How can one designer manage the crossing of data from one clock domain to other clock domain?
Clock Domain Crossing (CDC) Tips
- Eliminate the combinatorial paths between two clock domains when signal is transferred from one clock domain to another clock domain.
- FFs forming the synchronizer circuits must be placed closed to each other to allow smallest possible clock skew between them.
How are clocks synchronized?
HOW DOES IT WORK? In a synchronized clock system, the master clock receives time from either an NTP server or GPS receiver, or its internal clock can be utilized as a time source. When the master clock has received the correct time from either source, the time is then distributed to all slave clocks in the system.
Do you need to design clock domain crossing correctly?
Clock domain crossing (CDC) logic bugs are elusive and extremely difficult to debug, so it is imperative to design synchronization logic correctly from the start! Passing a single control signal across a clock domain crossing (CDC) isn’t very exciting.
How is clock domain crossing ( CDC ) analysis done?
Approaching CDC analysis of this system requires a systematic methodology. In flat SoC verification, the entire SoC is verified in a single run.
What causes synchronization failure in clock domain crossing?
Synchronization failure occurs when the output of the destination flip-flop goes metastable and does not converge to a legal state by the time its output must be sampled again (by the next flip-flop in the destination domain). Worse yet, that next flip-flop may also go metastable, causing metastability to propagate through the design!
Can you cross clock domains in an FPGA?
Crossing clock domains inside of an FPGA is a common task, but it is one that many digital designers have trouble with. Problems can occur if the digital designer does not understand all of the details involved in crossing from one clock domain into another. A single clock domain entails all of the Flip-Flops that are driven by one clock.