Chapter VII: DESIGN ENVIRONMENTS

icon

Lambda

icon


To allow scalable designs, the term lambda is used to refer to 1 grid unit of layout. The grid display and alignment all use this unit to describe sizes. In order to translate this to real units, lambda has a value which is measured in database units (usually half-millimicrons). The number of microns per lambda unit is shown in the status area under the heading "LAMBDA".
Figure 7.1
You can change the value of lambda with the Change Units... command of the Technology menu. A dialog is presented in which the current value is shown and a new value may be typed.

Besides changing the value of lambda, you can also change the internal units and the display units. Be careful if you change the internal database unit, because this may result in all data being scaled which may not be desirable.

When you change the display units, it only affects how numbers are presented, not their internal storage. For example, selecting the "Microns" display unit causes Electric to describe distances in microns, rather than lambda units. When a real display unit is used, appropriate notation is used to express distances (i.e. a 3 micron wire is "3u" wide).

By default, when you type a distance value in Electric, that value is presumed to be in lambda units. However, if you add a specific unit symbol to the end of the value, those units are used. These unit symbols are recognized:

Unit
Unit Symbol
Example
Inches
"
3"
Centimeters
cm
7cm
Millimeters
mm
12mm
Mils
mil
4.5mil
Microns
u
-90u
Centimicrons
cu
100cu
Millimicrons
mu
1mu


Prev Previous     Contents Table of Contents     Next Next