Synchronizer XDC constraint

What this Xilinx XDC synchronizer constraint question tests

This is an easy SystemVerilog and FPGA design question that evaluates your understanding of clock-domain crossing (CDC) synchronization and how to express timing constraints in Xilinx Design Constraint (XDC) files. It probes whether you can recognize a synchronizer circuit and apply the correct constraint to prevent false timing violations.

In real FPGA designs, data often moves between independent clock domains. Synchronizers—typically chains of flip-flops—safely transfer signals across these boundaries by allowing extra time for metastability to resolve. The key skill here is identifying when a CDC path exists and knowing which XDC constraint tells the place-and-route tool to relax (or disable) the normal timing check on that path, rather than forcing it to meet a standard clock-to-clock relationship.

• Clock-domain crossing detection and design patterns
• Metastability and synchronizer design
• XDC false-path and set_max_delay directives
• Timing constraint philosophy for intentionally slow paths