A system to convert upstream burst mode data into continuous mode data in a passive optical network (PON) is provided herein. The system includes a burst mode Serializer/Deserializer (SerDes) that recovers a clock and burst mode data from an Optical Network Unit (ONU). The burst mode unit recovers the burst mode data based on a start time of burst mode data transmission by the ONU and a round-trip time between the ONU and an Optical Line Terminal (OLT). The system further includes a continuous mode SerDes that is coupled to the burst mode SerDes. The continuous mode SerDes is configured to receive the recovered clock and recovered burst mode data from the burst mode SerDes and convert the burst mode data into continuous mode data by buffering and padding the burst mode data based on the recovered clock. The continuous mode Serdes is configured to transmit the continuous mode data to the OLT.