I've been working with an AT32UC3C1512C microcontroller using the ADC to 
read four values from a PSD. I then want to apply an equation to the 
four digital outputs to obtain a position, but it involves dividing some 
of these outputs. Here I have run into a bit of a wall. Just using plain 
division (/) won't work because it doesn't give me the correct value 
when I pass it through the DAC and read it out. Therefore I tried to 
look at some digital division algorithms, but that would involve the use 
of assembly, and I'm not sure how to integrate this with a 32 bit 
microcontroller. I found an application note from Atmel on how to 
combine assembler and C, but I can't find the example code which the 
whole note is based on, and so it doesn't help at all. Does anyone know 
how to get around this?

Maybe it is easier to multiply by 1/X than to divide by X...

Otherwise if the division doesn't work, your setup may be broken...

Are you using float or int numbers?