cordic sincos output usage

Harsha G. OP (Company: panacea) #3696921
Rate this post
• ▲ useful
▼ not useful 
Hi all,



I m using cordic ip core in spartan 6 device,futher im getting the 
correct outputs too, but facing problem in multiplying tat output to 
some number( like pwm ontime).



For Example



Input: Pin(phase): 0001100100011110



Output: cos(theta):Xout: 0010110101000111



Output: Sin(theta):Yout: 0010110100111011





from above example,



Phase in = 45 degrees or 0.785 in radians in 2QN format.



Xout: 11591 in decimal format, 0.7071067 in 1QN format

Yout : 11579 in decimal format, 0.7071 in 1QN format



Now consider ,

I want to multiply 50 * Xout



     = 50 * 11591  is what im able to do,but actually i need to do this 
= 50 * 0.7071067





Please can any one help me out!!!!





Thanks in Advance
Reply Quote Edit Move Thread sperren Anmeldepflicht aktivieren Anpinnen Delete topic Thread mit anderem zusammenführen Report post
Martin Guest #3710344
Rate this post
• ▲ useful
▼ not useful 
Actually,
as long  as you do not have a floating point unit
instantiated, all you can do is integer arithmetics.

So, you do

 50 * 11591

and then right shift  the result to avoid overflow, keeping the number
of right shifts  in memory.
Reply Quote Edit Delete Report post
Watch this topic

Reply

Note: the original post is older than 6 months. Please don't ask any new questions in this thread, but start a new one.

Formatting
  • [c]C-Code[/c]
  • [vhdl]VHDL-Code[/vhdl]
  • [code]code in other languages, ASCII drawings[/code]
  • [math]formula (LaTeX syntax)[/math]
  • [[Title]] – link to an article
  • Link to another post: right-click its post ID (#8078628), copy the address, paste it into the text

More about formatting

Post long source code as an attachment, not in the text.

Your name and e-mail address

Already registered? Log in

Not shown to anyone. We send you a link; your post appears once you confirm it there.

By submitting you create a free account and accept the terms of use.