4.3.4 LISP Code

The customization of the generic XLISP interpreter for TCAD purposes is not only accomplished by adding C-coded primitives and by running external tools, but also by LISP-coded functions and modules. LISP code falls into one or more of the following categories.

• Tool-specific LISP interface code which is required to represent the tool on the task level as one or more virtual applications in form of LISP functions (see Figure 4.1).
• Interpreted parts of the user interface for batch-mode applications, centered around interactive ``tool control panels'' (see Figure 3.10).
• Modules which implement dedicated top-level functionality, like the integrating ``main'' shell or the simulation flow control module [86].
• Prototype code to evaluate new concepts.

Most of the LISP code is loaded at startup of the XLISP interpreter and additional code is loaded upon demand. Figure 4.5 shows the VISTA shell which can be considered as the ``main program''. All applications can be accessed from here via pull-down menus and pop-up panels, which are created by LISP code.

  
Figure 4.5: The VISTA main shell