Efficient use of CRC with limited data

• US 8,694,879 B1
• Filed: 09/14/2011
• Issued: 04/08/2014
• Est. Priority Date: 09/14/2010
• Status: Expired due to Fees

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Inventors: Czarnocki, Walter, Peichl, Thomas, Joseph, Kyle
• Primary Examiner(s): Abraham, Esaw
• Application Number:
  US13/232,252
• Time in Patent Office: 937 Days
• Field of Search: 714/758, 714/781, 714/807
• US Class Current: 714/807
• CPC Class Codes: G01D 18/00 Testing or calibrating apparatus or arrangements provided for in groups G01D1/00 - G01D15/00
• CPC Class Codes: H03M 13/09 Error detection only, e.g. using cyclic redundancy check [CRC] codes or single parity bit
• CPC Class Codes: H04L 1/0061 Error detection codes

Abstract

An automotive sensor reads from memory previously stored back-calculated diagnostic-code values for which a fixed cyclic-redundancy-check (“CRC”) value is valid and transmits the previously stored back-calculated diagnostic-code values read from memory each paired together with the fixed CRC value.

Claims

1. A method performed by an automotive sensor, the method comprising:

reading from memory previously stored back-calculated diagnostic-code values for which a fixed cyclic-redundancy-check (“

CRC”

) value is valid;

transmitting the previously stored back-calculated diagnostic-code values read from memory each paired together with the fixed CRC value; and

wherein the previously stored back-calculated diagnostic-code values for which the fixed-CRC value is valid include values within a range of 800-FFF hexadecimal, the fixed-CRC value is 1B hexadecimal, and a diagnostic-error-codes-message identifier is 01 hexadecimal.

2. The method of claim 1, wherein the fixed-CRC value corresponds to a diagnostic-code value that indicates a no-error condition.

3. The method of claim 1, wherein the previously stored back-calculated diagnostic-code values for which the fixed-CRC value is valid are selected from the group of hexadecimal values consisting of:

83E, 867, 88C, 8D5, 903, 95A, 9B1, 9E8, AM, A44, AAF, AF6, B20, B79, B92, BCB, C21, C78, C93, CCA, D1C, D45, DAE, DF7, E02, ESB, EB0, EE9, F3F, F66, F8D, and FD4.

4. The method of claim 3, using a Single-Edge-Nibble-Transmission-for-Automotive-Applications (“

SENT”

)-Standard-defined diagnostic-code value of 000 hexadecimal to indicate a no-error condition.

5. Apparatus comprising:

a memory having stored therein back-calculated diagnostic-code values for which a fixed cyclic-redundancy-check (“

CRC”

) value is valid;

an automotive sensor configured to transmit the back-calculated diagnostic-code values each paired together with the fixed-CRC value; and

the apparatus of claim wherein the previously stored back-calculated diagnostic-code values for which the fixed-CRC value is valid include values within a range of 800-FFF hexadecimal the fixed-CRC value is 1LB hexadecimal, and a diagnostic-error-codes-message identifier is 01 hexadecimal.

6. The apparatus of claim 5, wherein the fixed-CRC value corresponds to a diagnostic-code value that indicates a no-error condition.

7. The apparatus of claim 5, wherein the previously stored back-calculated diagnostic-code values for which the fixed-CRC value is valid are selected from the group of hexadecimal values consisting of:

83E, 867, 88C, 8D5, 903, 95A, 9B1, 9E8, AM, A44, AAF, AF6, B20, B79, B92, BCB, C21, C78, C93, CCA, D1C, D45, DAE, DF7, E02, ESB, EB0, EE9, F3F, F66, F8D, and FD4.

8. The apparatus of claim 7, wherein a Single-Edge-Nibble-Transmission-for-Automotive-Applications (“

SENT”

)-Standard-defined-diagnostic-code value of 000 hexadecimal is used to indicate a no-error condition.

9. The apparatus of claim 5, wherein the memory containing the back-calculated diagnostic-code values is contained within the sensor.

10. The apparatus of claim 5, wherein the memory containing the back-calculated diagnostic-code values is external to the sensor.