You can either use a higher precision or the following code fragment
to calculate the percentage of ul1 of ul2. The following code fragment
requires only 16 bit ints.

The For loop creates a variable p that is a binary fraction
of ul1/ul2  The format of p is essentially a fixed point number
of the form i.f where each i (integer) and f (fraction) are 8 bits.

Multiply p by 100 will give a percentage.
(add 0x80 to roundoff the percentage)
Shift the result by 8 bits will normalize the result to
an intereger value from a fixed point value.

Walter Banks

  {
    unsigned int16 x,ul1,ul2;
    ul1 = 4500;
    ul2 = 10000;

    unsigned int16 n,p,percent;
    x = ul1;
    p = 0;
    for (n = 8;n != 0; n--)
     {
      x <<= 1;
      p <<= 1;
      if (x > ul2)
       {
         x -= ul2;
         p++;
       }
     }
   percent = p * 100;
   percent >>= 8;
  }

Rich Mcelroy wrote:
>
> I'm using Bytecraft's compiler for MPLAB.  it does basic math, but the
> results I'm getting indicate that it is droping anything after the integer
> on my calculations.  I'm trying to calculate a percentage:
>
> Percent = A/B * 100;  something like that.

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