There is a old IP which used many rising edge and falling edge clock, now it's should be inserted with scan, I want to use the mux to replace all the rising edge clock for falling edge functional clock when on scan mode, and connect all flip-flop together for a high coverage, is it any potential problem about this?
Thanks in advance
Most if not all scan insertion tools will automatically put the negedge flops before the posedge flops in the scan path - but of course, there's nothing the tool can do about scan capture mode, where you still may have negedge flops capturing posedge flop data. So you will lose some fault coverage here, because the negedge flops will always capture 'new' data (the same data that the posedge flop just latched in). To remedy this, you can, if you wish, invert the clocks to the negedge flops during scan mode, but then you're messing with your clock tree, and you don't always want to do that...