Table 44: TX Programmable Divider Attribute (cont'd)
Attribute Type Description
TX_PROGDIV_PDBV_DIV5 [2] This attribute is used during the TX programmable divider
ratio selection.
• The attribute must be set to 1’b0 when the desired
divider value is either 16.5, 33, 66, or 132.
• For all other divider values, this should be set to 1’b1.
Ports and Attributes
The following table denes the ports required for TX fabric clock output control.
Table 45: TX Fabric Clock Output Control Ports
Port Dir
Clock
Domain
Description
CH[0/1]_TXOUTCLKSEL[2:0] In Async This port must be set to 3'b000.
CH[0/1]_TXOUTCLK Out Clock Reserved.
CH[0/1]_TXPROGDIVCLK Out Clock TXPROGDIVCLK is the parallel output clock from the
TX programmable divider. This clock is the
recommended output to the interconnect logic
through BUFG_GT.
TX Configurable Driver
The GTM transceiver TX driver is a high-speed voltage-mode dierenal output buer. To
maximize signal integrity, it includes these features:
• Dierenal voltage control
• Two pre-cursor, and one post-cursor transmit pre-emphasis
• Two modulaon schemes: NRZ and PAM4
• Calibrated terminaon resistors
Chapter 3: Transmitter
UG581 (v1.0) January 4, 2019 www.xilinx.com
Virtex UltraScale+ GTM Transceivers 77