Routing Assistant User Interface for Device-Level Routing

The Routing assistant is a simplified, consistent, flow-based assistant for all design types. It has the same look and feel for device, standard cell and chip assembly routing with a common toolbar for all routing types. The Routing assistant is a dockable assistant pane that provides various options to let you perform tasks related to advanced routing technology.

The Routing assistant lets you:

Select the routing mode and design type
Load and save routing options
Manage the routing flow through dedicated tabs
- Lets you define the scope and options for each task and specifying the output
- Lets you set up, run pre-routing checks, power grid generation, routing, and view results
- Provides access to a Routing Results Browser
Display alerts and other information about the width spacing patterns you are creating and updating
Access the unified Routing Constraint Manager

The Routing Assistant has the following components:

Routing Assistant Toolbar	Lets you access the buttons to complete the steps of the routing flow.
Routing Assistant Tabs	Lets you specify the options for running the selected routing type.
Routing Assistant Command Buttons	Lets you access the buttons on each tab to compete a routing task.

Routing Assistant Toolbar

The following table lists the functions of the different buttons on the Routing assistant toolbar:

Icon	Command	Description
	Change routing mode	Selects the routing mode. The two routing modes are Automatic and Interactive.
	Change routing type	Changes the type of routing you want to run on the design. The three routing types are: Device, StdCell, Chip Assembly.
	Raise the pre-routing browser	Opens the pre-routing browser and provides net information prior to routing.
	Set router constraints	Opens the Routing Constraint Manager
	Load preset options	Lets you load options from an existing preset file.
	Save preset options	Lets you save the preset options to a file.
	Delete preset options	Lets you delete any existing preset options.

Routing Assistant Tabs

The following table lists the functions of the different tabs in the Routing assistant:

Tab	Description
Setup	Lets you specify the settings and generate or import WSPs for running the router.
Check	Lets you select the checks that you want to run before routing the design.
Supply	Lets you run the power router. You need to have power and ground wireType tracks in your width spacing patterns. Usually, you run this routing before placement.
Route	Lets you specify the scope and run routing on signal nets.
Results	Lets you select the scope and the results columns that should be displayed in Routing Results Browser.

The options in the Routing Assistant depend on the routing type in which the design is open. These routing types are:

Device-level This routing flow help users to get familiar with the device-level placement and routing solution in Virtuoso for advanced-node, with the focus on uniform designs.
Standard Cell This routing technology seamlessly integrates the NanoRoute router in the Virtuoso environment. It provides different ways for you to generate WSPs as well as route without them, relying on Innovus created tracks.
Chip Assembly This routing technology is meant for routing a top-level design that has macro instances, I/O pads, and can also contain stdcell areas. It also addresses memory type designs using Spine routing.

Setup

The following table describes the fields available on the Setup tab of the Routing assistant for device-level routing type.

Field	Description
*Options*
Insert trim to fix DRCs	Inserts trim shapes in the design to fix DRC errors. Environment variable: setup_insertTrim
Check DRCs after routing	Controls whether to automatically runs DRD design rule checks after routing. Environment variable: setup_checkDRCsAfterRouting
Lock Colors after routing	Controls whether to automatically lock colored shapes after routing. This option is currently grayed and unavailable for use. Environment variable: setup_lockColorsAfterRouting
*Extraction Options*	Lets you specify the layers for which to generate WSPs.
Extracted Pin Style	Lets you specify the pin extraction style before routing. The available options are: Labeled shapes only Connected shapes on same layer Whole net on routing layers
*Layer Settings*	Lets you specify the layers for which to generate WSPs.
Wire CG	Specifies the constraint group used to supply a default set of constraints for routing modes. The default constraint group is `virtuosoDefaultSetup`.
Routing Layers	Specifies valid bottom and top layers for routing.
Wire Types Map	Opens a form with a table that maps the wireType to the symbol to be used in the pattern specification in the table.
Wire Types Assign to nets	Opens a form with a table that assigns wireTypes to nets.
*Layer table*	Provides a list of layers on which WSPs are generated.
Layer	The name of the layer.
Pattern	Generates the pattern of WSP as per your requirement. For example, `gs3ns2g3` where `g` stands for ground, `s` for signal, `n` for Null, and `p` for power.
Dir	The routing direction of the layer. The supported routing directions include Horizontal, Vertical, Orthogonal, and Forbid. Forbid implies that no direction is considered.
W	The width specified for the layer.
S	The spacing specified for the layer.
WSP	The width spacing patterns defined for the layer. All available WSPs are displayed in the WSP drop-down list. If any WSP pattern for a layer is not available in the Track Pattern Assistant, then the WSP drop-down appears blank. When you select a WSP from the drop-down list in the Setup tab of the Routing assistant, the WSP is active in the Track Pattern Assistant. If you make any WSP pattern active in the Track Pattern Assistant, it is displayed as an active option in the WSP drop-down list in the Setup tab of the Routing assistant.

Check

The following table describes the fields available on the Check tab of the Routing assistant for device-level routing type.

Field	Description
*Check*	Provides a list of checks that can be run for the routing type.
Select	Lets you specify the checks to be run. Click All or None to select or deselect all checks with a single click.
Routing Track Availability	Checks for the availability of routing tracks on a metal layer.
Pin WSP Conformance	Checks for the misalignment between metal layer pins and WSP tracks in terms of color, width, and alignment.
Track Spacing	Checks if the track spacing is DRC correct.
Via Availability & Density	Checks for congestion or limitations for via placement and track density.
Device Trims	Checks for insufficient space for DRC clean trim insertion.
Net Pin Symmetry	Checks the symmetrical nets pin placement.
Normal Pin Access	Checks if the metal layer pins are accessible and not dead or blocked.
Gate Pin Access	Checks for misalignment between WSP tracks and gate pins.
S/D Pin Overlaps	Checks for the misalignment of WSP tracks with source and drain pins.
Diffusion Pin Nets	Checks the mismatch between diffusion pin nets on device and top-level nets.
Trim Insertion Validity	Reruns the trim engine deleting and replacing the existing trims such that there are no trim related violations. This option is available only in certain advanced node flows.
Existing DRCs	Specifies whether to run design rule checks for DRD. Environment variable: check_existingDRCs
*Output*	Settings to display the output of routing checks.
Display Log	Controls the display of the checker log in the CIW once the checks are run. Environment variable: check_displayLog
Overwrite last log	Controls the overwriting of the last log file. When the option is deselected, the existing log file is retained. Environment variable: check_overwriteLog
Markers	Controls the generation of markers for errors. These error markers can be viewed in the Misc tab of the Annotation Browser. Environment variable: check_generateMarkers

Supply

The following table describes the fields available on the Supply tab of the Routing assistant for device-level routing type.

Field	Description
*Scope*	Defines the scope of supply routing.
Supply Nets	Specifies whether to route all or selected supply nets. Environment variable: supply_nets
Within	Specifies whether to route everything inside the PR boundary or only within a guard ring or figGroup, or specify an area. You can also create supply stripes inside a row region or wsp region. The available options are: PR boundary, Guardring/FigGroup, Area, and WSP/Row. Environment variable: supply_netsWithin
*Options*
Only use layers with WSP P/G tracks	Restricts supply routing to layers with existing power or ground tracks. However, when unselected, allows all routing layers to be used.
Supply stripes	Lets you select the bottom and the top metal layers for routing. Environment variable: supply_deleteStripes
Generate supply stripes	Generates stripes when supply routing is run. Environment variable: supply_genSupplyStripes
Insert vias for supply stripes	Inserts the vias between the intersection of the layer above and below the via. Environment variable: supply_insertVias
Connect to overlapped terminals and guardrings	Specifies whether or not the supply router should connect to instance terminal pins and guard rings. Environment variable: supply_connectToTermAndGR
Share tracks for supply nets	Determines whether or not the supply nets should share power and ground tracks as needed in the appropriate P and N regions. Environment variable: supply_shareTracks
Create only on P/N regions	Determines whether or not to only route inside Pch or Nch region or not under shared track mode. Environment variable: supply_createOnPNRegions
Create supply grid as a group	Specifies to create the supply grid as a figGroup. Environment variable: supply_createGridAsGroup
Ignore boundary tracks	Creates power stripes on tracks that are coincident with the PR boundary. When set to `t`, no power stripes (or power vias) are created coincident to the PR Boundary edge.
Ignore boundary vias	Creates power vias on tracks that are coincident with the PR boundary. When set to `t`, no power stripes (or power vias) are created coincident to the PR Boundary edge.
Assign to nets	Opens a form with a table that assigns wireTypes to nets.
Pull-back	Controls the spacing of power nets per layer from the PR boundary to avoid any DRC.
*Pins*	Lets you specify the pin related options for routing.
Create	Specifies to create a pin instead of a pathSeg for the stripe. Environment variable: supply_createPins
Create label	Creates labels on the pins.
Use all supply stripes layer	Creates pins on all supply stripe layers.
Use selected layers	Creates pins on selected supply stripe layers.
Create on ends	Creates pins only on the ends of the supply stripes.
Create on pin purpose	Enables to use pin as the layer purpose for the created pin. Environment variable: supply_createPinsOnPinPurpose
*Update*
Delete Supply stripes	Deletes the stripes generated by the supply router before power routing. Environment variable: supply_deleteStripes
Delete Supply vias	Deletes the vias generated by the supply router before power routing. Environment variable: supply_deleteVias
*Output*
Display log	Controls the display of the log in the CIW when supply routing is run. Environment variable: supply_displayLog
Overwrite last log	Specifies whether to overwrite the last log file or keep the existing one. When the option is selected, the existing log is overwritten. Environment variable: supply_overwriteLog
Current cellview	Write the output of the supply routing to the current cellview. Environment variable: supply_routedLoc
Other cellview	Lets you select a view name to write the output of the supply routing to another cellview. You can also specify a non-database existing name. The name of the cell is `$cell_proute` with `_proute` as the postfix to the cell name. The view name is always layout. Environment variable: supply_defaultRoutedView, supply_routedLoc, supply_defaultRoutedCellExpression
Save routing only	Specifies whether to copy only the supply grid or all initial data and the supply grid to the new cellview. Environment variable: supply_saveRoutingOnly

Route

The following table describes the fields available on the Route tab of the Routing assistant for device-level routing type.

Field	Description
*Scope*	Defines the scope of signal routing.
Nets	Specifies whether you want to route all nets, selected nets, or only nets with opens or shorts when the routing option is selected as Auto. When the routing options is selected as Assisted, the scope is Selected only, which allows routing of a single net at a time. Environment variable: route_nets
Include supply nets	Includes the power and ground nets for routing. This option is only available when the routing option is selected as Auto.
Within	Specifies whether to route everything inside the PR boundary, within a specified area, or within a device array or figGroup. Environment variable: route_netsWithin
*Routing Options*	Lets you specify the routing options for automatic and assisted routing.
*Auto*	When selected, lets you specify the options for automatic routing.
Optimize Wire length	Optimizes the wire length during routing.
Optimize Vias	Optimizes the via count during routing.
Connect on both sides of gate	Connects to both vias if there are two poly connections (vias).
Prefer finishing over constraints	Routes the larger sized nets first over constraint nets so that convergence is given preference over constraints.
Prefer finishing over DRC clean
Preferred Range	Lets you specify the preferred bottom and top layers to be routed.
Update pins for optimized routing
*Assisted*	Lets you specify the routing options for assisted routing.
Enable hierarchical trims	Enables trim insertion in hierarchical designs. This option is available only in certain advanced node flows. Environment variable: route_enableHierarchicalTrims
Minimize M0 on nets	Minimizes the capacitance on M0 nets in addition to the regular trim insertion. This option is available only in certain advanced node flows. Environment variable: route_minimizeM0OnNets
Insert M0 trims	Inserts M0 trim shapes to fix shorts. This option is available only in certain advanced node flows.
Delete M0 trims	Deletes all M0 trim shapes. This option is available only in certain advanced node flows.
*General*
Preferred range	Lets you specify the bottom and top layers to be routed.
Finish routing	Lets you run finish routing on the preferred range of layers.
*Mesh*
Mesh layers	Lets you specify the bottom and top layers to be routed in the mesh.
Extend preroutes for mesh	Lets you select whether or not to extend pre-routes to active meshing layer. Environment variable: route_meshExtendPreroutes
Generate mesh routing	Lets you create mesh on the specified layers of the selected nets within the specified scope.
*P2T*
Trunk layer	Lets you specify the bottom and top layers to be routed in pin to trunk routing.
Create trunks	Creates trunks for the selected or all nets in the design. Environment variable: route_createTrunks
Connect instances to trunks	Connects pins of devices and macro instances to existing trunks. Environment variable: route_connectInstsToTrunks
Generate P2T routing	Lets you run the Pin to Trunk routing on the specified scope either on all the nets or selected nets.
*Update*
Delete Select	Lets you select either all or no options for deletion. You can also select specific options.
Wires and vias	Deletes the wires and vias created by the router. Environment variable: route_deleteWiresAndVias
Trunks	Deletes the routed trunks. Environment variable: route_deleteTrunks
Manual routing	Deletes the manually routed wires and vias. Environment variable: route_deleteManualRouting
*Output*
Display log	Controls the display of the log in the CIW when signal routing is run. Environment variable: route_displayLog
Overview last log	Specifies whether to overwrite the last log file or keep the existing one. When the option is selected, the existing log is overwritten. Environment variable: route_overwriteLog
Current cellview	Writes the output of the supply routing to the current cellview. Environment variable: route_defaultRoutedView
Other cellview	Lets you specify a view name to write the output of the signal routing to another cellview. Environment variable: route_defaultRoutedView
Save routing only	Specifies whether to copy only the supply grid or all initial data and the supply grid to the new cellview. Environment variable: route_saveRoutingOnly
Create routing as a group	Specifies whether or not to create routing as a figGroup. Environment variable: route_createRoutingAsAGroup

Results

The following table describes the fields available on the Results tab of the Routing assistant for device-level routing type.

Field	Description
*Scope*	Defines the scope of the routing results.
Nets	Specifies whether you want to show the routing result of all nets, selected nets, or only nets with opens. Environment variable: results_nets
Supply Nets	Shows the routing result of power and ground nets. Environment variable: results_supplyNets
Within	Specifies whether you want to show the routing result of nets inside the PR boundary or within a device array or figGroup. Environment variable: route_netsWithin
*Summary of latest run*	Displays the summary of the routing results for various parameters, such as Time, Instances, Nets, DRCs, Opens, Shorts, Wire Length, Vias.
*Output*	Specifies the output columns to be displayed in the Routing Results Browser
Select	Lets you select either all or none parameters for which output should be displayed. The parameters are: Rule Violations, Symmetry Violations, Matched Length Violations, Shield Violations, Opens, Shorts, DRCs, Wirelength, Vias, Ratio, Pin count, Manhattan X, and Manhattan Y.

Routing Assistant Command Buttons

The following table lists the functions of the different command buttons in the Routing assistant:

Icon	Command	Description
	Snap pins to WSPs	Snaps IO pins to width spacing patterns.
	Show WSP Manager	Displays WSP Manager.
	Import WSPs	Imports width spacing patterns to the current cellview.
	Auto-generate WSPs	Generates width spacing patterns automatically on the selected layers.
	Run pre-route checks	Runs pre-routing checks and saves the result to a log file.
	Run Power route	Runs power routing.
	Run Signal router/Finish Routing	Runs signal routing.
	Generate mesh routing	Runs mesh routing to let you create mesh on the specified layers.
	Generate P2T routing	Runs signal routing.
	Show results browser	Displays the Virtuoso Routing Results Browser.

Virtuoso Automated Device Placement and Routing Flow Guide
Product Version IC23.1, November 2023