Atmel CAVR-4 Manual De Usuario

CAVR-4

Choosing formatters for printf and scanf

Reference Guide

For information about how to fine-tune the formatting capabilities even further, see 
Configuration symbols for printf and scanf, page 69.

 

To specify the 

printf

 formatter in IAR Embedded Workbench, choose 

Project>Options and select the General Options category. Select the appropriate 
option on the Library options page.

To use any other variant than the default (

_PrintfSmall

), add one of the following 

lines in the linker command file you are using:

-e_PrintfLarge=_Printf

-e_PrintfSmall=_Printf

-e_PrintfTiny=_Printf

In a similar way to the 

printf

 function, scanf uses a common formatter, called 

_Scanf

. The default version is very large, and provides facilities that are not required 

in many embedded applications. To reduce the memory consumption, two smaller, 
alternative versions are also provided in the standard C/C++ library.

The following table summarizes the capabilities of the different formatters:

Basic specifiers c, d, i, o, p, s, u, X, 

x

, and %

Yes

Yes

Yes

Multibyte support

*

*

*

Floating-point specifiers a, and A

Yes

No

No

Floating-point specifiers e, E, f, F, g, 

and G

Yes

No

No

Conversion specifier n

Yes

No

No

Scan set [ and ]

Yes

Yes

No

Assignment suppressing *

Yes

Yes

No

long long

 support

Yes

No

No