Virtuoso XL Layout Editor User Guide

Using the Virtuoso Custom Placer

Figure 9-7 Standard Cells with Power Rails Parallel to the Row Direction

Row Shape

About Space at the End of a Row, and Row Compaction

The placer can abut MOS devices so that rails meet each other. However, when placing standard or other cells that are not set up for device abutment, the placer does not compact the rows to ensure that the rails abut.

The placer never extends rails to the row boundary. If the cells do not entirely fill the row, you may need to extend the rails or use filler cells.

Figure 9-8 on page 308 shows standard cells placed within a row. The cells do not abut each other and the power rails do not extend to the right side row boundary.

Figure 9-8 Row with Extra Space

Choose Component Types Form

From the Placement Planning form, in Manual User-Defined mode, the Edit button in the Types section opens the Choose Component Types form. Use this form to identify the component types to place in the currently active rows.