Using alt_multfp and other floating points operations from megawizard

Altera_Forum · ‎08-24-2011

Hello i have a code that is more or less like this:


  if (index< 48)
  begin
   // im <= im + (tensao * sen);
    //re <= re + (tensao * cos);
    index <= index+1;
  end
  
 end
mult    mult_im (
    .clock ( clkin_50 ),
    .dataa ( tensao ),
    .datab ( sen),
    .result ( im_w )
    );
mult    mult_re (
    .clock ( clkin_50 ),
    .dataa ( tensao),
    .result ( re_w )
    );

I want to do the multiplication using floating points of single precision. The mult float point megawizard function must do a new multiplication when my input value changes (at each new index). I also need to store the result (re_w and im_w).

Can someone help me? It looks like the mult function takes 10 cycles to complete and has a latency of 60.

Link to altera's PDF:

http://www.google.com.br/url?sa=t&source=web&cd=2&ved=0ccsqfjab&url=http%3a%2f%2fwww.altera.com%2fliterature%2fug%2fug_altfp_mfug.pdf&ei=ahtutr2diisnsqlz6yg8bw&usg=afqjcngy_hiepoyrnaqqkl-lzph9ztfyfq&sig2=9beyievwmrrqacyoq8ercw

Altera_Forum · ‎08-24-2011

how did you come up with a latency of 60? on page 23 the latency is specified as 5, 6, 10, or 11 clocks

Altera_Forum · ‎08-24-2011

Yup i think i was drunk (joking)

The latency is 10, so if i set my clock enable to 1 after 10 clocks i will have the result right?

What happens if i change my value in the 6th clock for example?