Recovery timing errors using clock crossing bridge

Add the following to your .sdc:

set_clock_groups -asynchronous -group {clkA} -group {clkB}

where the clkA and clkB are the clocks copied right out of the timing summary. Here are some notes on that constraint:

http://www.alteraforum.com/forum/showthread.php?t=18790&highlight=set_clock_groups

SOPC Builder won't do this for you. It often doesn't know the names of the clocks(they may be coming from something outside of SOPC builder), and it can't always be certain that you want timing cut between them. For example, you may treat this interface as asynchronous, but somewhere else you might have data passed between them that is treated synchronously(of course the clocks would have to be synchronous for this to work).