US 6,618,395 B1 · 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.

Claims43

Dependent claims

In a multi-channel data transmission system including segmentation circuitry for dividing a wide parallel data word into a plurality of lesser width parallel data words, and serializers for converting said lesser width parallel data words into serial data streams for transmission over respective serial channels, a method for transmitting information, said method comprising:

obtaining a first data word, at least in part, from each of said lesser width parallel data words;
generating a first crc code from each of said first data words;
exclusive ORing two of said first crc codes with a first control bit to form a first pair of crc output codes and exclusive ORing another two of said first crc codes with a second control bit to form a second pair of crc output codes;
associating each one of said crc output codes with a different one of said first data words to form a plurality of extended width information words, such that each crc output code is associated with an extended width information word containing a first data word other than the first data word from which the respective crc output code was derived;
and
transmitting said extended width information words over a corresponding plurality of serial channels.

3 more elements

A multi-channel data transmission system comprising:

segregation logic for dividing a wide parallel data word into a plurality of lesser width parallel data words;
scrambler logic operative to scramble each of said lesser width parallel data words in a first predetermined manner to provide a corresponding plurality of scrambled data words;
crc generator logic operative to generate first and second crc codes from each of said scrambled data words and to associate said first crc codes with the respective scrambled data word from which the first crc codes were derived to form a plurality of extended width information words corresponding in number to the number of scrambled data words;
encoding logic operative to exclusive OR a first control bit with two of said second crc codes to form a first pair of control encoded crc codes, to exclusive OR a second control bit with two other ones of said second crc codes to form a second pair of control encoded crc codes, and to couple each one of said encoded crc codes to an extended width information word containing a scrambled data word other than the scrambled data word from which the respective control encoded crc code was derived;
a plurality of serial channels;
a plurality of serializers for converting said extended width information words into serialized extended width information words for transmission over corresponding ones of said serial channels;
a plurality of deserializers for receiving said serialized extended width information words and for converting said serialized words into received extended width information words;
word synchronization logic associated with each of said channels, said word synchronization logic operative to utilize the respective first crc code to determine whether proper word framing has been acquired and to provide an indication of word alignment;
and
skew alignment logic operative in response to said indication of word alignment, at least two of said control encoded crc codes and at least two calculated crc codes derived from a selected pair of scrambled data words contained within the corresponding received extended width information words, to determine, over a plurality of scrambled data words, whether said scrambled data words are skew aligned, and to provide an indication of skew alignment.

7 more elements

A method for achieving synchronization in a multi-channel data transmission system comprising:

for each of a plurality of sequentially received first parallel data words:
dividing the first parallel data word into a plurality of lesser width parallel data words, each of said plurality of lesser width parallel data words including a plurality of bits;
scrambling the bits within each of said plurality of lesser width parallel data words in a predetermined manner to obtain a corresponding plurality of cipher data words;
generating a plurality of word framing indicators, each word framing indicator being generated as a first predetermined function of one of said cipher data words;
appending said word framing indicator to the respective cipher data word from which the word framing indicator was generated to form an extended width information word;
generating a plurality of skew alignment indicators corresponding in number to the number of lesser width parallel data words, each one of said skew alignment indicators being generated as a second predetermined function of at least some of the contents of a respective one of said cipher data words;
appending each skew alignment indicator to one of said extended width information words other than the extended with information word containing the cipher data word from which the respective skew alignment indicator was generated;
serializing each one of said extended width information words and transmitting the serialized extended width information words over a corresponding plurality of serial channels;
receiving said serialized extended width information words from said plurality of serial channels;
deserializing said serialized extended width information words to obtain said plurality of extended width information words;
calculating a word framing indicator as said first predetermined function of said cipher data word contained within the respective extended width information word for each extended width information word;
comparing the respective calculated word framing indicator to the word framing indicator transmitted with the respective extended width information word and providing an indication of a word alignment match in the event said calculated word framing indicator matches said transmitted word framing indicator;
and
providing an indication that proper word synchronization has been obtained for each respective channel in the event a predetermined number of matches between said calculated and transmitted word framing indicators over a predetermined number of extended width information words.

11 more elements

A method for achieving synchronization in a multi-channel data transmission system comprising:

for each of a plurality of ordered first parallel data words:
dividing the respective first parallel data word into a plurality of lesser width parallel data words, each of said plurality of lesser width parallel data words including a plurality of bits;
scrambling the bits within each of said plurality of lesser width parallel data words in a predetermined manner to obtain a corresponding plurality of cipher data words;
generating a plurality of word framing indicators, each word framing indicator being generated as a first predetermined function of one of said cipher data words;
appending said word framing indicator to the respective cipher data word from which the word framing indicator was generated to form an extended width information word;
for each cipher data word, in a second predetermined function, exclusive ORing at least some of said bits of the respective cipher data word to form respective skew alignment values;
generating a plurality of skew alignment indicators, wherein each one of said skew alignment indicators is generated as an exclusive OR of the respective skew alignment value with a selected bit of a multibit control value and wherein each control bit of said multibit control value is exclusive ORed with two skew alignment values to form two corresponding skew alignment indicators;
including each skew alignment indicator in one of said extended width information words other than the extended width information word containing the cipher data word from which the respective skew alignment indicator was generated,
serializing each one of said extended width information words and transmitting the serialized extended width information words over a corresponding plurality of serial channels;
receiving said serialized extended width information words from said plurality of serial channels;
deserializing said serialized extended width information words to obtain said plurality of extended width information words;
calculating a word framing indicator as said first predetermined function of said cipher data word contained within the respective extended width information word for each extended width information word;
comparing the calculated word framing indicator to the word framing indicator transmitted with the respective extended width information word and providing an indication of a word alignment match in the event said calculated word framing indicator matches said transmitted word framing indicator;
and
providing an indication that proper word synchronization has been obtained for each respective channel in the event a predetermined number of matches between said estimated and calculated word framing indicators over a predetermined number of extended width information words.

12 more elements

A method for achieving synchronization in a multi-channel data transmission system comprising:

for each of a plurality of ordered parallel data words:
dividing the respective parallel data word into a plurality of lesser width parallel data words, each of said plurality of lesser width parallel data words including a plurality of bits;
scrambling the bits within each of said plurality of lesser width parallel data words in a predetermined manner to obtain a corresponding plurality of cipher data words;
generating a plurality of word framing indicators, each word framing indicator being generated as a first predetermined function of one of said cipher data words;
appending said word framing indicator to the respective cipher data word from which the word framing indicator was generated to form an extended width information word;
generating a plurality of skew alignment values, wherein each of said skew alignment values is generated by a second predetermined function comprising an exclusive OR of at least some of said bits of the respective cipher data word,
generating a plurality of skew alignment indicators, wherein each one of said skew alignment indicators is generated as an exclusive OR of the respective skew alignment value with a selected bit of a multibit control value and wherein each control bit of said multibit control value is exclusive ORed with two skew alignment values to form two corresponding skew alignment indicators;
appending each skew alignment indicator to one of said extended width information words other than the extended with information word containing the cipher data word from which the respective skew alignment indicator was generated;
serializing each one of said extended width information words and transmitting the serialized extended width information words over a corresponding plurality of serial channels;
receiving said serialized extended width information words from said plurality of serial channels;
deserializing said serialized extended width information words to obtain said pluralities of extended width information words;
utilizing said word framing indicators to identify if the respective extended width information words are not properly synchronized on word boundaries;
and
utilizing said skew alignment indicators to identify whether the extended width information words received over said plurality of serial channels are properly aligned across the respective channels.

11 more elements

Dependencies are inferred from the claim text.

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

Life of this patent

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

Life of this patent

Abstract

Claims43