Reset circuit and reset method

• US 20050152443A1
• Filed: 01/05/2005
• Published: 07/14/2005
• Est. Priority Date: 01/14/2004
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Ueno, Tsukasa
• Granted Patent: US 7,474,622 B2
• Time in Patent Office: Days
• US Class Current: 375/224
• 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 device is reset by using link information which indicates whether a physical layer is connected or disconnected to an external interface.

2. The reset circuit claimed in claim 1, having a reset method for resetting a communication device by judging the disconnection of communication based on the link information input from an interface circuit connected to an external interface.

3. The reset circuit claimed in claim 1, comprising:

a link disconnection judging circuit for judging whether or not link is disconnected based on the link information input from the interface circuit connected to the external interface;

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

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

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

resetting system when the time measured in the previous step is over the first predetermined time;

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

6. A resetting method for a communication device claimed in claim 4, wherein, the first and second predetermined times can be reconfigured after once the predetermined times are configured.

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 a physical layer is connected or disconnected to an external interface;

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

resetting system when the time measured in the previous step is over the first predetermined time;

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

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

7. A resetting method for a communication device claimed in claim 5, wherein, the first and second predetermined times can be reconfigured after once the predetermined times are configured.