math_real problem with sin function

[germandj]

Hi, I'm an Eng. Electronic trying to modulate a communication channel on VHDL. That's why I need to use the library math_real, but I'm having problems to use it.
I declared to signals a,b as real to try to use the sin function as example. The simple code

signal e,d: real;

c <= sin(d);

Gives me next error: VHDL error at <location>: real type object <e> cannot be used in operations.

What do I need to do in order to use the function correctly?

PS: I'm using Quartus II from altera and I couldn't load the library normally. I had to use it as work library...

 

[jezwold]

Real types are not supported by any synthesis tools available today.Which is why you got that error message.

 

[senjed]

for any trigonometric function in synthesis you could use CORDIC algorithm. I myself have not used it but i know it does the job well. for more info search internet and you'll find a lot; or contact me and I can send you some articles

 

[germandj]

Hi,
I was checking a little bit the CORDIC algorithm, but on the math_real library it seems to be using it.
Do you have an article where it explains how to use CORDIC on VHDL? Is there any library or something like it.
Thank you