RX Equalizer

Versal ACAP GTM Transceivers Architecture Manual (AM017)

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1.0 English

A serial link bit error rate (BER) performance is a function of the transmitter, transmission media, and receiver. The transmission media of the channel is bandwidth-limited and the signal traveling through is subjected to attenuation and distortion.

The GTM receiver in Versal ACAPs is an ADC-based buffer that breaks the equalizer into two domains, analog and digital. The incoming signal first passes through the analog stage consisting of a CTLE and AGC stage. The signal is then digitized by the ADC and passes through the feed-forward equalizer (FFE) and decision feedback equalizer (DFE) before being sampled by the CDR.

Figure 1. GTM RX Equalizer

The combination of the CTLE, FFE, and DFE can compensate for both the pre-cursor and post-cursor of the transmitted symbol. All equalization loops are auto adaptive to handle a wide range of channel profiles and to compensate for any PVT variations.