COS & SIN functions in VHDL

[avib]

Hi,

Does anybody know how to implement cos/sin functions in VHDL.
Or even better, is there any on the shelf IEEE cos/sin functions?

Thanks

 

[VHDLguy]

There is an ieee math_real package that seems to have COS/SIN functions. I have never used it, but Im sure it works ok. Not sure if its synthesizable or behavioural only.

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http://www.lateralsands.com/

 

[senjed]

for synthesizing trigonometric functions, there are two ways. the first is large-enough lookup tables (if it doesn't get too big). The second is algorithms named CORDIC. I have read about it, but don't know it exactly. However I know it works, and is reasonable. It could be pipelined or iterated.

 

[avib]

Thanks for your replies!

The reason I need these functions is that I need to implement conversion from Polar form to Rectangular form in FPGA (for Image processing)

I downloaded a CORDIC core from the opencores wesite but the Polar form to Rectangular is not implemented there yet (only Rectangular to Polar).

Please help!!!