Caltech Intermediate Form - Overview

Overview

Each statement in CIF consists of a keyword or letter followed by parameters and terminated with a semicolon. Spaces must separate the parameters but there are no restrictions on the number of statements per line or of the particular columns of any field. Comments can be inserted anywhere by enclosing them in parenthesis.

There are only a few CIF statements and they fall into one of two categories: geometry or control. The geometry statements are: LAYER to switch mask layers, BOX to draw a rectangle, WIRE to draw a path, ROUNDFLASH to draw a circle, POLYGON to draw an arbitrary figure, and CALL to draw a subroutine of other geometry statements. The control statements are DS to start the definition of a subroutine, DF to finish the definition of a subroutine, DD to delete the definition of subroutines, 0 through 9 to include additional user-specified information, and END to terminate a CIF file. All of these keywords are usually abbreviated to one or two letters that are unique.