Re: problem in cos funtion

Altera_Forum · ‎07-15-2011

sir/mam,

i have used ieee math_real ,now

k1 : bwlmulti port map (a1,f,q1);

qout <= cos (q1);

here shows an error that "cos can't have such operand in this context". plz help me out of problem.:cry:

Altera_Forum · ‎07-15-2011

You cannot use the math_real package for synthesis.

In addition, you cannot use real types for synthesis.

They are only suitable for simulation.

Altera_Forum · ‎07-15-2011

If I need tackle cos operation, how can I do it

Altera_Forum · ‎07-15-2011

For a start, its best to use fixed point rather than floating point.

There are two main methods for cos function:

Use a lookup table.

Use the CORDIC algorithm. There are many implementations of this. Or have a look here:

http://en.wikipedia.org/wiki/cordic