Method and apparatus for processing data in controller area network

• US 7,738,462 B2
• Filed: 10/16/2006
• Issued: 06/15/2010
• Est. Priority Date: 10/17/2005
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Hwang, Hee Chang
• Primary Examiner(s): Vu; Huy D
• Assistant Examiner(s): MIAN, OMER S
• Application Number:
  US11/580,860
• Publication Number:
  US 20070091932A1
• Time in Patent Office: 1,338 Days
• Field of Search: 370/475, 370/359, 370/503, 370/509, 370/510, 370/511, 370/512, 370/514, 370/516, 370/354, 370/356, 370364-366, 709/233
• US Class Current: 370/395.1
• CPC Class Codes: H04L 12/4135 using bit-wise arbitration
• CPC Class Codes: H04L 2012/40215 Controller Area Network CAN
• CPC Class Codes: H04L 2012/40273 the transportation system being a vehicle

Abstract

A method and apparatus for processing data in a Controller Area Network (CAN) are discussed. In an embodiment of this invention, dummy data is added to data to be transmitted via a CAN message, and information indicating that the dummy data is added is transmitted via the CAN message. A length of the dummy data is determined such that data to be transmitted via the CAN message becomes a predetermined length, and data in which five or more successive bits do not have a same value is added as the dummy data. The information is included in a field indicating a length of data to be transmitted via the CAN message, and is indicated by a value within a reserved range of the field. Accordingly, data processing efficiency can be improved, and flexible CAN communication can be performed via the CAN message.

Claims

1. A method of processing data in a controller area network (CAN), the method comprising:

adding second data to first data in a CAN message to be transmitted; and

transmitting information, in a data length code (DLC) of the CAN message, indicating that the second data has been added, wherein a value of bits of the DLC that indicates a length of the second data is greater than a value of bits of the DLC that indicates a length of the first data,

wherein the second data includes one or more bytes having an identical value, a first bit of the second data has a value different from a last bit of the first data, first and last bits in each byte have different values, first and fifth bits in each byte have different values, and fourth and last bits in each byte have different values,

wherein the information is included in a field indicating a length of data to be transmitted in the CAN message,

wherein the information is indicated by a value within a reserved range of the field, and

wherein the length of the first data corresponds to a value of lower bits that remain after a most significant bit (MSB) is subtracted from a value within the reserved range of the field.

2. The method as set forth in claim 1, wherein a length of the added second data is a value that is determined such that a sum of lengths of the first data and the second data is a predetermined length.

3. The method as set forth in claim 2, wherein the predetermined length is 8 bytes.

4. The method as set forth in claim 2, wherein the second data is data in which there are no five or more successive bits having an identical value.

5. The method as set forth in claim 1, wherein each of the bytes of the second data has a value of 0×

0F or 0×

F0.

13. The method as set forth in claim 1, wherein the DLC is not included in a data frame of the CAN message.

6. A method of processing data in a controller area network (CAN), the method comprising:

determining a length of first data to be transmitted in a CAN message based on information included in a data length code (DLC) of the received CAN message; and

receiving the first data corresponding to the determined length,

wherein, when the information indicates that second data has been added to the first data, the method further comprises the step of extracting data except the second data from the received first data, and a value of bits of the DLC that indicates a length of the second data is greater than a value of bits of the DLC that indicates a length of the first data,

wherein the second data includes one or more bytes having an identical value, a first bit of the second data has a value different from a last bit of the first data, first and last bits in each byte have different values, first and fifth bits in each byte have different values, and fourth and last bits in each byte have different values,

wherein the information is included in a field indicating a length of data to be transmitted in the CAN message,

wherein the information is indicated by a value within a reserved range of the field, and

wherein the length of the first data corresponds to a value of lower bits that remain after a most significant bit (MSB) is subtracted from a value within the reserved range of the field.

7. The method as set forth in claim 6, wherein, when the information indicates that the second data has been added to the first data, the second data has a length that causes a sum of the first and second data to have a length of 8 bytes.

14. The method as set forth in claim 6, wherein the DLC is not included in a data frame of the CAN message.

8. An apparatus for processing data in a controller area network (CAN), the apparatus comprising:

a CAN controller configured to generate a CAN message including data to be transmitted and transmit the generated CAN message through a CAN bus, or receive the CAN message transmitted through the CAN bus and extract data from the received CAN message; and

a micro-controller configured to transmit data through the CAN controller, or to perform operational control of corresponding devices using the data extracted from the received CAN message,

wherein, the CAN controller selectively adds second data to first data when transmitting the first data in the CAN message, and transmits information, in a data length code (DLC) of the CAN message, indicating that the second data has been added in the CAN message when adding the second data to the first data, and a value of bits of the DLC that indicates a length of the second data is greater than a value of bits of the DLC that indicates a length of the first data,

wherein the second data includes one or more bytes having an identical value, a first bit of the second data has a value different from a last bit of the first data, first and last bits in each byte have different values, first and fifth bits in each byte have different values, and fourth and last bits in each byte have different values,

wherein the information is included in a field indicating a length of data to be transmitted in the CAN message, and is indicated by a value within a reserved range of the field, and

wherein the length of the first data corresponds to a value of lower bits that remain after a most significant bit (MSB) is subtracted from a value within the reserved range of the field.

9. The apparatus as set forth in claim 8, wherein a length of the added second data is a value that is determined such that a sum of lengths of the first data and the second data is 8 bytes.

10. The apparatus as set forth in claim 9, wherein the second data is data in which there are no five or more successive bits having an identical value.

15. The apparatus as set forth in claim 8, wherein the DLC is not included in a data frame of the CAN message.

11. An apparatus for processing data in a controller area network (CAN), the apparatus comprising:

a CAN controller configured to generate a CAN message including data to be transmitted and transmit the generated CAN message through a CAN bus, or to receive the CAN message transmitted through the CAN bus and extract data from the received CAN message; and

a micro-controller configured to transmit data through the CAN controller, or to perform operational control of corresponding devices using the data extracted from the received CAN message,

wherein the CAN controller determines a length of first data to be transmitted in the CAN message based on information included in a data length code (DLC) of the received CAN message, receives a number of bytes of the first data equal to the determined length, when the information indicates that second data has been added to the first data, extracts data except the second data from the received first data, and a value of bits of the DLC that indicates a length of the second data is greater than a value of bits of the DLC that indicates a length of the first data,

wherein the second data includes one or more bytes having an identical value, a first bit of the second data has a value different from a last bit of the first data, first and last bits in each byte have different values, first and fifth bits in each byte have different values, and fourth and last bits in each byte have different values,

wherein the information is included in a field indicating a length of data to be transmitted in the CAN message, and is indicated by a value within a reserved range of the field, and

wherein a length of the extracted data corresponds to a value of lower bits that remain after a most significant bit (MSB) is subtracted from a value within the reserved range of the field.

12. The apparatus as set forth in claim 11, wherein, when the information indicates that the second data has been added to the first data, the second data has a length that causes a sum of the first and second data to have a length of 8bytes.

16. The apparatus as set forth in claim 11, wherein the DLC is not included in a data frame of the CAN message.