Virtuoso XL Layout Editor User Guide
Setting Up Device Abutment for Virtuoso XL Layout Editor
6.If the cells can be abutted (the abutment connection condition is 1 or 2), the cells are abutted to the reference edges and the pins are aligned perpendicular to the direction of abutment.
If the cells cannot be abutted (the abutment connection condition is 3), they remain in their original configuration.
Sample Parameterized Cells Set Up for Abutment
Example 1
The generic example below shows what each of the different parts does.
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;Function: abutFunction(iA iB pA pB pASide connection event @optional (group nil))
;Inputs: group - the abutment group that these two cells belong to.
;_______________________________________________________________
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iA |
= Instance Id of cell that will move during abutment |
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iB |
= Instance Id of cell being abutted to |
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pA |
= Overlapping Pin Fig of iA |
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pB |
= Overlapping Pin Fig of iB |
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pASide |
= Abutting pin access direction |
;_______________________________________________________________
;connection = an integer value of 1 or 2 that indicates:
;
;1. pins are connected to the same net and do not
;connect to any other pin.
;
;2. pins are connected to the same net and the net
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;connects to other pins
;_______________________________________________________________
; |
event |
= integer that represents abutment event: |
;
;1. compute abutment offset
;2. pcell parameter adjustment for abutment
;3. pcell parameter adjustment for unabutment
;_______________________________________________________________
; |
group |
= abutment group pointer available to events 2 and 3 |
;_______________________________________________________________
;Outputs: depends
;
; Side effects:
;
procedure( abutFunction(iA iB pA pB pASide connection event @optional (group nil))
prog((result)
case(event
(1 ; Compute offset
result = getAbutmentOffset(iA iB pA pB pASide connection)
)
(2 ; Adjust pcell parameters
result = setAbutmentParams(iA iB pA pB pASide connection group)
)
(3 ; Adjust pcell parameters back to default resetAbutmentParams(group iA iB) result = t
)
(t ; Anything else return a nil result = nil
)
)
return(result)
)
)
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Example 2
This example shows how to add abutment properties to pins in an inverter pcell.
.; *** the following 4 pins |
are on metal1 and are on *** |
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|||
; |
*** |
the power and ground rails. This |
will allow |
*** |
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; |
*** |
abutment to other |
standard cells |
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*** |
obj = leftVddPin~>dbId
dbReplaceProp(obj "abutAccessDir" "list" list("left")) dbReplaceProp(obj "abutClass" "string" "stdcell") dbReplaceProp(obj "abutFunction" "string" "stdCellFunc")
;*** the following property is a technique for passing ***
;*** information to the user defined function. In this ***
;*** case the minimum cell height is dependent on many ***
;*** factors including design rules and is originally ***
;*** calculated in the pcell code. This avoids ***
;*** duplicating calculations in the user-defined ***
;*** function ****
dbReplaceProp(obj "minCellHeight" "float" minH)
obj = rightVddPin~>dbId
dbReplaceProp(obj "abutAccessDir" "list" list("right")) dbReplaceProp(obj "abutClass" "string" "stdcell") dbReplaceProp(obj "abutFunction" "string" "stdCellFunc") dbReplaceProp(obj "minCellHeight" "float" minH)
obj = leftGndPin~>dbId
dbReplaceProp(obj "abutAccessDir" "list" list("left")) dbReplaceProp(obj "abutClass" "string" "stdcell") dbReplaceProp(obj "abutFunction" "string" "stdCellFunc") dbReplaceProp(obj "minCellHeight" "float" minH)
obj = rightGndPin~>dbId
dbReplaceProp(obj "abutAccessDir" "list" list("right")) dbReplaceProp(obj "abutClass" "string" "stdcell") dbReplaceProp(obj "abutFunction" "string" "stdCellFunc") dbReplaceProp(obj "minCellHeight" "float" minH)
;*** The following 4 pins are the diffusion pins ***
;*** of the individual MOS devices in the inverter ***
;*** this will allow abutment of other individual ***
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; *** MOS devices to the inverter ***
obj = POutPin~>dbId
dbReplaceProp(obj "abutAccessDir" "list" list("right")) dbReplaceProp(obj "abutClass" "string" "ptran") dbReplaceProp(obj "abutFunction" "string" "mosAbutFunc") dbReplaceProp(obj "contactParam" "string" "POutCnts") dbReplaceProp(obj "w" "float" pw)
; *** these spacing properties are used if abutment fails dbReplaceProp(obj "vxlInstSpacingDir" "list" list("right")) dbReplaceProp(obj "vxlInstSpacingRule" "float" .35 )
obj = NOutPin~>dbId
dbReplaceProp(obj "abutAccessDir" "list" list("right")) dbReplaceProp(obj "abutClass" "string" "ntran") dbReplaceProp(obj "abutFunction" "string" "mosAbutFunc") dbReplaceProp(obj "contactParam" "string" "NOutCnts") dbReplaceProp(obj "w" "float" nw)
dbReplaceProp(obj "vxlInstSpacingDir" "list" list("right")) dbReplaceProp(obj "vxlInstSpacingRule" "float" .35 )
obj = PPwrPin~>dbId
dbReplaceProp(obj "abutAccessDir" "list" list("left")) dbReplaceProp(obj "abutClass" "string" "ptran") dbReplaceProp(obj "abutFunction" "string" "mosAbutFunc") dbReplaceProp(obj "contactParam" "string" "PPwrCnts") dbReplaceProp(obj "w" "float" pw)
dbReplaceProp(obj "vxlInstSpacingDir" "list" list("left")) dbReplaceProp(obj "vxlInstSpacingRule" "float" .35 )
obj = NPwrPin~>dbId
dbReplaceProp(obj "abutAccessDir" "list" list("left")) dbReplaceProp(obj "abutClass" "string" "ntran") dbReplaceProp(obj "abutFunction" "string" "mosAbutFunc") dbReplaceProp(obj "contactParam" "string" "NPwrCnts") dbReplaceProp(obj "w" "float" nw)
dbReplaceProp(obj "vxlInstSpacingDir" "list" list("left")) dbReplaceProp(obj "vxlInstSpacingRule" "float" .35 )
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