Cadence Environment
Help Resources
Cadence Help for the .cdsenv file:
- Run "cdnshelp" at the UNIX terminal to load the Cadence Help.
- DFII, Virtuoso Design Environment User Guide, Chapter 7 - Specifying Environment Settings
Set environment variable CDS_LOAD_ENV to addCWD to load ~/.cdsenv, and then load currentWorkingDirectory/.cdsenv.
export CDS_LOAD_ENV=addCWD
Environment Variables
Pins in a layout indicate the physical location of terminals that correspond to pins in the schematic. Pins are added to a layout to indicate their physical location which corresponds to logical pins in the schematic. These pins are identified by name. By default, the pin names in the layout editor are not shown. To display the pin names, either interactively check the box labeled Pin Names under Options → Display, or add the following to the .cdsenv file to always display pin names:
layout displayPinNames boolean t
The snapMode variable determines how the Create command entry points snap to the grid in the Layout editor. In the GUI, this corresponds to Options → Display → Snap Modes - Create. The segSnapMode variable determines how Edit command entry points snap to the grid in the Layout editor. In the GUI, this corresponds to Options → Display → Snap Modes - Edit. To set default snap modes, put the following in the .cdsenv file:
layout snapMode string "anyAngle" ; Snap Mode - Create layout segSnapMode string "anyAngle" ; Snap Mode - Edit
The X and Y grid spacing in the Layout editor are controlled by the xSnapSpacing and ySnapSpacing environment variables. These can be set in the .cdsenv file as shown below. Note, the NCSU CDK automatically overwrites these values in the "<ncsu>/skill/menus/triggers.il" script. The "<ncsu>/cdssetup/cdsenv" file says that the snap spacing is set to be a multiple of all the mfgGridResolutions and that the correct value is set in the trigger script.
layout xSnapSpacing float 0.05 ; X grid spacing measured in microns layout ySnapSpacing float 0.05 ; Y grid spacing measured in microns
Other useful environment variable options:
schematic srcSolderOnCrossover cyclic "ignored" ui undoLevel int 128 ui infix boolean t ui showScrollBars boolean t layout stopLevel int 32 spectre.envOpts modelFiles string "/usr/local/cadence/ncsu/models/spectre/nom/ami06N.m /usr/local/cadence/ncsu/models/spectre/nom/ami06P.m"
