Fixed-Point Blockset

Customizing Generated Code

You can customize generated code by directly modifying the Target Language Compiler file fixpttarget.tlc, which is located in the fixpoint directory. The two most important customizations are described below.

Macros Versus Functions

You can modify the TLC file to generate macros or C functions calls. With macros, you can avoid the overhead of a function call. With function calls, you can significantly reduce the overall code size for large routines. Additionally, many debuggers will not allow you to single-step through macros. This is not the case with function calls. The factory default setting is to generate macros.

Bit Sizes for Target C Compiler

You can modify the TLC file to accommodate custom target sizes by explicitly specifying the number of bits defined for char, short, int, or long data types.

If you do not manually override these sizes, then the sizes for the MATLAB host computer are automatically selected. For example, if you are running MATLAB under the Windows operating system, then char, short, int, and long default to 8, 16, 32, and 32 bits, respectively. Most other supported operating systems use the same data type sizes. However DEC Alpha, for example, defines a long as 64 bits.

Rapid Simulation Target

Selected Bibliography