Fat Wire Via Enclosure Rule The fat wire via enclosure rule specifies the

Fat wire via enclosure rule the fat wire via

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Fat Wire Via Enclosure Rule The fat wire via enclosure rule specifies the minimum amount of fat metal overlap over a via for the metal layer either above or below the via. The minimum overlap requirement depends on the width of the fat metal enclosing the via, the spacing of nearby metal, and the parallel length of the nearby metal, as specified in a table. This is the syntax of the rule: DesignRule { layer1 = "MetalX" layer2 = "ViaX" fatWireViaEncTblSize = 4 fatWireViaEncWidthThresholdTbl = (W1, W2, W3, W4) fatWireViaEncParallelLengthThresholdTbl = (L1, L2, L3, L4) fatWireViaEncMaxSpacingThresholdTbl = (S1, S2, S3, S4) fatWireViaEnclosureTbl = (E1, E2, E3, E4) fatWireViaArrayExcludedTbl = (0, 0, 0, 1) } Figure 2-62 shows how the minimum enclosure depends on the rule attributes.
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Chapter 2: Routing Design Rules Via Enclosure Rules 2-82 IC Compiler Technology File and Routing Rules Reference Manual D-2010.03-SP2 IC Compiler Technology File and Routing Rules Reference Manual Version D-2010.03-SP2 Figure 2-62 Fat Wire Via Enclosure Rule Here is an example of the rule: DesignRule { layer1 = "Mx" layer2 = "VIAx" fatWireViaEncTblSize = 4 fatWireViaEncWidthThresholdTbl = (0.055, 0.060, 0.075, 0.170) fatWireViaEncParallelLengthThresholdTbl = (0.12, 0.12, 0.14, 0.14) fatWireViaEncMaxSpacingThresholdTbl = (0.062, 0.068, 0.090, 0.134) fatWireViaEnclosureTbl = (0.008, 0.009, 0.012, 0.015) fatWireViaArrayExcludedTbl = (0, 0, 1, 0) } In this example, if the fat wire width W is greater than 0.055 but less than or equal to 0.060, the parallel length L of the nearby metal is greater than or equal to 0.12, and the spacing S to the nearby metal is less than 0.062, then the minimum enclosure E is 0.008. The last attribute, fatWireViaArrayExcludedTbl , is set to 1 to waive the rule for a double via for the corresponding set of values for W, L, S, and E. S n E n W n L n
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Chapter 2: Routing Design Rules Via Enclosure Rules 2-83 IC Compiler Technology File and Routing Rules Reference Manual Version D-2010.03-SP2 Concave Metal Corner Via Enclosure Rule The concave metal corner via enclosure rule specifies a minimum allowed distance between a concave metal corner and a via enclosed by the metal. In Figure 2-63 , the rule prohibits any concave metal corner within a rectangular exclusion area surrounding the via by a distance D. The rule does not apply to two vias enclosed by the same metal segments when the spacing between the vias is no more than S 0 , the minCutSpacing value specified in the ContactCode section of the technology file. Figure 2-63 Concave Metal Corner to Via Enclosure Rule Here is an example of the syntax used for this rule: DesignRule { layer1 = "M2" layer2 = "V1" concaveMetalToCutMinDist = 0.30 } In this example, any concave metal corner must be at least 0.30 distance units away from a single enclosed via. Note: This rule is supported only by Zroute. Violation DesignRule { layer1 = "M2" layer2 = "V1" concaveMetalToCutMinDist = D } D Violation No violation D Double via with spacing <= S 0 No violation D S 0
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Chapter 2: Routing Design Rules Jog Wire Rules 2-84 IC Compiler Technology File and Routing Rules Reference Manual D-2010.03-SP2 IC Compiler Technology File and Routing Rules Reference Manual Version D-2010.03-SP2 Jog Wire Rules
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