Framing codes for high-speed parallel data buses

A method of transmitting data comprising:

• transmitting a plurality of serial data streams on a corresponding plurality of lines at a common frequency, said data being transmitted in equal groups of symbols;
• and
• transmitting on an additional line a framing signal composed of groups of symbols corresponding in number to groups of data symbols;
• wherein each group of symbols in the framing signal comprises a majority of symbols capable of representing a first plurality of code words and a second plurality, substantially less than the first plurality, of valid code words, and a minority of symbols which constitute parity check symbols;
• and
• each of said valid code words consists of a first sub-group of similar symbols and a second plurality of similar symbols, wherein for some of said valid code words the symbols in the first sub-group are similar to the symbols in the second sub-group and for other valid code words the symbols in the first sub-group are different from the symbols in the second sub-group.

A method of transmitting data comprising:

• transmitting a plurality of serial data streams on a corresponding plurality of lines at a common frequency, said data being transmitted in equal groups of symbols;
• and
• transmitting on an additional line a framing signal composed of groups of symbols corresponding in number to groups of data symbols;
• wherein each group of symbols in the framing signal comprises a majority of symbols capable of representing a first plurality of code words and a second plurality, substantially less than the first plurality, of valid code words, and a minority of symbols which constitute parity check symbols;
• and
• said method further comprising monitoring a sequence of groups in the framing signal by means of a state machine according to at least one valid sequence, and detecting errors when the state machine detects an illegal sequence.

A method of transmitting data comprising:

• transmitting a plurality of serial data streams on a corresponding plurality of lines at a common frequency, said data being transmitted in equal groups of symbols;
• and
• transmitting on an additional line a framing signal composed of groups of symbols corresponding in number to groups of data symbols;
• wherein each group of symbols in the framing signal comprises a majority of symbols capable of representing a first plurality of code words and a second plurality of valid code words, and a minority of symbols which constitute parity check symbols.