Stratix V Device Handbook: Volume 2: Transceivers

ID 683779
Date 11/23/2021
Document Table of Contents

6.5. Decision Feedback Equalization

Decision feedback equalization (DFE) helps compensate for backplane attenuation because of insufficient bandwidth.

DFE works by estimating the intersymbol interference (ISI) that is imposed by the channel on an incoming bit and canceling out the ISI as that bit is sampled by the CDR circuitry. The advantage of DFE is that it boosts the power of the highest frequency component of the received data without increasing its noise power. Use DFE in conjunction with the transmitter pre-emphasis and receiver linear equalization.

The Transceiver Reconfiguration Controller provides an Avalon-MM user interface to step through the DFE tap settings.

Note: In Stratix V GT devices, the GT channels do not support DFE. This feature is supported in the GX channels.