The DP8391 Serial Network Interface (SNI) provides the Manchester data encoding and decoding functions for IEEE 802 3 Ethernet Cheapernet type local area networks The SNI interfaces the DP8390 Network Interface Controller (NIC) to the Ethernet transceiver cable When transmitting the SNI converts non-return-to-zero (NRZ) data from the controller and clock pulses into Manchester encoding and sends the converted data differentially to the transceiver The opposite process occurs on the receive path where a digital phase-locked loop decodes 10 Mbit s signals with as much as g 20 ns of jitter