11.
RX Analog Front End
The RX analog front end (AFE) is an ADC-based input differential buffer. It has the following
features:
• Configurable RX termination voltage
• Calibrated termination resistors
Figure 37:
RX Analog Front End
+
–
+
–
UltraScale Device
Board
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 defines 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
) and brought to the top
level of the design.
Chapter 4: Receiver
UG581 (v1.0) January 4, 2019
Virtex Ult GTM Transceivers
85