High speed cross point switch routing circuit with word-synchronous serial back plane
US6377575B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 5, 1998 |
| Grant date | Apr 23, 2002 |
| Priority date | — |
| Expiry date | Aug 5, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2012/5684
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An asynchronous serial crosspoint switch is word synchronized to each of a number of transceiver circuits. The crosspoint switch circuit generates both a master bit clock and a master word clock signal. A transceiver circuit recovers the master bit clock signal from an incoming high-speed serial data stream using a clock and data recovery circuit. The recovered bit clock signal is used as a timing signal by which data is serialized and transmitted to the crosspoint switch circuit. The data stream transmitted to the switch circuit is frequency locked to the master bit clock signal, such that the serial data stream need only be phase adjusted with a data recovery circuit. To recover word timing, the switch circuit issues alignment words to the transceivers during link initialization. The transceivers perform word alignment and establish a local word lock. Alignment words are then reissued to the switch circuit using the local word clock. The switch circuit compares the boundary of the received word clock to the master word clock and, if misaligned, the transceiver shifts its transmitted word by one bit and retries. Necessary edge transition density is provided by overhead bits which …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.