What kind of application requires fix or floating point DSP?

DSP Help

Hi

I need help 8O
It's the first time that I use a DSP for signal process elaborations and i I must choose between two dsp:
1. fix point
2. floating point

What kind of application required fix point or floating point ?
Have you any link ?

Thx

Re: DSP Help

Hi

You must tell us what kind of data you will processing!!!

For example, if who work with control aplications you have advantages in
using floating number representation. You can do the same work with fixed number representation with less number resolution, or emulate floting number representation in software.

Best Regards
Pendragon

Re: DSP Help

Hi pendragon

The use for which I have thought to use the DSP is for telephony applications.
I had thought to use DSP and codec of the Analog devices and decode the tones of the DTMF with use the FFT transform. From the specifics, the minimal interval between two tones is approximately of ms and I dont think to have problems with the time for the execution of FFT transform.
(Time for FFT = N/2*Log2(N) with N=256 and time for multiplication is 19 ns)
I's right ?

Thx
Defer

I think for a beginner it is better to begin with a floating point DSP , so that he/she can comfortably design the main algorithm and verify it's correctness.
In the second phase of the project, however, you can think about migrating the designed algorithm to a fixed point DSP, since it is much more chiper.
During the migration, you can try to optimize your design, and to reduce the total number of needed computations.
So, Do NOT begin with a fixed point DSP, as the first step. First, implement your design on a floating point one, and then, optimize it, for a fixed point DSP.
Have a look at TI's document, and the methodology of design in some of their app notes, you can see that they have some times used the same methodology, have a look at "Face recognition with C6000 DSP" aap note.

Re: DSP Help

Hi again

If you need to make FFT, depending the resolutiuon you need, I think that you will have great results using a fixed point number representation processor.
In my work I use the TMS320F240 from TI (16 bits ). When I whant more precision I represent the number with two or more words.

For more information see the link from TI:

http://dspvillage.ti.com/docs/catal...peFlagId=&ptemplateId=5121&pnavigationId=9104

Best Regards
Pendragon

Re: DSP Help

For beginner Analog Device's chips are simpler..
Try ADSP 218x family 16bit fixed point processors.

Re: DSP Help

Go through this book
DSP Fundamentals: Architectrure and Features.. Phil Lapsley


You will get a good idea

DSP Help

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