Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.

- Community Forums
- :
- Forums
- :
- Hardware Development
- :
- AI Engine, DSP IP and Tools
- :
- fraction arithmetic

- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Mute
- Printer Friendly Page

Highlighted

shreyassg13@gmail.com

Participant

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

06-06-2011 01:33 AM

3,435 Views

Registered:
02-22-2011

Hello,

I am implementing CORDIC algorithm, in one paper they have used fixed point arithmetic, I wanted to know how to do +,-,*,/ operations in this representaion. is this the best or floating point is better?

1 Solution

Accepted Solutions

Highlighted

hwneff

Visitor

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

06-09-2011 04:02 PM

3,690 Views

Registered:
11-18-2008

to answer your last question about whether to do integer or floating point requires

a lot more information about what you need and how fast you need to compute

that which you need.

based, however, on your initial comment about fixed point, i would suggest you

should investigate something called "q notation" -- a convention that uses

integer-ish numbers and functions to operate on "fractions".

NB: the word "convention" -- it is just that: whether the binary digit sequence

"10000000" is 127 or 1 or 0.5 is all a matter of how one has chosen to look at it.

for starters, have a look at wikipedia:

http://en.wikipedia.org/wiki/Q_%28number_format%29

once you have the technique, then revisit those cordic papers and, if appropriate,

revisit your problem to determine the apporpriate values and ranges to be using

as you apply what you've learned.

2 Replies

Highlighted

bassman59

Historian

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

06-06-2011 09:56 AM

3,430 Views

Registered:
02-25-2008

@shreyassg13@gmail.com wrote:

Hello,

I am implementing CORDIC algorithm, in one paper they have used fixed point arithmetic, I wanted to know how to do +,-,*,/ operations in this representaion. is this the best or floating point is better?

It depends on your application's requirements.

----------------------------Yes, I do this for a living.

Highlighted

hwneff

Visitor

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Email to a Friend
- Report Inappropriate Content

06-09-2011 04:02 PM

3,691 Views

Registered:
11-18-2008

to answer your last question about whether to do integer or floating point requires

a lot more information about what you need and how fast you need to compute

that which you need.

based, however, on your initial comment about fixed point, i would suggest you

should investigate something called "q notation" -- a convention that uses

integer-ish numbers and functions to operate on "fractions".

NB: the word "convention" -- it is just that: whether the binary digit sequence

"10000000" is 127 or 1 or 0.5 is all a matter of how one has chosen to look at it.

for starters, have a look at wikipedia:

http://en.wikipedia.org/wiki/Q_%28number_format%29

once you have the technique, then revisit those cordic papers and, if appropriate,

revisit your problem to determine the apporpriate values and ranges to be using

as you apply what you've learned.