Initialization Options

This section lets you reinitialize or retain the existing values of the various design objects

all

Reinitializes all the design objects.

none

Deselects all the other options.

Delete clusters

Deletes all the existing clusters and their corresponding cluster boundaries in the design because the cluster boundaries could not exist without the associated cluster.

Delete cluster boundaries

Deletes all the cluster boundaries in the design.

Delete blockages

Deletes all the blockages from the design. On selecting this option it activates Preserve blockages in the Preserve Objects section. You can use Preserve blockages to selectively preserve the placement, routing, halo, fill, pin, screen, slot and wiring blockages while deleting other blockages.

Delete wires

Deletes all existing geometric routes — vias and pathSegs. The geometric routes is basically the routing made by autorouter (Nanoroute, VCAR, VSR, or CSR) and with the Wire Editor with the option Segment in Route.

Delete rows

Deletes existing rows in the design. An existing row can either be a standard row or a custom row.

(Virtuoso Layout Suite EAD) Any existing row regions are also deleted.

Delete shapes

Deletes existing shapes in the design. On selecting this option it activates Preserve shapes in the Preserve Objects section. You can use the Preserve Objects section to selectively preserve circle, donut ellipse, path, polygon, and rectangle shapes while deleting other shapes.

Delete boundaries

Deletes the snap and area boundaries in the design. Selecting this option activates Preserve boundaries in the Preserve Objects section. You can use the Preserve boundaries field to selectively preserve the area and snap boundaries.

Delete fillers with prefix

Deletes the filler instances in the design with the filler prefix name specified in the string field next to the Delete fillers with prefix option. However, if the filler prefix is not specified in the string filed and Delete fillers with prefix is selected, a warning message is displayed. Also, if the characters such as "*" , ".*", etc. are specified in the string field, all the physical only instances in the design are deleted and a warning is displayed.

Initialize grids

Lets you initialize the grids in a design.

Initialize chip size

Creates a design boundary. On selecting this option, the Boundary Parameters section in the Reinitialize Floorplan form appears. You can create rectangle or rectilinear boundary using the options available in the Boundary Parameters section. When the design boundary gets initialized then the halo blockage associated with its PR boundary, if any, is deleted.

Also, while initializing the design boundary, if the top level PR boundary is missing and Initialize chip size is off, a warning message will be displayed.

Initialize instances

Moves all unplaced and placed instances to a position outside the PR boundary without any overlaps. Their instance placement status is reset to none. This option does not move locked and fixed instances. The instances are moved to different quadrants depending on the type of the instance master (oaCellType). Use the CIW – Tools – Set Cell Type to set the type for a big number of cells at the same time. You can also edit the Master Properties and change the cell type accordingly.

The following rules describe the position of the various instance types:

• Standard cells are placed on the right boundary of the chip.
• I/Os are placed at the upper boundary of the chip.
• Macros are placed on the left boundary of the chip.
• Custom cells are placed at the lower boundary of the chip. If there are any chained custom cells in the design, reinitialization does not break the chaining between the custom cells. However, reinitialization does not create chained custom cells.

Selecting Initialize instances activates Preserve pre-placed in the Preserve Objects section that you can use to selectively preserve the placement of I/Os, Macros, Standard cells, and Custom cells.

Initialize pins

Moves all the pins inside the PR boundary of the design and change the pin placement status to unplaced.

Preserve figGroups

Enables you to preserve figGroups present in the design. Set this option to ON if you want to preserve the figGroups and the state of the figures associated with it.

When Preserve figGroups is turned on, then the figGroups are preserved and placed at the lower boundary of the chip right adjacent to the custom cells. However, when Preserve figGroups is turned off, then all the figGroups are deleted from the design.

Preserve Objects

This section specifies the options to preserve objects.

Preserve pre-placed

Enables you to selectively preserve the locations of the pre-placed I/Os, macros, standard cells, and custom cells.

Preserve pre-placed

Enables you to selectively preserve the location of pre-placed pins, fixed pins, and locked pins. By default, fixed and locked pins are preserved.

Preserve blockages

Enables you to selectively preserve the Placement, Routing, Halo, Feedthru, Fill, Pin, Screen, and Slot blockages.

Preserve shapes

Enables you to selectively preserve the Circle, Donut, Ellipse, Path, Polygon, and/or Rectangle shapes.

Preserve boundaries

Enables you to selectively preserve the Area and/or Snap boundaries in a design.

Boundary Parameters

This section specifies the options available to modify the boundary parameters. By default, the shape of the boundary is rectangle.

Chip Origin

Specifies the point of origin of the bounding box of the rectangle’s boundary as lower left or center. The default value is lower left. If there is no PR boundary, by default, the PR boundary will be created with the lower left of the PR boundary at the origin.

Shape of Boundary

Specifies the boundary as rectangle or polygon. By default, the shape of the boundary is rectangle.

The final coordinates of the new rectangle design boundary depend on the value of Chip Origin. If you specify Chip Origin as lower left, then the lower left of the bounding box of the rectangle’s boundary should be at (0.0, 0.0). If you specify it as center, then the center of the bounding box of the rectangle boundary should be at (0.0, 0.0).

Enter Design Size

Specifies the width and height of the rectangle. On selecting Enter Design Size the Chip Width and Chip Height fields are enabled. You can use Chip Width and the Chip Height to specify the width and the height of the rectangle.

Chip Aspect Ratio (Width/Height)

Specifies the width-to-height ratio for the chip. The default value is 1.0. This option is available only when Enter Design Size is deselected.

Use Area Estimator

Specifies the area estimator to be used.

• Internal: Uses the internal area estimator PR Boundary Based or BBox Based.
• User Defined: Lets you select a registered area estimator.

Area Estimator

Selects the area estimator you want to use to estimate the area required by the chip.

Chip Area

Displays the value of the area calculated by the area estimator. You can manually specify the area in this field. The value of this field will be used to calculate the final chip width and height.