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<h4 class="subsection">3.17.3 AVR Options</h4>

<p><a name="index-AVR-Options-1036"></a>
These options are defined for AVR implementations:

     <dl>
<dt><code>-mmcu=</code><var>mcu</var><dd><a name="index-mmcu-1037"></a>Specify ATMEL AVR instruction set or MCU type.

     <p>Instruction set avr1 is for the minimal AVR core, not supported by the C
compiler, only for assembler programs (MCU types: at90s1200, attiny10,
attiny11, attiny12, attiny15, attiny28).

     <p>Instruction set avr2 (default) is for the classic AVR core with up to
8K program memory space (MCU types: at90s2313, at90s2323, attiny22,
at90s2333, at90s2343, at90s4414, at90s4433, at90s4434, at90s8515,
at90c8534, at90s8535).

     <p>Instruction set avr3 is for the classic AVR core with up to 128K program
memory space (MCU types: atmega103, atmega603, at43usb320, at76c711).

     <p>Instruction set avr4 is for the enhanced AVR core with up to 8K program
memory space (MCU types: atmega8, atmega83, atmega85).

     <p>Instruction set avr5 is for the enhanced AVR core with up to 128K program
memory space (MCU types: atmega16, atmega161, atmega163, atmega32, atmega323,
atmega64, atmega128, at43usb355, at94k).

     <br><dt><code>-mno-interrupts</code><dd><a name="index-mno_002dinterrupts-1038"></a>Generated code is not compatible with hardware interrupts. 
Code size will be smaller.

     <br><dt><code>-mcall-prologues</code><dd><a name="index-mcall_002dprologues-1039"></a>Functions prologues/epilogues expanded as call to appropriate
subroutines.  Code size will be smaller.

     <br><dt><code>-mtiny-stack</code><dd><a name="index-mtiny_002dstack-1040"></a>Change only the low 8 bits of the stack pointer.

     <br><dt><code>-mint8</code><dd><a name="index-mint8-1041"></a>Assume int to be 8 bit integer.  This affects the sizes of all types: A
char will be 1 byte, an int will be 1 byte, a long will be 2 bytes
and long long will be 4 bytes.  Please note that this option does not
comply to the C standards, but it will provide you with smaller code
size. 
</dl>

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