Reset circuit and reset method

• US 7,474,622 B2
• Filed: 01/05/2005
• Issued: 01/06/2009
• Est. Priority Date: 01/14/2004
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ueno, Tsukasa
• Primary Examiner(s): LEE, CHI HO A
• Application Number:
  US11/029,002
• Publication Number:
  US 20050152443A1
• Time in Patent Office: 1,462 Days
• Field of Search: None
• US Class Current: 370/242
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A reset circuit and a reset method are provided in order to operate a power switch of the main body of a communication device installed in an inaccessible place such as a remote place or a high-altitude place and to execute a reset by software in the case of having problems with firmware or software of a communication device installed in a remote place. In a reset circuit for a communication device, the device is reset by using link information, which indicates whether a physical layer is connected or disconnected to an external interface.

Claims

1. A reset circuit for a communication device,

wherein the reset circuit is configured to reset the device by using link information which indicates whether a physical layer is connected or disconnected to an external interface, and

wherein the reset circuit comprises:

a link disconnection judging circuit for judging whether the physical layer is disconnected based on the link information input from an interface circuit comprising the physical layer;

a system reset circuit for resetting the communication device by receiving a reset signal from the link disconnection judging circuit; and

a power reset circuit for disconnecting a power source by receiving a reset signal from the link disconnection judging circuit.

2. The reset circuit claimed in claim 1, wherein the reset circuit is configured to receive the link information input from the interface circuit.

3. The reset circuit claimed in claim 2, wherein the external interface is in communication with the communication device via the interface circuit.

4. The reset circuit claimed in claim 1, wherein the communication device is a radio communication device.

5. A resetting method for a communication device comprising the steps of:

judging whether or not a communication is disconnected based on link information which indicates whether a physical layer is connected or disconnected to an external interface;

measuring a time from when the communication is judged to be disconnected by the judging step;

resetting the communication device when the time measured in the previous step is over a first predetermined time;

and/or resetting a power source when the time measured is over a second predetermined time.

6. The resetting method for a communication device claimed in claim 5, wherein the first and second predetermined times can be reconfigured after the predetermined times have been configured.

7. The resetting method claimed in claim 5, wherein resetting the communication device comprises producing a system reset pulse.

8. The resetting method claimed in claim 7, wherein resetting the communication device further comprises applying a reset signal to each section of the communication device in response to the system reset pulse.

9. The resetting method claimed in claim 8, wherein resetting the power source comprises producing a power reset pulse and stopping a supply of a secondary power to said each section of the communication device in response to the power reset pulse.

10. A resetting method for a communication device comprising the steps of:

judging whether or not a communication is disconnected based on link information which indicates a physical layer is connected or disconnected to an external interface;

measuring a time from when the communication is judged to be disconnected by the judging step;

resetting the communication device when the time measured in the previous step is over a predetermined time;

judging whether or not the communication device is up and running correctly after the resetting step; and

resetting a power when the communication device is not judged in the previous step to be correctly up and running.

11. The resetting method for a communication device claimed in claim 10, wherein the predetermined time can be reconfigured after the predetermined time has been configured.

12. The resetting method claimed in claim 10, wherein resetting the communication device comprises producing a system reset pulse.

13. The resetting method claimed in claim 12, wherein resetting the communication device further comprises applying a reset signal to each section of the communication device in response to the system reset pulse.

14. The resetting method claimed in claim 13, wherein resetting the power comprises producing a power reset pulse and stopping a supply of a secondary power to said each section of the communication device in response to the power reset pulse.