Hi Kuan,

At present tools cannot synthesize real numbers . Normally real

numbers are represented in fixed point format for synthesis.

Fixed point numbers are again represented as std_logic_vector with a

decimal point in between. User is reponsible to know where is the

decimal point and arithmetic operations done on it

There are fixed point packages availabe which does this work for you

but I have not used it yet ..

http://www.eda.org/vhdl-200x/vhdl-20...ges/files.html
Kuan I would suggest you to learn the basics of digital arithmetic

before you implement in hardware.