Onboard apparatus, and onboard communication system

• US 9,971,722 B2
• Filed: 08/07/2014
• Issued: 05/15/2018
• Est. Priority Date: 09/11/2013
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Shibata, Minoru, Matsuoka, Hiromichi
• Primary Examiner(s): Sun, Michael
• Application Number:
  US14/917,844
• Publication Number:
  US 20160224499A1
• Time in Patent Office: 1,377 Days
• Field of Search: None
• CPC Class Codes: B60R 16/023 for transmission of signals between vehicle parts or subsystems
• CPC Class Codes: G01C 21/26 specially adapted for navigation in a road network
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: G06F 13/10 Program control for peripheral devices G06F13/14 - G06F13/42 take precedence
• CPC Class Codes: G06F 13/4022 using switching circuits, e.g. switching matrix, connection or expansion network G06F13/4009 takes precedence
• CPC Class Codes: G06F 3/00 Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements

Abstract

An onboard apparatus comprising a connection portion, a control block, and a bus switch is provided. The connection portion connects with an external device mounted to a vehicle, and includes at least a data terminal to input and output a communication data and a control terminal to output a communication availability signal that indicates communication is available or not. The control block performs data communication with the external device, which is connected to the connection portion. The bus switch, according to a permission signal, changes a non-conduction state to a conduction state of a transmission path from the control block to the data terminal. A signal level of the permission signal varies when an output of the control block is stabilized after the onboard apparatus starts.

Claims

1. An onboard apparatus comprising:

a connection portion that connects with an external device mounted to a vehicle, and includes at least a data terminal to input and output a communication data and a control terminal to output a communication availability signal that indicates whether communication is available or not;

a control block that performs data communication with the external device, which is connected to the connection portion; and

a bus switch that, according to a permission signal, changes a non-conduction state to a conduction state of a transmission path from the control block to the data terminal, wherein a signal level of the permission signal varies when an output of the control block is stabilized after the onboard apparatus starts, and

the permission signal is provided by

a reset signal generated by a start control portion to control the reset state of the control block, or

a signal generated by the control block in synchronization with the reset signal.

2. The onboard apparatus according to claim 1, comprising:

an internal power supply that operates on power supplied from an external power supply and supplies power at a supply voltage that is different from the external power supply; and

the start control portion

maintains a reset state of the control block at a timing to start the onboard apparatus,

starts the internal power supply in response to reception of a start instruction starting the control block, and releases the reset state of the control block at a timing to stabilize an output voltage of the internal power supply.

3. The onboard apparatus according to claim 2, wherein:

the control block includes a microcomputer containing a CPU core portion and an interface portion;

the interface portion operates on power supplied from the external power supply; and

the CPU core portion operates on power supplied from the internal power supply.

4. The onboard apparatus according to claim 1, wherein:

the connection portion is provided by a USB interface.

5. An onboard communication system comprising:

the onboard apparatus according to claim 1; and

an external device connected to the connection portion,

wherein;

when the communication availability signal is set to a signal level indicating that communication is unavailable, and when the external device identifies a signal level change detected in the communication data, the external device determines as an error and disables communication.

6. An onboard apparatus comprising:

a connection portion that connects with an external device mounted to a vehicle, and includes at least a data terminal to input and output a communication data and a control terminal to output a communication availability signal that indicates whether communication is available or not;

a control block that performs data communication with the external device, which is connected to the connection portion;

a bus switch that, according to a permission signal, changes a non-conduction state to a conduction state of a transmission path from the control block to the data terminal, wherein a signal level of the permission signal varies when an output of the control block is stabilized after the onboard apparatus starts;

an internal power supply that operates on power supplied from an external power supply and supplies power at a supply voltage that is different from the external power supply; and

a start control portion that

maintains a reset state of the control block at a timing to start the onboard apparatus,

starts the internal power supply in response to reception of a start instruction starting the control block, and

releases the reset state of the control block at a timing to stabilize an output voltage of the internal power supply,

wherein;

the permission signal is provided by

a reset signal generated by the start control portion to control the reset state of the control block, or

a signal generated by the control block in synchronization with the reset signal.

7. The onboard apparatus according to claim 6, wherein:

the control block includes a microcomputer containing a CPU core portion and an interface portion;

the interface portion operates on power supplied from the external power supply; and

the CPU core portion operates on power supplied from the internal power supply.

8. The onboard apparatus according to claim 6, wherein:

the connection portion is provided by a USB interface.

9. An onboard communication system comprising:

the onboard apparatus according to claim 6; and

an external device connected to the connection portion,

wherein;

when the communication availability signal is set to a signal level indicating that communication is unavailable, and when the external device identifies a signal level change detected in the communication data, the external device determines as an error and disables communication.