Xic contains a facility for extracting a netlist from the physical database, and comparing it with the schematic in the electrical database. Xic can recognize devices in the physical layout, extract geometric and electrical data from these devices, and correspondingly update properties of electrical device instances. The netlists extracted from the physical and electrical databases can be compared. This layout vs. schematic (LVS) testing is a useful means of minimizing mask errors.
The Extract Menu contains command buttons for performing extraction and related functions. The commands are summarized in the table below, which provides the internal command name and a brief description.
|Setup||excfg||Extraction Setup||Set up and control extraction|
|Net Selections||exsel||Path Selection Control||Select groups, nodes, paths|
|Device Selections||dvsel||Show/Select Devices||Select and highlight devices|
|Source SPICE||sourc||Source SPICE File||Update from SPICE file|
|Source Physical||exset||Source Physical||Update electrical from physical|
|Dump Phys Netlist||pnet||Dump Phys Netlist||Save physical netlist|
|Dump Elec Netlist||enet||Dump Elec Netlist||Save electrical netlist|
|Dump LVS||lvs||Dump LVS||Save physical/electrical comparison|
|Extract C||exc||Cap Extraction||Extract capacitance using Fast[er]Cap|
|Extract LR||exlr||LR Extraction||Extract L/R using FastHenry|
In addition to the commands available from the Extract Menu, the extraction system provides a number of prompt-line commands which provide additional or supplemental capability. These include the !antenna command for testing the antenna effect on wire nets connected to MOS gates, and the !netext command for batch extraction of physical wire nets from a layout.