DCI impedance value

http://www.xilinx.com/support/answers/11450.htm

Virtex-II/Virtex-II Pro/Virtex-4/Virtex-5 IBIS/SPICE models - How does an IBIS or SPICE simulation account for the DCI impedance value?

AR#	11450
Part	HW-SelectIO
Last Modified	2007-10-16 00:00:00.0
Status	Active
Keywords	Virtex, DCI, IBIS, SPICE, model, impedance, on, chip, termination, simulate, simulation, reference, resistor, output, input, I/O, IO

Description

Keywords: Virtex, DCI, IBIS, SPICE, model, impedance, on, chip, termination, simulate, simulation, reference, resistor, output, input, I/O, IO

In an IBIS or SPICE simulation of any of the Virtex-II/Virtex-II Pro/Virtex-4/Virtex-5 I/O standards that employ DCI (digitally controlled impedance), how does the simulation account for the impedance value?

Solution

Any IBIS or SPICE model represents a single DCI impedance setting. With the exception of 40 and 65 ohm LVDCI models in the Virtex-II IBIS release, and 25/40/65/75 ohm LVDCI models in the Virtex-II SPICE release, all Virtex-II, Virtex-II Pro, Virtex-4 and Virtex-5 DCI models represent 50 ohms termination.

IBIS models can be downloaded here:
http://www.xilinx.com/xlnx/xil_sw_updates_home.jsp

SPICE models can be downloaded here:
http://support.xilinx.com/support/software/spice/spice-request.htm

If you require a SPICE model for Virtex/-E or Spartan-II/-IIE, please contact Xilinx Customer Support:
http://www.xilinx.com/support/mysupport.htm