Abstract: Characteristic signal state patterns in a self-clocking digital code such as delay modulation (DM), or Miller, coding are used to control a data transmission system. A DM signal is examined (16, 17) for a double-bit-rate information state pattern that is characteristic of a nonreturn-to-zero (NRZ) ONE-ZERO-ONE bit-rate sequence. Detection of the pattern produces a synchronizing pulse that is used to set (20) a clock pulse train to a predetermined signal state. That train is used for sampling (26) time-adjacent, double-bit-rate, input signal, information states in the DM signal to indicate corresponding NRZ states. An NRZ-to-DM encoder (FIG. 7) is also shown, as is one embodiment of each of the encoder (FIG. 10) and decoder (FIG. 11) using read only memory and register logic. Further shown are a detection (46-49) of other double-bit-rate patterns as error indications and a combined use (FIG. 11) of the error and synchronizing indications for end-to-end signaling.

Abstract: Complementary outputs of a differential amplifier are individually peak detected and the resulting signals are applied to the amplifier differential input in a manner to cause the output peak excursions to have substantially the same direct current levels. This causes the crossover of the two outputs to occur at the midpoint of the signal swing regardless of the input signal peak-to-peak swing, at whatever level.