I have to make changes to an old legacy product containing an XC4005 part. I was able to find a set of old XACT tools but the problem is that the newer synplify versions infer the primitives IDFX and ODFX. These to primitives are NOT included in the XC4000 libriaries and I have not been been able to get past the xnfmerge step. I looked at the xnf file and the ODFX and IDFX primitives are D-Flip-flops with enable. But when I look at the logic there is no enable needed. Syplicity ties the enable to VCC. For example, the following proccess,
PROCESS(clk27m) BEGIN IF RISING_EDGE(clk27m) THEN d1data