Achronix ACE Version 5.0 - Manual (Page 311)

Placement Regions and Placement Region Constraints Chapter 4. Tasks
4. (Optional) If the Placement Region is meant to align with (snap to) one or more Clock Regions , enable
the overlay for those regions from the Clock Regions view . This will not affect the functionality during
the resize in any way, but will make it easier to know where to define the region bounds.
5. Move the mouse over the placement region to be moved. The mouse pointer will change to a move
cursor when the mouse is over any placement region.
6. Press and hold the left mouse button and drag the mouse to the desired new location for the placement
region.
7. Release the left mouse button when the mouse is at the desired location.
8. ACE calculates the enclosed subtile grid coordinates, growing as necessary to ensure all partially-
enclosed subtiles (or Clock Regions) are fully enclosed.
9. The Placement Region View’s table content is updated to show the new site counts enclosed by the
Placement Region, and the Floorplanner is updated to show the Placement Region overlay at the new
location (and with the latest dimensions).
Assigning placement region constraints
Placement Region Constraints may only be assigned to Core Instances. You may specify the list of Core
Instances to constrain explicitly as a list of individual instances, or by specifying a Clock Domain name or
Critical Path ID.
If a Critical Path is assigned, ACE determines which Core Instances are part of that Critical Path, and
assigns the Placement Region Constraint to those Instances. Likewise, if a Clock Domain is assigned,
ACE determines which Core Instances are part of that Clock Domain, and assigns the Placement Region
Constraint to all of those Core Instances.
Saving Critical Path or
Clock Domain
Constraints:
When Critical Paths or Clock Domains are used to specify the constraint,
they are immediately expanded into a list of the corresponding Core
Instances within ACE. If the placement region constraints are exported
from ACE (saved in a pdc file), they are saved as explicit lists of instances,
and the original association with a Critical Path or Clock Domain is lost.
Users may want to create more-concise constraints for their design by
manually entering the placement region constraint in the PDC file using
the clock domain name instead of the list of explicit instances.
If any Instance which was previously assigned a placement region constraint is assigned a new placement
region, the prior constraint is overridden/discarded.
Instances from the IO Ring are never added to a placement region constraint. Constants (sources/sinks)
and boundary elements (SACs/ASCs) are not added to a placement region constraint by default either.
Optionally, placement region constraints may be restricted to allow only flops; all other instances will
be excluded. (Setting these inclusion/exclusion preferences for mouse actions is done on the
Placement
Regions Preference Page .)
Instances may be assigned placement region constraints from the Tcl console with add region insts , or
with drag-and-drop mouse actions in the ACE GUI.
Mouse drag-assign actions can start from:
• the Search view, where individual Instances and/or Paths, groups of Instances and/or Paths, or all
Instances and/or Paths in the search results (if the titled branch nodes themselves are dragged, even
the Instances/Paths not in the current set of 200 on the visible page of results) may be drag-assigned.
• the Selection view, where individual Instances and/or Paths, groups of Instances and/or Paths, or all
Instances and/or Paths in the selection set (if the titled branch nodes themselves are dragged, even
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