Receiver OFFSET Control, OFFSET_CNTRL, is available for some I/O standards on UltraScale devices to compensate for process variations. OFFSET_CNTRL can only be assigned to high-performance (HP) I/Os.
In HP I/O banks, for a subset of I/O standards, the UltraScale architecture provides the option of canceling the inherent offset of the input buffers that occurs due to process variations (up to ±35 mV).
This feature is available for input and bidirectional buffer primitives.
Offset calibration requires building control logic into your interconnect logic design. Refer to the UltraScale Architecture SelectIO Resources User Guide (UG571) [Ref 8] for more information.
Architecture Support
UltraScale devices.
Applicable Objects
•Ports (get_ports)
°Any top-level port
Value
The valid values for the OFFSET_CNTRL attribute are:
•CNTRL_NONE: Do not enable offset cancellation (default)..
•FABRIC: Invokes the offset cancellation feature in an I/O bank.
IMPORTANT: There must be an offset control circuit on the fabric to handle the offset cancellation.
Syntax
Verilog and VHDL Syntax
Not applicable
XDC Syntax
The OFFSET_CNTRL attribute uses the following syntax in the XDC file:
set_property OFFSET_CNTRL <value> [get_ports port_name]
Where:
•set_property OFFSET_CNTRL enables offset cancellation feature.
•<value> is one of the valid OFFSET_CNTRL values.
•port_name is an input or bidirectional port connected.
Affected Steps
•Placement
•Routing