Software module descriptions – Motorola USB08 User Manual

Page 58

Advertising
background image

Designer Reference Manual

USB08 Evaluation Board

58

Software Module Descriptions

MOTOROLA

Software Module Descriptions

because this application does not use problematic constructions, like bit
fields in the source code.

In some places, using individual assembler instructions in the form of
in-line assembler directives is considered useful, for example, for the
interrupt enable in the main module

U08MAIN.C

. For this purpose, the

Cosmic C Compiler offers the following instruction:

_asm("<assembly statement >");

When using other compilers, similar instructions should be available.
However, some small syntactic adjustments can be necessary. Beside
the main module, the modules

U08232.C

and

U08ADC.C

also contain

such in-line assembler constructions.

The marking of a function as an interrupt service routine is not regulated
in the ANSI-C standard. For lack of a uniform regulation, the different
compilers handle this necessary marking in a different way. For
example, the Cosmic C Compiler uses the modification @interrupt:

@interrupt void interrupt_handler();

Other compilers use “#pragma” instructions to mark interrupt functions.

Advertising