1<html lang="en"> 2<head> 3<title>AVR Options - Using the GNU Compiler Collection (GCC)</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="Using the GNU Compiler Collection (GCC)"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="up" href="Submodel-Options.html#Submodel-Options" title="Submodel Options"> 9<link rel="prev" href="ARM-Options.html#ARM-Options" title="ARM Options"> 10<link rel="next" href="Blackfin-Options.html#Blackfin-Options" title="Blackfin Options"> 11<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 12<!-- 13Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 141998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 152010 Free Software Foundation, Inc. 16 17Permission is granted to copy, distribute and/or modify this document 18under the terms of the GNU Free Documentation License, Version 1.3 or 19any later version published by the Free Software Foundation; with the 20Invariant Sections being ``Funding Free Software'', the Front-Cover 21Texts being (a) (see below), and with the Back-Cover Texts being (b) 22(see below). A copy of the license is included in the section entitled 23``GNU Free Documentation License''. 24 25(a) The FSF's Front-Cover Text is: 26 27 A GNU Manual 28 29(b) The FSF's Back-Cover Text is: 30 31 You have freedom to copy and modify this GNU Manual, like GNU 32 software. Copies published by the Free Software Foundation raise 33 funds for GNU development.--> 34<meta http-equiv="Content-Style-Type" content="text/css"> 35<style type="text/css"><!-- 36 pre.display { font-family:inherit } 37 pre.format { font-family:inherit } 38 pre.smalldisplay { font-family:inherit; font-size:smaller } 39 pre.smallformat { font-family:inherit; font-size:smaller } 40 pre.smallexample { font-size:smaller } 41 pre.smalllisp { font-size:smaller } 42 span.sc { font-variant:small-caps } 43 span.roman { font-family:serif; font-weight:normal; } 44 span.sansserif { font-family:sans-serif; font-weight:normal; } 45--></style> 46<link rel="stylesheet" type="text/css" href="../cs.css"> 47</head> 48<body> 49<div class="node"> 50<a name="AVR-Options"></a> 51<p> 52Next: <a rel="next" accesskey="n" href="Blackfin-Options.html#Blackfin-Options">Blackfin Options</a>, 53Previous: <a rel="previous" accesskey="p" href="ARM-Options.html#ARM-Options">ARM Options</a>, 54Up: <a rel="up" accesskey="u" href="Submodel-Options.html#Submodel-Options">Submodel Options</a> 55<hr> 56</div> 57 58<h4 class="subsection">3.17.3 AVR Options</h4> 59 60<p><a name="index-AVR-Options-1067"></a> 61These options are defined for AVR implementations: 62 63 <dl> 64<dt><code>-mmcu=</code><var>mcu</var><dd><a name="index-mmcu-1068"></a>Specify ATMEL AVR instruction set or MCU type. 65 66 <p>Instruction set avr1 is for the minimal AVR core, not supported by the C 67compiler, only for assembler programs (MCU types: at90s1200, attiny10, 68attiny11, attiny12, attiny15, attiny28). 69 70 <p>Instruction set avr2 (default) is for the classic AVR core with up to 718K program memory space (MCU types: at90s2313, at90s2323, attiny22, 72at90s2333, at90s2343, at90s4414, at90s4433, at90s4434, at90s8515, 73at90c8534, at90s8535). 74 75 <p>Instruction set avr3 is for the classic AVR core with up to 128K program 76memory space (MCU types: atmega103, atmega603, at43usb320, at76c711). 77 78 <p>Instruction set avr4 is for the enhanced AVR core with up to 8K program 79memory space (MCU types: atmega8, atmega83, atmega85). 80 81 <p>Instruction set avr5 is for the enhanced AVR core with up to 128K program 82memory space (MCU types: atmega16, atmega161, atmega163, atmega32, atmega323, 83atmega64, atmega128, at43usb355, at94k). 84 85 <br><dt><code>-mno-interrupts</code><dd><a name="index-mno_002dinterrupts-1069"></a>Generated code is not compatible with hardware interrupts. 86Code size will be smaller. 87 88 <br><dt><code>-mcall-prologues</code><dd><a name="index-mcall_002dprologues-1070"></a>Functions prologues/epilogues expanded as call to appropriate 89subroutines. Code size will be smaller. 90 91 <br><dt><code>-mtiny-stack</code><dd><a name="index-mtiny_002dstack-1071"></a>Change only the low 8 bits of the stack pointer. 92 93 <br><dt><code>-mint8</code><dd><a name="index-mint8-1072"></a>Assume int to be 8 bit integer. This affects the sizes of all types: A 94char will be 1 byte, an int will be 1 byte, a long will be 2 bytes 95and long long will be 4 bytes. Please note that this option does not 96comply to the C standards, but it will provide you with smaller code 97size. 98</dl> 99 100 </body></html> 101 102