Design And Implementation Of The Framer For Gigabit Ethernet

Gigabit Ethernet has became the main network technique among tributary services of the existed communications network. By the establishment of standards for synchronous Ethernet and the release of IEEE 1588 V2, clock can be restored through the physical layer of the Ethernet or the time can be synchronized through IEEE 1588 messages. All these provide a different solution way for next-generation IP communication networks.The encapsulation of the gigabit Ethernet data plays an important role during the transmission of gigabit data. Whether the framing module is robust directly affects the quality of the entire service transmitted and the precision of the synchronization.This paper implements the framing module for gigabit Ethernet data. Traditional asynchronous Ethernet transmission and synchronous Ethernet transmission are supported, at the same time, the network time synchronization is achieved through the IEEE 1588 messages. In asynchronous mode, the gigabit Ethernet data are packed into GFP frame by 8b/10b decoding module, 64b/65b encoding module, and GFP encapsulation module, and then the gigabit Ethernet data flow into mapping module. Under self-loop test, the gigabit Ethernet data can be completely recovered by GFP de-encapsulation module, 64b/65b decoding module and 8b/10b encoding mnodule. Ethernet-100ppm frequency offset can be tolerated through the velocity adaptation module to achieve the asynchronous Ethernet transmission. In synchronous Ethernet mode, not only the transparency of Gigabit Ethernet data transmission is completed, but also the clock in the PHY layer is restored, and all requirements can be met. In addition, by dealing with IEEE 1588 packets, and combining with IP CORE designed by the other department in the company, a new, low-cost, high-precision means is achieved for time synchronization of Ethernet.