In reply to srikanth.verification:
I am not sure I understand your question correctly. Can you elaborate it more? I believe, that when you see 100% coverage, that you do not find missing RTL or any error at this point of view. Because if there is an error, it was made in previous step during creation of the cover points.
Lets suppose you are verifying simple CPU. You start with the requirements document, which specifies instruction set of the CPU. Therefore you define cover point for every instruction in every mode that is defined. Then you implement verification and obtain 100% functional coverage. This means that you tests all coverpoints. If there is some block of code that is missing from your RTL, that means that the functionality it implements is missing from functional coverage as well. Which means that it is also missing from the requirement document
or that there was mistake during definition of functional cover point and your functional coverage is meaningless (because you obviously are missing parts of requirements). To detect this mistake, you should have trace matrix that will link all your cover points to the requirements and you should always perform peer review of the cover points.
There is second thred with similar question, maybe their answers will be more clear :