AN 686: Implementing 9.8 Gbps CPRI in Arria V GT and ST Devices

ID 683613
Date 12/06/2013

1.5. Auto Rate Negotiation

In Arria V GT and Arria V ST FPGAs, a soft PCS implementation supports auto rate negotiation from 9.8304 Gbps to 1.2288 Gbps. Altera recommends to use the hard PCS for CPRI interfaces where the maximum interface data rate is 6.144 Gbps or lower. In this example, the channels are initialized at the highest supported data rate and are switched to successive lower data rates.

Figure 5. Design Block Diagram for Auto Rate Negotiation from 9.8304 Gbps to Lower Data RatesThe following figure shows an example design of auto rate negotiation for 1.2G /2.5G /3.1G /4.9G/ 6.1G/ 9.8G.