1, wherein data are copied cyclically from said volatile data memory to said nonvolatile data memory during normal operation of the control unit.

3. The control unit according to claim 1, including a switch to be opened by a user of the electronic control unit for enabling said computer to copy data from said volatile data memory to said nonvolatile data memory.

4. The control unit according to claim 3, wherein said switch is subsequently closed for suppressing copying of values back from said nonvolatile data memory to said volatile data memory.

5. The control unit according to claim 1, including a supply voltage source, said volatile data memory having an operating voltage input connected to said supply voltage source, and a switch opened by said computer after copying has taken place or if a signal of said temperature sensor has exceeded said predetermined value.

6. The control unit according to claim 1, wherein said predetermined value corresponds to a maximum permissible erasure and writing temperature for said nonvolatile data memory.

7. The control unit according to claim 1, including:

an internal operating voltage supply;

an operating voltage input of said volatile data memory connected to said operating voltage supply;

a supply voltage source for said computer; and

a switch connected to said computer and to said supply voltage source for internally disconnecting said supply voltage source with a command from said computer;

said computer opening said switch after the temperature signaled by said temperature sensor has fallen below said predetermined value and after the data have been copied from said volatile data memory to said nonvolatile data memory.

8. The control unit according to claim 7, wherein said supply voltage source also supplies said volatile data memory and said nonvolatile data memory, and said switch internally disconnects said supply voltage source from said volatile data memory and said nonvolatile data memory with a command from said computer.

9. A motor vehicle device having an electronic control unit, comprising:

a volatile data memory;

a nonvolatile data memory for receiving and storing variable data from said volatile data memory;

a temperature sensor supplying information signaling a temperature of said nonvolatile data memory; and

a computer receiving the temperature information from said temperature sensor, said computer copying data from said volatile data memory to said nonvolatile data memory only when the temperature signaled by said temperature sensor falls below a predetermined value, and data being read from said nonvolatile data memory up to an upper temperature limit lying above said predetermined value.