Abstract: An apparatus for implementing a minimum toggle rate guarantee may comprise first, second, and third circuitries. The first circuitry may calculate a sequence of values for an internal bus inversion signal based upon a sequence of values for a plurality of internal Input/Output (IO) signals. The second circuitry may establish a sequence of values for an external bus inversion signal by selecting between the sequence of values for the internal bus inversion signal and a sequence of substantially random values. The third circuitry may set the values for a plurality of external IO signals to inverted values of the plurality of internal signals when respectively corresponding sequence of values for the external bus inversion signal have a first value, and to values of the plurality of internal signals when respectively corresponding sequence of values for the external bus inversion signal have a second value.

Abstract: An apparatus for implementing a minimum toggle rate guarantee may comprise first, second, and third circuitries. The first circuitry may calculate a sequence of values for an internal bus inversion signal based upon a sequence of values for a plurality of internal Input/Output (IO) signals. The second circuitry may establish a sequence of values for an external bus inversion signal by selecting between the sequence of values for the internal bus inversion signal and a sequence of substantially random values. The third circuitry may set the values for a plurality of external IO signals to inverted values of the plurality of internal signals when respectively corresponding sequence of values for the external bus inversion signal have a first value, and to values of the plurality of internal signals when respectively corresponding sequence of values for the external bus inversion signal have a second value.

Abstract: Methods and apparatus disclosed herein may be used to establish framing more efficiently in communication protocols with block-coded forward error correction. Such protocols generally involve the check of different bit-alignments searching for positions that yield zero syndromes. The search can be undesirably slow, particularly in the presence of received errors. The presently-disclosed bit-alignment testing technique reduces this search time by checking the syndrome at each data word as if that data word was the last of a code. In other words, the word positions are effectively checked without a prior assumption as to which words are the first and last of the code. This reduces the task to the number of different bit-alignments possible within a single data word, rather than the number of bit-alignments possible in a complete FEC code. In one implementation, the lock time is reduced by approximately 50 times when compared to a straightforward solution.

Abstract: Methods and apparatus disclosed herein may be used to establish framing more efficiently in communication protocols with block-coded forward error correction. Such protocols generally involve the check of different bit-alignments searching for positions that yield zero syndromes. The search can be undesirably slow, particularly in the presence of received errors. The presently-disclosed bit-alignment testing technique reduces this search time by checking the syndrome at each data word as if that data word was the last of a code. In other words, the word positions are effectively checked without a prior assumption as to which words are the first and last of the code. This reduces the task to the number of different bit-alignments possible within a single data word, rather than the number of bit-alignments possible in a complete FEC code. In one implementation, the lock time is reduced by approximately 50 times when compared to a straightforward solution.

Abstract: In a digital system a circuit differentially drives a transmission line, which is open or lightly loaded at the receiving end. A change from a logical ‘1’ to a logical ‘0’ or vice versa is initiated by shorting the two conductors of the transmission line at the transmitting end. A wave then propagates towards the receiver where it is reflected. Just before the reflected wave returns to the drive circuit, the drive circuit is reconfigured in two steps. In the first step each conductor is connected through a matching impedance to the new potential finally required for that conductor. In the second step the short between the two conductors is removed. When the reflected wave reaches the driver, the transfer of charge is complete. Most of the charge required for the change has then been transferred directly from one conductor to the other instead of being sourced by the external power supply.