In the synchronizer option, the output signal from the truth table is clocked through a two-stage synchronizer, and the signal will be delayed up to two clock cycles when using this option. A glitch from the LUT shorter than one clock cycle will be filtered out using the synchronizer as long as the glitch is not present on the rising edge of the clock. Although useful in many situations, the two-stage synchronizer has limitations. If the glitch is present on the rising edge on the first stage of the synchronizer, it will latch and the glitch will become one clock cycle long when exiting the synchronizer.
Figure 1. Two-stage Synchronizer
Figure 2. Two-stage Synchronizer
Timing
