can LEC provide cdc check?

 1. I dont think Lec can extract the clock automatically. I dont know to be sure (I havent been using Lec long) but the documentation seems to suggest that you have to specify yourself using the 'ADD CLOCK' or 'READ SDC' commands. 

2. I think you misunderstand what I have said. This is the bit I spent a long time being confused over. You cannot verify your design in the 'categorization' flow. It is to give you an idea of what sort of synchronizers are in your design. To properly validate it you need to be in the normal flow which as far as I understand means you need to add synchronization rules for the synchronizers you allow in your design. Below is the email reply I got from Cadence support. (it might make sense or it might not :)

 "When you run the tool with predefined rules it is more to have a categorization of the type of synchronization you have in your design.It is not the normal flow. The categorization flow is just there to have an idea of the design. The regular flow is when you define your add sync rule. Thus you need to define your synchronization rule before you run the structural check. And functional checks cannot be run without structural checks. The difference can be seen if you look at the FAIL category in the categorization flow. Had it been the normal validation flow these would have shown up under the "fail" column of report validated data."

You can just add the same rules if you want using the 'add synchronizer rule' command and specifying the right options.

 3.  Good Question! Depends on the design I believe. Since there are all the options I guess they are all meant to be used. I have been using: -derived -logic_nophase -conflict_error -noextract

Make sure you know what each option does and choose the one suited to your design. It is best to check the domains afterwards anyway. I had to add some together that were separate. Check out this. It might help although the user guide is pretty good for describing things: http://www.cadence.com/india/newsletters/icon_2006_03.pdf  - the technowatch bit.

I'm still quite new to Lec and only started looking at it a couple of months ago but this is what I believe is correct 

 Tim

 1. I dont think Lec can extract the clock automatically. I dont know to be sure (I havent been using Lec long) but the documentation seems to suggest that you have to specify yourself using the 'ADD CLOCK' or 'READ SDC' commands. 

2. I think you misunderstand what I have said. This is the bit I spent a long time being confused over. You cannot verify your design in the 'categorization' flow. It is to give you an idea of what sort of synchronizers are in your design. To properly validate it you need to be in the normal flow which as far as I understand means you need to add synchronization rules for the synchronizers you allow in your design. Below is the email reply I got from Cadence support. (it might make sense or it might not :)

 "When you run the tool with predefined rules it is more to have a categorization of the type of synchronization you have in your design.It is not the normal flow. The categorization flow is just there to have an idea of the design. The regular flow is when you define your add sync rule. Thus you need to define your synchronization rule before you run the structural check. And functional checks cannot be run without structural checks. The difference can be seen if you look at the FAIL category in the categorization flow. Had it been the normal validation flow these would have shown up under the "fail" column of report validated data."

You can just add the same rules if you want using the 'add synchronizer rule' command and specifying the right options.

 3.  Good Question! Depends on the design I believe. Since there are all the options I guess they are all meant to be used. I have been using: -derived -logic_nophase -conflict_error -noextract

Make sure you know what each option does and choose the one suited to your design. It is best to check the domains afterwards anyway. I had to add some together that were separate. Check out this. It might help although the user guide is pretty good for describing things: http://www.cadence.com/india/newsletters/icon_2006_03.pdf  - the technowatch bit.

I'm still quite new to Lec and only started looking at it a couple of months ago but this is what I believe is correct 

 Tim