6.1.1 Block Features

You can synthesize, simulate, and place and route a block as a regular design. You can lock the place and route of the block to ensure repeatable performance. Performance and place and route of a block can be fixed. However, these rules can be relaxed, if necessary, to ensure that you can integrate the block into the top-level project.

Use blocks when you:

• Have multiple team members working on different parts of the same design.
• Have a crowded design that uses 90% or more of the resources on a given die.
• Have difficulty in meeting timing as working on the entire design. Blocks allow you to compartmentalize and optimize design sections before optimizing the entire design.
• Want to re-use elements of the design.
• Want to make minor changes to the design and expect to keep the remaining design unchanged with ensured performance.

Blocks are family- and die-specific, and cannot be used with all families. If your block has I/Os, it is also package-specific.