Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

Placement Planning Form (Assisted Standard Cell)

Partition lets you select a partition that was created from the Partitioning form.

Select From Layout allows you to select a partition from the layout window.

Style lets you select and load one of the available styles.

Assisted Standard Cell

Style File is used if you do not find the style you want to load then you can load a user defined style.

Browse opens the Open File form.

Load loads the file specified in the Style File field.

Load Row Template For activates the buttons and fields for the template file.

Entire Design loads the template for the entire design.

Selected Partition loads the template for the partition that you have selected.

Template File is the template file created from theDesign – Save To Template command.

Browse opens the Open File form.

Load loads the specified template file.

Region are used as boundaries within which to apply the parameters specified in the form. Once the rows are created the regions no longer exist, but you can still manipulate the rows. You can draw rows outside the region.

Region Shape determines the shape of the region.

Rectangle creates a rectangular region.

Origin X sets the X coordinate of the lower left corner of the lowest numbered row (region) being edited.

Origin Y sets the Y coordinate of the lower left corner of the row (region).

Width lets you enter the width of the row you want (larger than the height if you want horizontal rows).

Height lets you enter the height of the row you want (larger than the width if you want vertical rows).

Polygon creates a polygonal region.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

Points field appears after selecting the polygon option. Type in the coordinates, or when using the Draw option the points are updated in the Points text field.

Draw lets you use the mouse to specify the corners of a rectangle in the layout cellview.

The rectangle sets the placement region and the X, Y, Width, and Height fields are filled in with the appropriate values.

Update updates the region.

Delete removes the drawn region.

Properties are for the pins.

Allow For Pins secures a space from the boundary edge equal to the size of the pin plus the spacing rule. This prevents rows from overlapping pins.

Allow Region To Expand allows you to not decide on the size of the region. Therefore rows can grow beyond the chose region if they need to. The direction of growth is determined by the user.

Horizontally draw stretch rows in a horizontal direction.

Vertically draw stretch rows in a vertical direction.

Allow Partition To Expand applies the same concept to the partition boundary. Rows would be able to offshoot beyond the partition boundary.

Row allows you to create rows.

Row Name allows you to type a name for your row(s). If you do not specify a row name, the default row name is assigned, starting with Row1, Row2, etc.

Direction is the default direction for rows, either Vertical or Horizontal.

Utilization:

Within Row is how much of a row should be used by the components vs. how much should be left for routing. Specify either 100% Utilization or Specify %.

Between Row is how much of the region should be occupied by rows vs. how much should be left for routing channels. Specify the option Provide Row Spacing or

Specify %.

Number of Rows allows you to specify Maximum or Specify by typing in the text field the number of rows.

Standard Cell Grid is a user enforced grid.The value should not contradict the standard cell widths. The grid can be a fraction of the greatest common divisor of the standard cell widths.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

For example if you have two cells of widths 2.5 and 4.5. The GCD is 0.5 so you can choose

0.01, 0.1, 0.5, etc.

Use Filler Cells

Use Substrate Contacts

Rails allows you to specify information for power and ground pins.

Power Rail

Layer allows you to specify the layout on which the rails are drawn.

Width allows you to specify the width of the supply rails.

Net Name allows you to specify the net to which the rows belong.

Ground Rail

Layer allows you to specify the layout on which the rails are drawn.

Width allows you to specify the width of the supply rails.

Net Name allows you to specify the net to which the rows belong.

Rail Pattern pattern and spacing to conform to the standard cell style. The patterns that you can use are GP, PG, GPPG, or PGGP.

Rail Spacing spacing between power and ground rails for the same row.

Layout Generation allows you to control whether components would have to be regenerated if necessary or only missing components would be added.

Regenerate All regenerates all components.

Generate Only Missing Components generates only missing components.

Preserve Constrained Objects is used with only the Regenerate All option. The constrained objects are not deleted.

Estimates creates the rows but does not generate any layout components.

Calculate Estimates gives you an estimation of the pmos and nmos devices within a row.

Update Layout updates the current layout with the assumption that you do not want to change any of the parameters.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

Placement Planning Form (Assisted Mixed CMOS/Standard-Cell)

Partition lets you select a partition that was created from the Partitioning form.

Select From Layout allows you to select a partition from the layout window.

Style lets you select and load one of the available styles.

Assisted Standard Cell

Style File is used if you do not find the style you want to load then you can load a user defined style.

Browse opens the Open File form.

Load loads the file specified in the Style File field.

Load Row Template For activates the buttons and fields for the template file.

Entire Design loads the template for the entire design.

Selected Partition loads the template for the partition that you have selected.

Template File is the template file created from theDesign – Save To Template command.

Browse opens the Open File form.

Load loads the specified template file.

Region are used as boundaries within which to apply the parameters specified in the form. Once the rows are created the regions no longer exist, but you can still manipulate the rows. You can draw rows outside the region.

Region Shape determines the shape of the region.

Rectangle creates a rectangular region.

Origin X sets the X coordinate of the lower left corner of the lowest numbered row (region) being edited.

Origin Y sets the Y coordinate of the lower left corner of the row (region).

Width lets you enter the width of the row you want (larger than the height if you want horizontal rows).

Height lets you enter the height of the row you want (larger than the width if you want vertical rows).

Polygon creates a polygonal region.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

Points field appears after selecting the polygon option. Type in the coordinates, or when using the Draw option the points are updated in the Points text field.

Draw lets you use the mouse to specify the corners of a rectangle in the layout cellview.

The rectangle sets the placement region and the X, Y, Width, and Height fields are filled in with the appropriate values.

Update updates the region.

Delete removes the drawn region.

Properties are for the pins.

Allow For Pins secures a space from the boundary edge equal to the size of the pin plus the spacing rule. This prevents rows from overlapping pins.

Allow Region To Expand allows you to not decide on the size of the region. Therefore rows can grow beyond the chose region if they need to. The direction of growth is determined by the user.

Horizontally draw stretch rows in a horizontal direction.

Vertically draw stretch rows in a vertical direction.

Allow Partition To Expand applies the same concept to the partition boundary. Rows would be able to offshoot beyond the partition boundary.

Row allows you to create rows.

Row Name allows you to type a name for your row(s). If you do not specify a row name, the default row name is assigned, starting with Row1, Row2, etc.

Direction is the default direction for rows, either Vertical or Horizontal.

Utilization:

Within Row is how much of a row should be used by the components vs. how much should be left for routing. Specify either 100% Utilization or Specify %.

Between Row is how much of the region should be occupied by rows vs. how much should be left for routing channels. Specify the option Provide Row Spacing or

Specify %.

Number of Rows allows you to specify Maximum or Specify by typing in the text field the number of rows.

Standard Cell Grid

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

Use Filler Cells allows you to enter the names of the Filler cells you defined in the Edit

Component Type form.

Use Substrate Contacts allows you to use the component types with a component class of STDSUBCONT.

Rails allows you to specify information for power and ground pins.

Power Rail

Layer allows you to specify the layout on which the rails are drawn.

Width allows you to specify the width of the supply rails.

Net Name allows you to specify the net to which the rows belong.

Ground Rail

Layer allows you to specify the layout on which the rails are drawn.

Width allows you to specify the width of the supply rails.

Net Name allows you to specify the net to which the rows belong.

Rail Pattern specifies how N and P devices alternate between rows or how PG and GP cells alternate. The patterns that you can use are GP, PG, GPPG, or PGGP.

Position controls the relative position of rails with regard to rows. Specify either Inside,

Outside, or Center.

Row Spacing Within N-P Pair controls the distance between the N-P pair.

Minimum N-P Component specifies component spacing rule between N and P components.

Components

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

PMOS

Width Threshold is the maximum width allowed after MOS device folding is performed. The default value comes from the CDF data for the device. If the threshold value is 0, the value of the Fold Threshold option set in the Edit

Component Types form is used.

Diffusion Spacing sets the minimum spacing required between adjacent MOS chains. This value affects the estimation of the number of rows required.

NMOS

Width Threshold is the maximum width allowed after MOS device folding is performed. The default value comes from the CDF data for the device.

Diffusion Spacing sets the minimum spacing required between adjacent MOS chains. This value affects the estimation of the number of rows required.

Align Components controls the relative alignment of devices in adjacent rows.

Inside aligns the P and N devices that are aligned toward each other.

Outside alignment aligns the devices away from each other.

Center aligns the devices with the row center line.

PMOS Offset to Row Edge is the distance between the edge of the devices that is closer to row edge and the edge of the row.

NMOS Offset To Row Edge is the distance between the edge of the devices that is closer to row edge and the edge of the row.

Allow Chaining determines that components will be chained.

Stack Partition Parameter sets the device stacking partition parameters.

Max Chain Size sets the maximum number of devices in stack.

Layout Generation allows you to control whether components would have to be regenerated if necessary or only missing components would be added.

Regenerate All regenerates all components.

Generate Only Missing Components generates only missing components.

Preserve Constrained Objects is used with only the Regenerate All option. The constrained objects are not deleted.

Estimates creates the rows but does not generate any layout components.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

Calculate Estimates gives you an estimation of the pmos and nmos devices within a row.

Update Layout updates the current layout with the assumption that you do not want to change any of the parameters.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

Placement Planning Form (Manual User-Defined)

Partition lets you select a partition that was created from the Partitioning form.

Select From Layout allows you to select a partition from the layout window.

Style lets you select and load one of the available styles.

Manual User-Defined

Style File is used if you do not find the style you want to load then you can load a user defined style.

Browse opens the Open File form.

Load loads the file specified in theStyle File field.

Load Row Template For activates the buttons and fields for the template file.

Entire Design loads the template for the entire design.

Selected Partition loads the template for the partition that you have selected.

Template File is the template file created from theDesign – Save To Template command.

Browse opens the Open File form.

Load loads the specified template file.

General

Row Name allows you to type a name for your row(s). If you do not specify a row name, the default row name is assigned, starting with Row1, Row2, etc.

Direction is the default direction for rows, either Vertical or Horizontal.

Initialize First Row

Draw lets you use the mouse to specify the corners of a rectangle in the layout cellview. The rectangle sets the placement region and the X, Y, Width, and Height

fields are filled in with the appropriate values.

Spacing Between Rows is how much of the region should be occupied by rows vs. how much should be left for routing channels.

Number of Rows to Create is the total number of rows in the list box.

Types

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

Create allows you to change the options from Component Grid on down to create the component type.

Update allows you to select the component type in the Types field and change any of the attributes.

Edit opens the Choose Component Types form. Select an existing component type and click OK.

Component Type(s) the component type that you selected in the Choose Component Types form appears in this field.

Component Grid defines the component grid for the row(s).

Reference Point For Type allows you to set a reference point for a component type to be either Top, Center, Bottom, Origin.

Reference Point For Row allows you to set a reference point for a row to be either Top,

Center, or Bottom.

Type “Top” Offset From Row “Top” is the distance between the reference on the row and the reference on the component.

Allowed Orientations are R0, MY, R90, MXR90, MX, R180, MYR90, R270, AS IS

Rails

Rails allows you to create a user-defined rail using theLayer, Width, and Net Name options.

Add allows you to add the user-defined rail to theRails field.

Update allows you to update the Layer, Width, and Net Name for the selected rail.

Delete allows you to delete the selected rail.

Layer is the layer of the rail.

Width is the width of the rail.

Net Name is the name of the rail.

Reference Point For Rail allows you to set a reference point for the rail to be either

Top, Center, or Bottom.

Reference Point For Row allows you to set a reference point for a row to be either Top,

Center, or Bottom

Type “Top” Offset From Row “Top” is the distance between the reference on the row and the reference on the rail.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

Sort By allows you to sort the rows using different sorting filters which areName, Inc. X,

Inc. Y, Inc X, Dec. Y, Dec X, Inc Y, Dec. X, Dec. Y.

Number of Rows is the number of rows generated after running Calculate Estimates.

Search allows you to search for rows.

Choose From Layout allows you to select a row in the layout and have the row be highlighted in the list box.

Select All selects all rows in the list box.

Deselect All deselects all selected rows in the list box.

Create New creates new rows.

Update Selected changes any of the properties of the selected row that you have just changed.

Delete Selected allows you to delete any selected row.

Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer