Sliding-window based signal monitoring

Abstract

The invention is generally directed towards monitoring of a signal (M), such as a clock signal or a data signal, by sampling the signal to obtain a discrete sample representation of the signal and analyzing the sample representation. The idea according to the invention is to slide a sample window (SW) over the sampled signal and determine whether the samples currently within the window include a valid transition sequence. In the general case, the existence of a valide signal is confirmed as long as a valid transition sequence is present in at least one of a predetermined number of consecutive sample windows. In order to reduce the need for oversampling in high-frequency applications, the invention furthermore proposes a multi-phase sampling technique according to which a number of phase-shifted sample clocks (S1 to SN) are generated for the purpose of sampling the signal to be monitored. Higher-frequency oversampling is thus replace by a higher resolution in the time domain.

Description

TECHNICAL FIELD OF THE INVENTION The present invention generally relates to signal supervision, and more particularly to a method and device for signal monitoring. BACKGROUND OF THE INVENTION Supervision and monitoring of signals, such as clock signals and data signals, is of vital importance and signal monitors of various types can be found in many digital electronic systems such as telecommunication systems and other digital communication systems. For example, interfaces and clock paths for a synchronous digital system must continuously be supervised in order to maintain high reliability. Basically, a signal monitor is an arrangement for monitoring the behavior and / or status of a signal. As long as the signal behaves as normal, the signal monitor confirms the existence of a valid signal. On the other hand, if the signal behavior deviates from normal, an alarm is normally raised so that appropriate actions can be taken. The performance evaluation of a signal monitor is normally...

AI Technical Summary

Benefits of technology

It is a general object of the present invention to provide a general and robust signal monitoring mechanism.

The invention offers the following advantages: A general and flexibly adaptable monitoring mechanism; Fast detection speed; No need for complex alignment algorithms; User controlled and scalable accuracy and detector resolution; A flexible degree of error correction for metastability situations; Reduced need for oversampling with high-frequency sample clocks; Improved operation frequency range; Parallelism; and Self-monitoring.

Problems solved by technology

This generally means that the signal monitors are customized for signals with certain characteristics, thus making it difficult to adapt the signal monitors to system or application changes that imply supervision of signals with other characteristics.

General detection mechanisms that are capable of handling different types of signals under various conditions are normally very complex and require extensive data processing.

In high-frequency applications, however, the detection time latency is generally far too high to be acceptable.

For high-frequency signals, there is simply not enough time for a complex detection mechanism to detect a signal failure in just a few clock cycles.

However, when the frequency of the monitored signal reaches higher and higher levels, it may not be possible to generate a high-frequency sample clock for oversampling purposes, at least not to a reasonable cost.

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