AR# 7937: Foundation 2.1i + SP2: How to instantiate LVDS I/O in Foundation Schematics
Foundation 2.1i + SP2: How to instantiate LVDS I/O in Foundation Schematics
Keywords: Foundation, fndtn, LVDS,Virtex-E
General Description: With SP2 support for Virtex-E has been added to Foundation 2.1i. However the schematic libraries do not contain LVDS I/O buffer symbols. How can LVDS pins be instantiated in schematics?
Instead of using LVDS buffers use regular IBUFS and OBUFS. Note that for LVDS inputs only one signal is needed whereas for LVDS outputs both, the positive and the negative output (with an inverter) must be drawn.
In the ucf set the IOSTANDARD=LVDS attribute for all IBUFS and OBUFS that should be LVDS.