Method of arbitrating access to a data bus and apparatus therefor

• US 5,640,511 A
• Filed: 01/24/1994
• Issued: 06/17/1997
• Est. Priority Date: 02/22/1985
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Krampe, Wolfgang, Dais, Siegfried, Botzenhardt, Wolfgang, Kiencke, Uwe, Litschel, Martin
• Primary Examiner(s): Nguyen, Hoa T.
• Application Number:
  US08/185,024
• Time in Patent Office: 1,240 Days
• Field of Search: 371/20.1, 371/20.5, 371/20.6, 395/185.1, 395/184.01, 364/431.12, 364/514 B, 364/550
• US Class Current: 714/57
• 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: F02D 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue
• CPC Class Codes: F02P 5/1502 using one central computing unit
• CPC Class Codes: G06F 11/0736 in functional embedded systems, i.e. in a data processing system designed as a combination of hardware and software dedicated to performing a certain function testing or monitoring of automated control systems G05B23/02
• CPC Class Codes: G06F 11/0739 in a data processing system embedded in automotive or aircraft systems
• CPC Class Codes: G06F 11/0745 in an input/output transactions management context input/output processing in general G06F13/00
• CPC Class Codes: G06F 11/0763 by bit configuration check, e.g. of formats or tags
• CPC Class Codes: G06F 11/0772 Means for error signaling, e.g. using interrupts, exception flags, dedicated error registers
• CPC Class Codes: G06F 11/10 Adding special bits or symbols to the coded information, e.g. parity check, casting out 9's or 11's
• CPC Class Codes: G06F 13/374 using a self-select method with individual priority code comparator
• CPC Class Codes: H04L 1/0082 fields explicitly indicating existence of error in data being transmitted, e.g. so that downstream stations can avoid decoding erroneous packet; relays
• CPC Class Codes: H04L 12/40163 by assigning priority to messages according to a message field
• CPC Class Codes: H04L 12/4135 using bit-wise arbitration
• CPC Class Codes: H04L 2001/0094 Bus
• CPC Class Codes: H04L 2012/40273 the transportation system being a vehicle
• CPC Class Codes: H04L 25/026 Arrangements for coupling transmitters, receivers or transceivers to transmission lines; Line drivers duplexing arrangements H04L5/14
• CPC Class Codes: H04L 25/0272 Arrangements for coupling to multiple lines, e.g. for differential transmission
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

The invention is directed to a method of handling erroneous messages in a data processing arrangement. The data processing arrangement can be applied to a motor vehicle and includes at least two stations such as a motor control computer, a transmission control computer, and/or a brake control computer. A data line connects the two stations for transmitting messages. The method is performed by causing the station which detected the erroneous message to transmit an error report in response to the erroneous message; and, causing the error report to include a sequence of states or bits which cannot be confused with any sequence of dominant states or bits during error-free data transmission.

Claims

1. A method of handling an erroneous message in one data processing station interconnected with a plurality of other data processing stations interconnected by a serial data bus for transmitting or receiving messages between said stations including said erroneous message which can be transmitted or received by said one station, the messages transmitted on said serial data bus including dominant and non-dominant states or bits, the method comprising the steps of:

causing said one station to detect said erroneous message and to transmit an error report onto said serial data bus in response to said erroneous message thereby alerting the other stations on said serial data bus to said erroneous message;

configuring said error report to include a sequence of dominant states or bits different from any sequence of dominant states or bits during error-free data transmission thereby avoiding confusion therebetween; and

,

transmitting said error report by an error report message and said step of transmitting said error report message including the step of first configuring said error report message to include an error frame portion defined by said dominant states or bits by said one station and closing said error frame portion with an interframe space defined by a sequence of said non-dominant states or bits.

2. The method of claim 1, wherein the step of causing said one station to transmit said error report comprises the step of causing said one station to transmit said error report at any desired point in time including during the transmission of a message.

3. The method of claim 1, wherein said step of configuring said error report message includes the step of making said sequence of non-dominant states or bits longer than said sequence of dominant states or bits by at least one state or bit.

4. The method of claim 1, wherein said stations are associated with different components of a motor vehicle.