minVoltageSpacing

Specifies the minimum spacing between two wire shapes on the same metal layer which have different voltages.

minVoltageSpacing Quick Reference

Constraint Type	Layer
Value Types	FltHeader1DTblValue
Database Types	Design, Technology
Scope	design, foundry
Category	Spacing

Value Type

minVoltageSpacing constraints have a FltHeader1DTblValue that consists of FltValue-Value pairs where FltValue represents the voltage and Value is the minimum spacing, in user units.

To determine the minimum spacing, the maximum voltage swing between shapes is calculated as (max(max voltage of each shape) - (min(min voltage of each shape))). This voltage is compared with the voltage values in the table to find the first value that is less than or equal to the calculated voltage swing. The corresponding minimum spacing is required.

minVoltageSpacing constraints can be applied to layer purpose pairs and nets. For more information on these applications, see Voltage-Dependent Rule Support.

Examples

For Metal1 shapes in this example,

• For voltage swings >= 0.0 and < 1.5, the minimum spacing is 0.06.
• For voltage swings >= 1.5 and < 3.3, the minimum spacing is 0.08.
• For voltage swings >= 3.3, the minimum spacing is 0.1.
  

  Format	Example
  Tcl	set_layer_constraint -constraint minVoltageSpacing \ -layer Metal1 -hardness hard -row_name voltage \ -FltHeader1DTblValue { 0.0 0.06 1.5 0.08 3.3 0.1 } \ -row_interpolation snap_down \ -row_extrapolation {snap_up snap_down}
  LEF	LAYER Metal1 PROPERTY LEF58_VOLTAGESPACING "VOLTAGESPACING 0.0 0.06 1.5 0.08 3.3 0.1 ;"
  Virtuoso	spacingTables( ( minVoltageSpacing "Metal1" ( "voltage" nil nil ) ( 0.0 0.06 1.5 0.08 3.3 0.1 ) ) );spacingTables

Related Topics

Spacing Constraints

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