5611 - MachXO3 : How do designer deal with Metastability?
Metastability can occur in a number of asynchronous systems, usually due to the inability to guarantee that the setup time of the flip-flops will be satisfied. In standard synchronous systems where the setup time (and all other timing requirements) is specifically designed in, metastability will never be a problem. In some situations, metastability is caused by the need to interface systems with different clocks. In this case, it will never be possible to completely eliminate the possibility of metastability. Instead, the designer must take steps to reduce the probability of system failure due to metastability.
For more information you can check Application Note: AN8060 (link: https://www.latticesemi.com/view_document?document_id=1162)