DIFF_TERM_ADV - 2023.2 English

The advanced differential termination (DIFF_TERM_ADV) property is intended for use with UltraScale architecture only, and is used to enable or disable the built-in, 100Ω, differential termination for inputs or bidirectional ports. DIFF_TERM_ADV indicates a differential termination method should be used on differential input and bidirectional port buffers, and that the Vivado Design Suite should add on-chip termination to the port.

DIFF_TERM_ADV is only available for inputs and bidirectional ports and can only be used with the appropriate VCCO voltage. The VCCO of the I/O bank must be connected to 1.8V for HP I/O banks, and 2.5V for HR I/O banks to provide 100Ω of effective differential termination. Refer to the UltraScale Architecture SelectIO Resources User Guide (UG571) for more information.

Architecture Support

UltraScale devices.

Applicable Objects

• Ports (get_ports)
  • Input or bidirectional ports connected to a differential input buffer
• Applicable to objects using one of the following IOSTANDARDs:
  • LVDS, LVDS_25, MINI_LVDS_25, SUB_LVDS
  • PPDS_25
  • RSDS_25
  • SLVS_400_25, and SLVS_400_18

Values

TERM_100

Utilize the 100Ω on-chip differential termination.

TERM_NONE

Do not utilize the on-chip differential termination (default).

Note: The TERM_NONE value is the default value when the DIFF_TERM_ADV property is valid, such as for supported IOSTANDARDs and voltage levels. However, where it is not supported, it should not be specified and DIFF_TERM_ADV=TERM_NONE can result in a DRC violation. In these cases you can set the property to a NULL value using one of the following commands:

reset_proeprty DIFF_TERM_ADV [get_ports <port_name>]
-or-
set_property DIFF_TERM_ADV "" [get_ports <port_name>]

Syntax

Verilog Syntax

Not applicable

VHDL Syntax

Not applicable

XDC Syntax

set_property DIFF_TERM_ADV TERM_100 [get_ports <port_name>]

Where:

• set_property DIFF_TERM_ADV can be assigned to input or bidirectional ports.
• port_name is an input or bidirectional port connected to a differential buffer.

XDC Syntax Example:

# Enables differential termination on port named CLK_p 
set_property DIFF_TERM_ADV TERM_100 [get_ports CLK_p]

Affected Steps

• I/O Planning
• report_drc
• report_ssn
• report_power