US-12621021-B2 - Ethernet device that performs cable diagnosis by using IEEE 802.3 compliant waveform and associated ethernet cable diagnosis method

Abstract

An Ethernet device includes a link test pulse (LTP) generator circuit, a hybrid circuit, a transmit (TX) circuit, a receive (RX) circuit, and a post-processing circuit. The LTP generator circuit generates an LTP signal that is compliant with an IEEE 802.3 standard. The TX circuit transmits the LTP signal to an Ethernet cable through the hybrid circuit. The RX circuit receives an RX signal from the hybrid circuit during a period in which the LTP signal is transmitted through the hybrid circuit. The post-processing circuit performs a cable diagnosis of the Ethernet cable according to the RX signal.

Inventors

• Chia-Hsing Hsu
• Wei-Ling Li

Assignees

• AIROHA TECHNOLOGY CORP.

Dates

Publication Date

20260505

Application Date

20231113

Claims (18)

1. 1 . An Ethernet device comprising: a link test pulse (LTP) generator circuit, arranged to generate an LTP signal that is compliant with an IEEE 802.3 standard; a hybrid circuit; a transmit (TX) circuit, arranged to transmit the LTP signal to an Ethernet cable through the hybrid circuit; a receive (RX) circuit, arranged to receive an RX signal from the hybrid circuit during a period in which the LTP signal is transmitted through the hybrid circuit; and a post-processing circuit, arranged to perform a cable diagnosis of the Ethernet cable according to the RX signal; wherein the RX signal comprises a plurality of sample values at different time instances, and the post-processing circuit is arranged to accumulate the sample values to generate an accumulation result, and identify a cable status of the Ethernet cable according to the accumulation result.
2. 2 . The Ethernet device of claim 1 , wherein the LTP signal is a fast link pulse (FLP) of Auto-Negotiation (AN) or a normal link pulse (NLP) of 10BASE-T.
3. 3 . The Ethernet device of claim 1 , wherein the post-processing circuit is arranged to compare the accumulation result and a pre-defined threshold to identify the cable status of the Ethernet cable.
4. 4 . The Ethernet device of claim 1 , wherein the RX signal is received from the hybrid circuit with echo cancellation involved in generation of the RX signal.
5. 5 . The Ethernet device of claim 1 , wherein the RX signal is received from the hybrid circuit without echo cancellation involved in generation of the RX signal.
6. 6 . An Ethernet device comprising: a link test pulse (LTP) generator circuit, arranged to generate an LTP signal that is compliant with an IEEE 802.3 standard; a hybrid circuit; a transmit (TX) circuit, arranged to transmit the LTP signal to an Ethernet cable through the hybrid circuit; a receive (RX) circuit, arranged to receive an RX signal from the hybrid circuit during a period in which the LTP signal is transmitted through the hybrid circuit; and a post-processing circuit, arranged to perform a cable diagnosis of the Ethernet cable according to the RX signal; wherein the RX signal comprises a plurality of sample values at different time instances in a forward direction, and the post-processing circuit is arranged to identify a position of a cable problem of the Ethernet cable through sequentially checking sample values of the RX signal in a backward direction.
7. 7 . The Ethernet device of claim 6 , wherein the post-processing circuit is arranged to sequentially check the sample values of the RX signal in the backward direction by comparing each of the sample values and a pre-defined threshold.
8. 8 . The Ethernet device of claim 6 , wherein the RX signal is received from the hybrid circuit with echo cancellation involved in generation of the RX signal.
9. 9 . The Ethernet device of claim 6 , wherein the RX signal is received from the hybrid circuit without echo cancellation involved in generation of the RX signal.
10. 10 . An Ethernet cable diagnosis method comprising: generating a link test pulse (LTP) signal that is compliant with an IEEE 802.3 standard; transmitting the LTP signal to an Ethernet cable through a hybrid circuit; receiving a receive (RX) signal from the hybrid circuit during a period in which the LTP signal is transmitted through the hybrid circuit; and performing a cable diagnosis of the Ethernet cable according to the RX signal; wherein the RX signal comprises a plurality of sample values at different time instances, and performing the cable diagnosis of the Ethernet cable according to the RX signal comprises: accumulating the sample values to generate an accumulation result; and identifying a cable status of the Ethernet cable according to the accumulation result.
11. 11 . The Ethernet cable diagnosis method of claim 10 , wherein the LTP signal is a fast link pulse (FLP) of Auto-Negotiation (AN) or a normal link pulse (NLP) of 10BASE-T.
12. 12 . The Ethernet cable diagnosis method of claim 10 , wherein identifying the cable status of the Ethernet cable according to the accumulation result comprises: comparing the accumulation result and a pre-defined threshold to identify the cable status of the Ethernet cable.
13. 13 . The Ethernet cable diagnosis method of claim 10 , wherein the RX signal is received from the hybrid circuit with echo cancellation involved in generation of the RX signal.
14. 14 . The Ethernet cable diagnosis method of claim 10 , wherein the RX signal is received from the hybrid circuit without echo cancellation involved in generation of the RX signal.
15. 15 . An Ethernet cable diagnosis method comprising: generating a link test pulse (LTP) signal that is compliant with an IEEE 802.3 standard; transmitting the LTP signal to an Ethernet cable through a hybrid circuit; receiving a receive (RX) signal from the hybrid circuit during a period in which the LTP signal is transmitted through the hybrid circuit; and performing a cable diagnosis of the Ethernet cable according to the RX signal; wherein the RX signal comprises a plurality of sample values at different time instances in a forward direction, and performing the cable diagnosis of the Ethernet cable according to the RX signal comprises: identifying a position of a cable problem of the Ethernet cable through sequentially checking sample values of the RX signal in a backward direction.
16. 16 . The Ethernet cable diagnosis method of claim 15 , wherein identifying the position of the cable problem of the Ethernet cable through sequentially checking sample values of the RX signal in a backward direction comprises: comparing each of the sample values and a pre-defined threshold.
17. 17 . The Ethernet cable diagnosis method of claim 15 , wherein the RX signal is received from the hybrid circuit with echo cancellation involved in generation of the RX signal.
18. 18 . The Ethernet cable diagnosis method of claim 15 , wherein the RX signal is received from the hybrid circuit without echo cancellation involved in generation of the RX signal.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cable diagnosis design, and more particularly, to an Ethernet device that performs a cable diagnosis by using an IEEE 802.3 compliant waveform and an associated Ethernet cable diagnosis method. 2. Description of the Prior Art The Ethernet network might have a link failure issue during network establishment due to many reasons. For example, the link failure issue may result from an Ethernet cable being unplugged or a damaged Ethernet cable being an open or short circuit. It becomes much more difficult for troubleshooting due to the complexity of large Ethernet topology. In this case, a cable diagnosis algorithm is an optimal solution for Ethernet networking troubleshooting. A traditional cable diagnosis algorithm may require a transmitter to send some specific waveforms (e.g., multiple step waves or pseudo random signals) which are not compliant with IEEE 802.3 Auto-Negotiation (AN) and may cause some inter-operability-test issue. Thus, there is a need for an innovative Ethernet cable diagnosis design which does not affect the IEEE 802.3 Ethernet system. SUMMARY OF THE INVENTION One of the objectives of the claimed invention is to provide an Ethernet device that performs a cable diagnosis by using an IEEE 802.3 compliant waveform and an associated Ethernet cable diagnosis method. According to a first aspect of the present invention, an exemplary Ethernet device is disclosed. The exemplary Ethernet device includes a link test pulse (LTP) generator circuit, a hybrid circuit, a transmit (TX) circuit, a receive (RX) circuit, and a post-processing circuit. The LTP generator circuit is arranged to generate an LTP signal that is compliant with an IEEE 802.3 standard. The TX circuit is arranged to transmit the LTP signal to an Ethernet cable through the hybrid circuit. The RX circuit is arranged to receive an RX signal from the hybrid circuit during a period in which the LTP signal is transmitted through the hybrid circuit. The post-processing circuit is arranged to perform a cable diagnosis of the Ethernet cable according to the RX signal. According to a second aspect of the present invention, an exemplary Ethernet cable diagnosis method is disclosed. The exemplary Ethernet cable diagnosis method includes: generating a link test pulse (LTP) signal that is compliant with an IEEE 802.3 standard; transmitting the LTP signal to an Ethernet cable through a hybrid circuit; receiving a receive (RX) signal from the hybrid circuit during a period in which the LTP signal is transmitted through the hybrid circuit; and performing a cable diagnosis of the Ethernet cable according to the RX signal. These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating an Ethernet network system according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an LTP waveform represented by the LTP signal S_LTP generated from the LTP generator circuit shown in FIG. 1. FIG. 3 is a diagram illustrating waveforms represented by the RX signal S_RX under a condition that echo cancellation is not enabled/used (HYBRID_EC=off) according to an embodiment of the present invention. FIG. 4 is a diagram illustrating waveforms represented by the RX signal S_RX under a condition that echo cancellation is enabled/used (HYBRID_EC=on) according to an embodiment of the present invention. FIG. 5 is a flowchart illustrating a process of recording sample values of the RX signal S_RX for follow-up cable status identification according to an embodiment of the present invention. FIG. 6 is a flowchart illustrating a process of post-processing recorded sample values of the RX signal S_RX for cable status identification according to an embodiment of the present invention. FIG. 7 is a flowchart illustrating a process of recording sample values of the RX signal S_RX for follow-up position detection according to an embodiment of the present invention. FIG. 8 is a flowchart illustrating a process of post-processing recorded sample values of the RX signal S_RX for position detection of the cable problem according to an embodiment of the present invention. FIG. 9 is a diagram illustrating a comparison of waveforms of the RX signal S_RX obtained for different positions (lengths) of the cable problem. DETAILED DESCRIPTION Certain terms are used throughout the following description and claims, which refer to particular components. As one skilled in the art will appreciate, electronic equipment manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not in function. In the following description and in the claims, the terms “in