User`s guide

113Targeting MC56F83xx/DSP5685x Controllers

C for DSP56800E

This chapter explains considerations for using C with the DSP56800E processor. Note

that the DSP56800E processor does not support:

• The C++ language

• Standard C trigonometric and algebraic floating-point functions (such as sine,

cosine, tangent, and square root)

Furthermore, C pointers allow access only to X memory.

NOTE

The DSP56800E MSL implements a few trigonometric and algebraic

functions, but these are mere examples that the DSP56800E does not

support.

This chapter contains these sections:

• Number Formats

• Calling Conventions and Stack Frames

• User Stack Allocation

• Data Alignment Requirements

• Code and Data Storage

• Large Data Model Support

• Optimizing Code

• Deadstripping and Link Order

Number Formats

This section explains how the CodeWarrior compiler implements ordinal and floating-

point number types for 56800E processors. For more information, read limits.h

and float.h, under the M56800E Support folder.

Table 6.1

shows the sizes and ranges of ordinal data types.