Automatic polarity detection and correction method and apparatus employing linkpulses
US5257287A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 30, 1990 |
| Grant date | Oct 26, 1993 |
| Priority date | — |
| Expiry date | Nov 30, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4904
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A differential receiver incorporated into a MAU which receives both Manchester packets and linkpulses according to the IEEE 802.3 10Base-T standard has polarity detection and correction circuit for automatically detecting a reversed polarity for RD input lines. The differential receiver samples incoming pulses for time, amplitude and pulse width qualification and makes a preliminary polarity determination based upon polarity of such qualified pulses. This preliminary polarity allows a linktest state machine to transition to a link.sub.-- pass state, enabling output drivers of the MAU. Additionally, the linkpulse polarity information initially makes a polarity determination for the entire differential receiver which asserts a FIX POLARITY signal. The FIX POLARITY signal controls a correction circuit which internally remedies reversed input lines. Preferably, the correction circuit internally reroutes the signals. An ETD polarity circuit makes polarity determinations from any ETD information received, as effected by the correction circuit. The ETD polarity circuit independently controls the linkpulse polarity determinations and conflicting determinations are resolved in favor of the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.