Atmel CAVR-4 ユーザーズマニュアル
CAVR-4
Part 1. Using the compiler
Getting started
13
The command line option -
e
makes the extended keywords available, and reserves them
so that they cannot be used as variable names. See, -e, page 179 for additional
information.
information.
For detailed descriptions of the extended keywords, see the chapter Extended keywords.
To read about special function types, see Special function types, page 29.
To read about special function types, see Special function types, page 29.
PRAGMA DIRECTIVES
The pragma directives control the behavior of the compiler, for example how it allocates
memory, whether it allows extended keywords, and whether it issues warning messages.
memory, whether it allows extended keywords, and whether it issues warning messages.
The pragma directives are always enabled in the AVR IAR C/C++ Compiler. They are
consistent with ISO/ANSI C, and are very useful when you want to make sure that the
source code is portable.
consistent with ISO/ANSI C, and are very useful when you want to make sure that the
source code is portable.
For detailed descriptions of the pragma directives, see the chapter Pragma directives.
PREDEFINED SYMBOLS
With the predefined preprocessor symbols, you can inspect your compile-time
environment, for example time of compilation, the processor variant, and memory
model in use.
environment, for example time of compilation, the processor variant, and memory
model in use.
For detailed descriptions of the predefined symbols, see the chapter The preprocessor.
HEADER FILES FOR I/O
Standard peripheral units are defined in device-specific I/O header files with the
filename extension
filename extension
h
. The product package supplies I/O files for all devices that are
available at the time of the product release. You can find these files in the
avr\inc
directory. Make sure to include the appropriate include file in your application source
files. If you need additional I/O header files, they can easily be created using one of the
provided ones as a template.
files. If you need additional I/O header files, they can easily be created using one of the
provided ones as a template.
For an example, see Accessing special function registers, page 133.
ACCESSING LOW-LEVEL FEATURES
For hardware-related parts of your application, accessing low-level features is essential.
The AVR IAR C/C++ Compiler supports several ways of doing this: intrinsic functions,
mixing C and assembler modules, and inline assembler. For information about the
different methods, see Mixing C and assembler, page 93.
The AVR IAR C/C++ Compiler supports several ways of doing this: intrinsic functions,
mixing C and assembler modules, and inline assembler. For information about the
different methods, see Mixing C and assembler, page 93.