In described examples, a retimer includes a reference voltage generator, first, second, third, and fourth comparators, a hit sensor, a window results comparison circuit, and a window control circuit. First inputs of the first, second, third, and fourth comparators receive samples of a data stream. First, second, third, and fourth outputs of the reference voltage generator are coupled to respective second inputs of the first, second, third, and fourth comparators. The third and fourth comparators output to, respectively, first and second inputs of the hit sensor. The hit sensor outputs to an input of the window results comparison circuit. The window results comparison circuit outputs to an input of the window control circuit. The window control circuit outputs to an input of the reference voltage generator.

Multipath clock and data recovery circuits and multipath I/O devices are described that operate to provide flexible I/O paths for serial data communications. Active unidirectional components such as a clock and data recovery circuit may be used to implement different I/O paths. Bandwidth and signal degradation for high-speed serial data transmission is reduced.

Methods, systems, and apparatus for inserting a re-timer signal between a transmitter and a receiver, including receiving, from the transmitter, an input data signal having encoded words, where each encoded word of the encoded words has a word length of a predetermined number of bits; generating, by a re-timer and based on the input data signal, a regenerated clock signal and an output data signal; determining, based on the regenerated clock signal, a timing difference between the input data signal and the output data signal of the re-timer; and applying, by the re-timer and based on the timing difference between the input data signal and the output data signal, a delay to the input data signal to generate a delayed output data signal, such that a timing difference between the input data signal and the delayed output data signal corresponds to N word lengths.

Techniques and devices for differential signal repeating are described. A differential signal repeating method may include receiving an input differential signal pair including first and second input signals received at first and second input terminals, respectively, and generating an output signal at an output terminal. Generating the output signal may include: based on a determination, at a first time, that the first and second input signals represent complementary values, setting a level of the output signal to represent an inverse of the value represented by the first input signal, and based on a determination, at a second time, that the first and second input signals do not represent complementary values, placing the output terminal in a high-impedance state.

In described examples, a retimer includes a reference voltage generator, first, second, third, and fourth comparators, a hit sensor, a window results comparison circuit, and a window control circuit. First inputs of the first, second, third, and fourth comparators receive samples of a data stream. First, second, third, and fourth outputs of the reference voltage generator are coupled to respective second inputs of the first, second, third, and fourth comparators. The third and fourth comparators output to, respectively, first and second inputs of the hit sensor. The hit sensor outputs to an input of the window results comparison circuit. The window results comparison circuit outputs to an input of the window control circuit. The window control circuit outputs to an input of the reference voltage generator.