Texas Instruments MSP50C614 Function Prototypes and Declarations, Initializations, RAM Usage

C± ± Compiler

5.9.6Function Prototypes and Declarations

As mentioned above,

C± ± function prototypes and declarations MUST be preceded with the

keyword cmm_func.

Also, since all functions return through accumulator A0, all functions are of type integer, so that the function type can be omitted in the function declaration. If present, it is ignored anyway. Trying to typecast a function as returning a pointer will result in a compiler error.

Note: To change a C± ± program back into a regular C program (at least from the point of view of function prototypes and declarations), the following line can be inserted at the beginning of the C± ±program:

#define cmm_func

A library of regular C functions to substitute for the special MSP50P614/ MSP50C614 functions is supplied with the C± ± compiler, allowing the user to compare the results of regular C programs with those of C± ±programs. The library is contained in the C source file cmm_func.c .It should be linked with the C equivalent of the C± ± program, and run in Borland C.

5.9.7Initializations

Due (in part) to the architecture of the MSP50P614/MSP50C614 processor, initialization is only allowed for global variables. As a side effect, local static variables are not allowed. For example, a global array can be declared and initialized as follows:

int int_array[5]={1,2,3,4,5};

Initialization values are store in program memory.

5.9.8RAM Usage

RAM location 0 is reserved (and used intensively) by the compiler. The choice of location 0 does not conflict with the usual definition of a NULL pointer.

5.9.9Variable Types

As mentioned above, there are strong restrictions to the variable types that are recognized by C± ±.

5.9.10 String Functions

Arithmetic string functions are special functions that perform string arithmetic, of all things. The functions currently implemented are shown in Table 5±1.

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