Intel® Cyclone® 10 GX Transceiver PHY User Guide

ID 683054
Date 4/14/2023
Document Table of Contents Programmable Pre-Emphasis

Pre-emphasis can maximize the eye at the far-end receiver. The programmable pre-emphasis module in each transmit buffer amplifies high frequencies in the transmit data signal, to compensate for attenuation in the transmission media.

The pre-tap pre-emphasizes the bit before the transition and de-emphasizes the remaining bits. A different polarity on pre-tap does the opposite.

Table 176.  Pre-Emphasis TapsAll four pre-emphasis taps provide inversion control, shown by negative values.
Pre-Emphasis Tap Number of Settings Channel Loss Compensation (dB)
Second pre-tap 15 2.31
First pre-tap 33 6.62
First post-tap 51 15.56
Second post-tap 25 4.44

You can set pre-emphasis taps through the Quartus Assignment Editor, the Avalon-MM registers, and the QSF settings.