Atmel AVR Microcontroller Basic Math Code Library for Multiplication

• Multiply 8 bits by 8 bits in software unsigned by http://www.avr-asm-tutorial.net
• Multiply 8 bits by 8 bits in software unsigned by http://elm-chan.org
• Multiply 8 bits by 8 bits in software signed based on code by http://elm-chan.org
• Multiply 16 bits by 16 bits in software by http://elm-chan.org
• Multiply 32 bits by 32 bits in software by http://elm-chan.org

See also:

• http://www.avr-asm-tutorial.net/avr_en/calc/MULTIPLICATION.html Very nice tutorial on assembly language multiplication.