Chapter 2 Routing Design Rules Via Enclosure Rules 2 132 IC Compiler Technology

Chapter 2 routing design rules via enclosure rules 2

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Chapter 2: Routing Design Rules Via Enclosure Rules 2-132 IC Compiler™ Technology File and Routing Rules Reference Manual J-2014.09-SP2 IC Compiler™ Technology File and Routing Rules Reference Manual Version J-2014.09-SP2 Figure 2-110 Fat Wire Via Enclosure Rule With Corner Keepout Distance In Figure 2-111 , the corner keepout attribute is not used, and via C1 is half inside and half outside the parallel overlap region of the wide metal, so the fat wire via enclosure rule applies only to the lower portion of the via, highlighted in red in the figure. Via C2 is entirely outside the parallel overlap region of the wide metal, so the fat wire via enclosure rule does not apply at all to that via. Figure 2-111 Via Inside and Outside Fat Metal Parallel Length Region In Figure 2-112 , vias C1, C2, and C3 are all outside the parallel overlap region of the wide metal. By default, the fat wire via enclosure rule does not apply to these vias. S n E n W n L n K n Minimum enclosure value E applies when via corner keepout distance K is less than or equal to the table value fatWireViaCornerKeepoutDist Tbl= (K 1 , K 2 , K 3 , K 4 ) B1 A1 B2 A2 C1 C2 Wide metal Wide metal
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Chapter 2: Routing Design Rules Via Enclosure Rules 2-133 IC Compiler™ Technology File and Routing Rules Reference Manual Version J-2014.09-SP2 Figure 2-112 Exception to Via Outside Fat Metal Parallel Length Region However, you can optionally have the rule apply to the portion of via C3 that covers the parallel-length region between the wide metal and the nearby metal. This is the region marked by the dashed red rectangle in the diagram. To apply the rule to the portion of any via inside this region, use the following attribute setting: fatWireViaEncCheckViaOffFatWire = 1 When this attribute is set to 1, the fat wire via enclosure rule applies to vias that are off the fat wire but partially or completely inside the region between the fat metal and nearby metal. If this attribute is set to 0 or omitted from the design rule definition, the rule does not apply to any vias that are off the fat wire. Fat Metal Via Keepout Rules The fat metal via keepout rules are specified in the DesignRule section of the technology file by using the fatWireViaKeepoutTblSize , fatWireViaKeepoutWidthThreshold , fatWireViaKeepoutMinSize , fatWireViaKeepoutEnclosure , fatWireViaKeepoutParallelLengthThreshold , and fatWireViaKeepoutMaxSpacingThreshold attributes. Wide metal W n Narrow metal S n L n C1 C2 C3 Rule applies to shaded portion of C3 if fatWireViaEncCheckViaOffFatWire = 1
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Chapter 2: Routing Design Rules Via Enclosure Rules 2-134 IC Compiler™ Technology File and Routing Rules Reference Manual J-2014.09-SP2 IC Compiler™ Technology File and Routing Rules Reference Manual Version J-2014.09-SP2 You can use these attributes to define the following rules: The fat metal via keepout area rule The via enclosure rule The poly contact enclosure rule Note: The fat wire via keepout rules are still supported. However, for any new technology file, you should use the more advanced rules described in
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