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.
-auto_incremental Option
This enables the automatic incremental flow described in Automatic Incremental.
-fix_objects Option
-fix_objects <cell objects>
The -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.
Examples
The following are examples of the -fix_objects
usage:
- To reuse all objects and fix only Block Memory
placement:
read_checkpoint -incremental routed.dcp -fix_objects [all_rams]
- To reuse all objects and fix only DSP
placement:
read_checkpoint -incremental routed.dcp -fix_objects [all_dsps]
-force_incr Option
The-force_incr
option can be used to
force the incremental implementation flow irrespective of the incremental criteria
checks. When not specified the incremental implementation flow may exit and continue
in non-incremental or default flow.
This option can be used instead of modifying the incremental implementation configurations values to update the minimum thresholds for cell matching, net matching, and WNS in the automatic incremental flow.
-force_incr
is only used along with the -incremental switch.