11. RX FEC
RX Analog Front End
The RX analog front end (AFE) is an ADC-based input dierenal buer. It has the following
features:
• Congurable RX terminaon voltage
• Calibrated terminaon resistors
Figure 37: RX Analog Front End
+
–
+
–
UltraScale DeviceBoard
ACJTAG RX
ACJTAG RX
50Ω
50Ω
MGTAVTT Programmable
FLOAT
MGTAVTT
MGTAVTT
~100 nF
~100 nF
PAD_RTERM_VCOM_MODE
PAD_RTERM_VCOM_LVL
X20922-111918
Ports and Attributes
The following table denes the RX AFE ports.
Table 48: RX AFE ports
Ports Dir Clock Domain Description
CH[0/1]_GTMRXP,
CH[0/1]_GTMRXN
In (Pad) RX Serial Clock Differential complements of one another
forming a differential receiver input pair.
These ports represent pads. The location
of these ports must be constrained (see
Implementation) and brought to the top
level of the design.
Chapter 4: Receiver
UG581 (v1.0) January 4, 2019 www.xilinx.com
Virtex UltraScale+ GTM Transceivers 85