AR# 1313: Why does Flow Engine run the XBLOX program on my non-XBLOX design?
Why does Flow Engine run the XBLOX program on my non-XBLOX design?
You may notice that XBLOX is being run on your design even though your design does not contain XBLOX components.
The XBLOX program does more than just synthesize XBLOX modules into gate-level logic; it is also called to perform certain architectural optimizations, including those associated with the following options in the Implementation template, Optimization panel:
Merge Flip-Flops Into I/Os Use Global Resources for High Fan-out Signals
If you do not want XBLOX to be run (to shorten compilation time), then deselect the aformentioned options. Be warned that this may result in a sub-optimal design.