The Device Selections Button: Show/Select Devices

The Device Selections button in the Extract Menu brings up the Show/Select Devices panel, from which devices can be made visible, and certain operations can be performed. There are three basic control groups.

The top control group contains a window which lists all of the devices extracted from the physical layout of the current cell. The listing has three columns. The Name and Prefix columns provide the values supplied in the technology file device block for the device. The third column gives the range of index values assigned for the device instances extracted. Each instance of a device has a unique index in this range.

The list is actually shown in response to pressing the Update List button. This will perform extraction/association on the current cell, if necessary, and list the devices found. With entries listed, the buttons above the listing become active. These buttons allow devices to be highlighted in the display windows.

Devices are highlighted is all windows showing the physical layout of the current cell. In addition, the corresponding electrical devices are also highlighted in windows showing the electrical schematic of the current cell.

Lines in the listing can be selected by clicking on the text. The buttons and other controls above the listing have the following functions.

Show All
All devices will be highlighted in the drawing windows.

Erase All
Erase all device highlighting in the drawing windows.

Show
The devices corresponding to the current selection in the list will be highlighted in the drawing windows. These are the devices that match the Name and Prefix selected, and whose indices are matched in the Indices entry text.

Erase The devices corresponding to the current selection in the list will be un-highlighted in the drawing windows. These are the devices that match the Name and Prefix selected, and whose indices are matched in the Indices entry text.

Indices
This is a text entry area where the user can provide a list of index integers and ranges to specify the index values of devices to highlight or un-highlight with the Show and Erase buttons. If the entry contains no text, all indices are used. The text consists of space or comma separated integers, or ranges of integers where the minimum and maximum values are separated by a hyphen (minus sign). For example: ``1,2-5,7,9-12''.

The second basic control group appears below the devices list, and enables devices to be selected by clicking on the device structure in the drawing windows. The command mode in initiated by pressing the Enable Select button. When in this mode, clicking on a device in a physical window showing the current cell will apply blinking highlighting to the device. The corresponding electrical device (if any) will also be shown with blinking highlighting in windows showing the electrical schematic of the current cell. In such windows, electrical device symbols can be clicked on, which will select the corresponding physical device.

Only one device can be selected at a time.

When the mode is active, the two check boxes to the right of the Enable Select button become active. When checked, information about new selections will be presented.

Show computed parameters of the selected device
When this box is checked, when a device is selected, the parameters extracted for the device will be printed on the prompt line. The format of the output is defined in the device block following the Cmput keyword.

Show elec/phys comparison of selected device
When this check box is active, clicking on a device will show a comparison of the extracted parameters and the corresponding electrical values for the device obtained from the schematic.

If one clicks on a device with the Shift key held, the electrical device properties will be set from the parameters extracted from the corresponding physical device. In an electrical window showing the device symbol, the device property labels will appear or change when the properties are set or updated.

The physical device must be specified in a device block, and have at least one parameter with the LVS keyword specified.

The third basic control group allows electrical parameters for the current layer to be measured for a rectangular region. If also allows rectangular regions to be painted, and can be used as an alternative to the box command in the side menu. Unlike the other two basic control groups, this group is only active in physical mode.

Electrical information is applied to layers in the with the Rsh keyword for resistance (or alternatively Rho or Sigma along with Thickness), the Capacitance keyword for capacitance, and the Tline keyword for transmission line parameters. The electrical specifications may be added or edited with the Edit Tech Params command in the Attributes Menu.

When the Enable Measure Box button is pressed, the command mode becomes active. The user can drag or click twice in physical windows to define a rectangular area. This area will be outlined with a highlighting box. During the creation, and after the box is created, the electrical parameters, if any, from the current layer are applied to the box dimensions, and the electrical parameters are displayed.

Once the box is created, pressing the Paint Box button, or pressing the p key, will paint the highlighting box with the current layer, creating a box object in the cell.

This is useful for creating simple rectangular resistors, for example, as the readout facilitates creating the proper size for the desired resistance. The command can also be used to measure the values of existing rectangular resistors.

The mouse operations can be repeated, as long as the command remains active. Only one highlighting rectangle is available at a time.