dbCreateRailDef

dbCreateRailDef( 
d_cellViewId 
t_raildDefName
t_netName
l_lpp
t_rowReference
t_railReference
g_width
[ g_offset ]
[ g_beginOffset ]
[ g_endOffset ]
)
=> d_railDef / nil

Description

This function creates a container of attributes to define a row rail. The definition can be referenced in more than one row or placeArea. If a physical attribute is modifed in the object, it is instantly reflected in all row/placeArea that reference the railDef.

Arguments

d_cellViewId	Database ID of a cellview.
t_railDefName	Name of the railDef.
t_netName	Name of the net.
l_lpp	Layer and purpose of the rail geometry.
t_rowReference	Specifies row reference. Valid Values: `bottomAlignment`, `centerAlignment`, `topAlignment`.
t_railReference	Specifies rail reference. Valid Values: `bottomAlignment`, `centerAlignment`, `topAlignment`.
g_width	Width of rail geometry.
g_offset	Optional. If this value is specified, then the rail is placed at the specified distance (in user units) from the two reference points (rail and row). A negative value indicates offsetting the rail below the top/bottom edge of the row and a positive value indicates offsetting the rail above the top/bottom edge.
g_beginOffset	Optional. This value offsets or extends the rail by the specified user units from the left edge of the row. A negative value indicates offsetting the rail towards the left side of the left edge of the row and a positive value indicates offsetting the rail towards the right side of the left edge of the row.
g_endOffset	Optional. This value offsets or extends the rail by the specified user units from the right edge of the row. A negative value indicates offsetting the rail towards the left side of the right edge of the row and a positive value indicates offsetting the rail towards the right side of the right edge of the row.

Value Returned

d_railDef	Returns the database ID of the railDef.
`nil`	An error occurred during execution.

Examples

Creates railDef

def = dbCreateRailDef(cellViewId
     "myRailDef"
      "netName"
      list("layer" "purpose")
      "bottomAlignment"
      "bottomAlignment"
      railWidth
     offsetFromRowReference)

The following example shows two rails aligned to a row. The offset value for the first rail is 0. So, in the figure shown below the top of the first rail is aligned to the top edge of the row. The offset value for the second rail is also 0. Therefore, the bottom of the second rail is aligned to the bottom edge of the row.

Setting the offset value for the first rail to 0.4 and the value for the second rail to 0.3 will place the two rails in the row as shown in the figure below:

The following table specifies, in addition to the offset values, the begin and end offset values for the two rails.

Rail	Offset	Begin offset	End offset
Top rail	0.4	-0.8	+1.2
Bottom rail	0.3	+1.5	-1.8

A negative begin/end offset value sets the rail relative to the left side of the row and positive begin/end offset value stes the rail relative to the right side of the row. This is shown in the figure below:

Virtuoso Studio Design Environment SKILL Reference
Product Version IC23.1, November 2023