Control device for a vehicle engine

• US 20020089883A1
• Filed: 10/15/2001
• Published: 07/11/2002
• Est. Priority Date: 10/16/2000
• Status: Active Grant

• Current Assignee: Magneti Marelli Powertrain S.p.A. (Magneti Marelli S.p.A.), STMicroelectronics SRL (STMicroelectronics NV)
• Original Assignee: STMicroelectronics SRL (STMicroelectronics NV)
• Inventors: Marceca, Paolo, Ferrari, Alberto, Pezzini, Saverio, Pepi, Alessandro
• Granted Patent: US 6,735,514 B2
• Time in Patent Office: Days
• US Class Current: 365/200
• CPC Class Codes: F02D 41/2422 Selective use of one or more tables
• CPC Class Codes: F02D 41/2435 characterised by the writing medium, e.g. bar code
• CPC Class Codes: F02D 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue
• CPC Class Codes: G11C 16/102 External programming circuits, e.g. EPROM programmers; In-circuit programming or reprogramming; EPROM emulators
• CPC Class Codes: G11C 7/1045 Read-write mode select circuits

Abstract

A control device for a vehicle engine includes a memory unit for storing engine configuration parameters, a processing unit for sending control signals to the engine in accordance with the configuration parameters, and an input/output unit connectible to an external computer to modify the configuration parameters. The control device includes a first portion and a second portion of the memory unit, with each portion being alternately used in an active state for storing a current version of the configuration parameters or in an inactive state for the writing of a new version of the configuration parameters. The processing unit accesses the portion which is in the active state for reading, and the input/output unit accesses the portion which is in the inactive state for writing. An interconnection unit selectively switches one of the portions to the active state and the other of the portions to the inactive state.

Claims

1. A control device for a vehicle engine comprising a memory unit for storing engine configuration parameters, a processing unit for sending control signals to the engine in accordance with the configuration parameters, and an input/output unit connectible to an external computer in order to modify the configuration parameters, said memory unit including a first portion and a second portion, each of which is usable alternatively in an active state for storing a current version of the configuration parameters or in an inactive state for the writing of a new version of the configuration parameters, the processing unit accessing the portion which is in the active state, for reading, and the input/output unit accessing the portion which is in the inactive state, for writing, means being provided for selectively switching one of the portions to the active state and the other of the portions to the inactive state.

2. A control device according to claim 1 in which the first portion and the second portion consist, respectively, of a first bank and of a second bank of a single read-while-write flash E²PROM memory.

3. A control device according to claim 1 in which the current version of the configuration parameters is accessed by the processing unit by means of corresponding addresses of a first space and the new version of the configuration parameters is accessed by the input/output unit by means of corresponding address of a second space, the switching means comprising an indicator of the state of the first portion and of the second portion and means for associating with each address of the first space and of the second space a corresponding location of the first portion or of the second portion, in accordance with the state indicator.

4. A control device according to claim 1 in which the input/output unit sends an interrupt signal to the processing unit in response to a signal of the completion of the writing of the new version of the configuration parameters by the external computer, and the processing unit switches the state indicator in response to the interrupt signal.

5. A control device according to claim 4 in which the configuration parameters are organized in coherent data structures which cannot be modified during a reading operation, the interrupt signal being masked during an operation to read a coherent data structure.

6. A control device according to claim 1 in which the memory unit supplies a signal of the completion of a writing operation to the input/output unit on a dedicated line, the input/output unit accepting a writing command from the external computer only if the completion signal is activated.

7. A control device according to claim 1, further comprising means for writing operating parameters of the engine in the portion which is in the inactive state, the input/output unit reading the operating parameters from the portion which is in the inactive state and supplying the operating parameters read to the external computer in response to a corresponding request signal from the external computer.

8. A control device according to claim 1, further comprising at least one peripheral unit for interfacing with the engine, having a plurality of internal registers, the input/output unit modifying the registers in response to a corresponding request signal from the external computer.

9. A control device according to claim 1 in which the input/output unit includes a serial test interface for exchanging information with the external computer and a further processing unit for accessing internal resources of the control device, independently of the processing unit.

10. A vehicle comprising an engine and the engine control device according to any one of claims 1 to 9.

11. A method of controlling a vehicle engine, comprising the steps of:

storing engine configuration parameters in a memory unit,

sending control signals to the engine in accordance with the configuration parameters, by means of a processing unit,

modifying the configuration parameters by means of an input/output unit connected to an external computer,

providing a first portion and a second portion of the memory unit, each usable alternatively in an active state for storing a current version of the configuration parameters or in an inactive state for the writing of a new version of the configuration parameters,

accessing the portion which is in the active state, for reading, by the processing unit,

accessing the portion which is in the inactive state, for writing, by the input/output unit, and

selectively switching one of the portions to the active state and the other of the portions to the inactive state.