Atmel CAVR-4 Manual De Usuario

CAVR-4

Part1. Using the compiler

This chapter describes the runtime environment in which an application 

executes. In particular, it covers the CLIB runtime library and how you can 

optimize it for your application.

The standard library uses a small set of low-level input and output routines for 

character-based I/O. This chapter describes how the low-level routines can be 

replaced by your own version. The chapter also describes how you can choose 

printf and scanf formatters.

The chapter then describes system initialization and termination. It presents 

how an application can control what happens before the start function main is 

called, and the method for how you can customize the initialization. Finally, the 

C-SPY runtime interface is covered.

Note that the legacy CLIB runtime environment is provided for backward 

compatibility and should not be used for new application projects.

For information about migrating from CLIB to DLIB, see the 

The CLIB runtime environment includes the C standard library. The linker will include 
only those routines that are required—directly or indirectly—by your application. For 
detailed reference information about the runtime libraries, see the chapter Library 
functions.

IAR Embedded Workbench comes with a set of prebuilt runtime libraries, which are 
configured for different combinations of the following features:

●

Type of library

●

Processor option (

-v

)

●

Memory model option (

--memory_model

)

●

AVR enhanced core option (

--enhanced_core

)