In reply to Gokul S:
There are 2 stages when you can achieve 100% functional coverage:
- Too early — you haven't collected enough requirements to cover (testing a multiplier by multiplying
- Too late — you have to many requirements to cover, many of them redundant.
Achieving 100% functional coverage is the Holy Grail of Verification. Whether you run one test or many individual runs and merge the coverage results together depends on your design and its requirements. It's better to distribute your tests into multiple runs for better throughput.