If no command arguments (other than -incremental) are specified, the tool reuses as
much of the reference checkpoint information that it can. However, command arguments
can be applied to the
read_checkpoint -incremental command that
give the user control over what is used and not reused.
This enables the automatic incremental flow described in Automatic Incremental.
-fix_objects <cell objects>
-fix_objects option can be used to lock a subset of cells. These
cells are not touched by the incremental place and route tools. The
-fix_objects option only works on cells that match and are
identified for cell reuse. This is the full design space when
-reuse_objects is not specified, or the associated cells when
-reuse_objects is specified.
The following are examples of their use:
- To reuse all objects and fix only Block Memory
read_checkpoint -incremental routed.dcp -fix_objects [all_rams]
- To reuse all objects and fix only DSP
read_checkpoint -incremental routed.dcp -fix_objects [all_dsps]