Apparatus and related method to synchronize operation of serial repeater

An apparatus comprising:

• a serial repeater having a deserializer coupled to a serial output line, and a serializer coupled to the deserializer through a data buffer;
• a phase detector having a first detector input line coupled to the deserializer to detect a write frequency of the deserializer and a second detector input line coupled to the serializer to detect a read frequency of the serializer, wherein the phase detector is configured to (i) output a first code sequence at a rotator input in response to the write frequency being greater than the read frequency, and (ii) output a second code sequence at the rotator input in response to the write frequency being less than the read frequency;
• and
• a phase rotator having a first rotator input line coupled to a phase locked loop (PLL) to receive a clock signal therefrom, a second rotator input line coupled to the rotator input for receiving either one of the first code sequence and the second code sequence from the phase rotator, and an output line coupled to the serializer for transmitting a pacing signal to the serializer,
• wherein the phase rotator is configured to increase the read frequency of the serializer in response to receiving the first code sequence at the first rotator input line and decrease the read frequency of the serializer in response to receiving the second code sequence at the first rotator input line.

A method comprising:

• transmitting a digital signal to a serial repeater, wherein the serial repeater includes a deserializer coupled to a serial output line of a photonic integrated circuit (PIC) die and a serializer coupled to the deserializer through a data buffer;
• determining whether a write frequency of the deserializer is different from a read frequency of the serializer;
• and
• transmitting a pacing signal to the serializer to modify the read frequency of the serializer, wherein the pacing signal increases the read frequency of the serializer in response to the write frequency being greater than the read frequency and decreases the read frequency of the serializer in response to the write frequency being less than the read frequency.