AR# 10872: 3.1i Virtex-II PAR - Problem found with LVDS legality checking.
3.1i Virtex-II PAR - Problem found with LVDS legality checking.
Keywords: LVDS, PAR, ERROR:Place:1682, place, placer, placement, LOC
General Description: When I attempt to lock down the LVDS I/Os based on the location from a previous valid placement, I encounter errors that terminate the PAR run:
ERROR:Place:1682 - The LVDS Pair of IOBs L3_TX_CAD0_H and L3_TX_CAD0_L are locked in a set of non-paired sites AE24 and AD25. This makes this design unroutable and the LVDS pins will not work correctly. Please correct the design before continuing.
This was found to be an over-flow condition that occurs on larger devices.