[Open-graphics] Other interesting bits of math to do in FPGAs

[Timothy Normand Miller]

On 9/19/07, Hamish <hamish at travellingkiwi.com> wrote:
>
> Am I too old? Adding logs instead of multiplying (And subtracting instead of
> dividing) was how I learnt to do multiplication adn division before you werte
> allowed to use calculators in school exams (Early 1980's in NZ :)

http://en.wikipedia.org/wiki/Sliderule   :)

> Come to think of it, would it be more efficient (Thinking of time & logic vs
> table lookup space) to use a lookup table to caluclate log/alog like using
> Eton tables in the old days? Or actually calculating it?

For regular arithmetic, we want to compute it directly to maximize
accuracy.  I think.  But if you're doing lots of products, it may be
better to sum lots of logs instead, especially when you just want an
approximation.

-- 
Timothy Normand Miller
http://www.cse.ohio-state.edu/~millerti
Open Graphics Project