Physical coding sub-layer for transmission of data over multi-channel media

Abstract

A method and apparatus for transporting data over a plurality of serial channels. A plurality of parallel data word are generated from a parallel data word of greater width. The plurality of parallel data words are scrambled in a predetermined manner utilizing a side scrambler to generate a plurality of cipher data words. A first bit is generated for each channel as an exclusive OR function from the cipher data word in the respective channel. A second bit is generated for each channel as an exclusive or function of the respective cipher data word and certain control information. The first bit is appended to the cipher data word for the channel from which it was derived. The second bit is appended to the cipher data word for a channel other than the one from which it was derived. The cipher data word and the first and second bits comprise a parallel extended width information word. The extended width information words are serialized and transmitted across a plurality of serial data channels corresponding in number to the number of parallel extended width information words. Receive logic is provided for each serial channel which converts received serial data to parallel data, obtain word synchronization and achieves aligns the words received over the respective channels to assure avoid word skew misalignment across channels. The received data is descrambled and recombined in the receive logic to obtain the originally transmitted data word. Offset side scramblers are designed so as to reduce near end and far end crosstalk.

What is claimed is:  
     
         1 . A method for transporting data across a plurality of data channels comprising: 
 concurrently generating a plurality of lesser width parallel data words containing parallel data from a greater width parallel data word such that all adjacent bits of said greater width parallel data word are contained in different ones of said lesser width parallel data words, wherein the number of bits in said greater width parallel data word is greater than the number of bits in each of said lesser width parallel data words;    serializing parallel data representative of said plurality of lesser width parallel data words; and    transmitting said serialized data words over a corresponding plurality of distinct serial data channels.    
     
     
         2 . A method for transporting data across a plurality of data channels comprising: 
 concurrently generating a plurality of lesser width width parallel data words containing parallel data from a greater width parallel data word such that all adjacent bits of said greater width parallel data word are contained in different ones of said lesser width parallel data words, wherein the number of bits in said greater width parallel data word is greater than the number of bits in each of said lesser width parallel data words;    scrambling the parallel data in said lesser width parallel data words to form a plurality of scrambled data words;    serializing said scrambled data words; and    transmitting said serialized scrambled data words over a corresponding plurality of distinct serial data channels.