How to solve the following error in Xilinx ISE :
"Simulator:702 - Can not find design unit xxx in library work located at isim/work"
You can try two methods to solve this error:
1) Go to main menu -> Project -> Cleanup Project files. Click 'ok'. Now run the simulation again. If the error is still on then go to step 2.
Note:-Cleaning up project files removes the generated synthesis and implementation files from the current project directory.This operation is final and you can not undo this procedure after you perform it.If you want to avoid loss of data, then create a backup copy of the project.For creating a back up for your project :
Select Project > Take Snapshot.
In the Take a Snapshot of the Project dialog box, enter a name for your snapshot in the Snapshot Name field.
In the Comment field, add any notes related to this version of your project. Comments are optional.
2)Create a new project and add all the files in your current project to the new project.Now simulate the design.It should work now.