Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

If you specify spacing between a pin and an iterated pin, the software applies the space between the last pin of the iterated pin and the individual pin.

5.Click Apply.

The pin moves to the position specified.

Pitch values are only enforced if two pins are adjacent on an edge, even if spacing is set between two non-adjacent pins.

You will receive a warning in the CIW if the pitch for the pins cannot be satisfied. Also notice that the pins have not moved.

Saving Pin Placement to a Template File

To save the pin location and constraint information to a template file use theDesign – Save To Template command.

You can save the following information from the pin placement form:

Pin location

Floating

Fixed at placed location

As Is

Constraint

The boundary edge on which a pin is placed

The order in which a pin has been placed on an edge boundary.

If the pin is fixed to a certain location

The required distance between a pin and its neighboring pins.

Pins that are either vertical or horizontal rails.

Partitioning the Design

To plan the layout more efficiently you can cluster components together and assign them specific area of the layout. This allows you to monitor the placement more closely.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

You use the Place – Partitioning command to assign components to a partition. A partition defines an area in the design to which you can confine components.

■All legal placements have to be made inside the design boundary

■The design boundary is the default partition

If no partition exists, all the components belong to the design boundary.

If a component is not assigned to any partition, it belongs to the design boundary.

If no partition is selected, the design boundary becomes the target partition

the keyword “boundary” is a reserved name that cannot be used as a partition name

■A component that is not assigned to that partition should not be placed in that partition

■A partition can be created without having a shape giving you the ability to partition a netlist or schematic.

■Partitions can be made in terms of the connectivity source name space or the layout name space

■All members of a one-to-many, many-to-one, or many-to-many group will have to be assigned to the same partition.

Important

To view any ECO changes in the Partitioning form you must close and then re-open the Partitioning form.

Creating a Partition

1.Create a shape that will be attached to the partition. In the LSW select Edit – Set Valid layers and add the softFence drawing layer purpose pair to the list of Valid layers.

Note: The sequence of creating a partition and a shape does not matter.

2.Select Create – Rectangle and draw a rectangle on the softFence layer around the devices that you want to keep together during placement.

3.To create a partition select Place – Partitioning.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

4. The Partitioning form appears.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

5.Click Link and then click anywhere in the layout cellview to link the Partitioning form to the layout.In the CIW a message appears telling you that the Partitioning Form is linked to the design “VCPLIB BUF layout”.

6.By default the Partition name is set to Boundary. To create a new partition name clear the text field and type in a user defined partition name and selectCreate Partition.

The new partition name appears in the cyclic field with a question mark next to the name. The question mark denotes that the partition does not have a shape attached to it.

7.To attach the softFence rectangle to the partition select Attach Shape and click to select the rectangle.

8.To add the devices to the partition change the Target Partition to the new partition name and select the devices in the Component Name list.

9.Select Move to move the devices into the partition. Notice that the components and partition are highlighted.

Loading the Template File

1.Click on the Browse button and the Open File form appears.

If you know the template file name you can type the file name in theTemplate text field.

2.Click on the directories in the left list box to descend into your file hierarchy until you reach the name of the template file to use.

The left and right arrows at the right side of the form let you go up and down in the file hierarchy.

3.Click on the name of the template file in the right list box to enter it in theName field.

4.Click OK.

Saving Partitions to a Template File

You can save the partition information from the cellview to a template file by using theDesign

– Save To Template command. Below is an example of the partition information that is saved to the template file.

partition_section(

connectivity "VCPLIB DFF schematic"