Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

Polynomial Evaluation

Hello, I'm totally new to VHDL and i'm trying to do a polynonamial evaluation. In particular I have a signed 16 bit value (x) and I want to obtain y=d*x^3+c*x^2+b*x+a. I have created a sig...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
12 years ago

Thank you Kaz,

you remove 16 lsbs from each mult result. thus

x*x means 16bits*16bits => 32 bits,

Got it !

discard 16 lsbs yielding 16 bits result as x^2 (but keep in head that it is x^2/2^16)

now x^2*x is 16bits * 16bits yielding 32 bits, discard 16 lsbs and so on.

So x^3 would be ((x^2/2^16)*x)/2^16, so when I sum, I have to add 32 zeros to x^3 ?

Am I right or I am missing something?

I can make it work !! i know !!