Re: A Question on IQ Math Library

vickykulkarni wrote:
Hi

I need to use the IQ math library of TIC2000 on eZdsp f2812. I have some
questions about it:

1. It is my understanding that I can use the IQ math library to get a bit
equivalent of floating point number. For example if i want to write into a
16 bit register values from 0 to 1 (like .2,.3,.5 etc) like a sine wave
between -1 & 1 to generate an output. I can use this library to get a 16
bit equivalent of the number. Is this correct?
Basically what i want is to use a 16 bit register to output a waveform
like a sine wave etc or generate my own type of waveform
real=_IQ(0.4);

2.I have 2 analog input signals coming into the ADC. suppose I call them
real & imag. The ADC gives a 12 bit representation of each input sample.
If i right shift the value by 4 & save it in a 16 bit register. Can i use
the IQmag function to get a 16 bit magnitude equivalent of real & imag?
As: sdata =_IQmag(real,imag);//

This is ofcourse when global Q is set to 15.

Any help/tips/advice is highly appreciated. Thanks.

Here's a tip: you need guard bits. A magnitude computed from two 16-bit values may not fit into 16 bits.

Jerry
--
Engineering is the art of making what you want from things you can get.
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
.

Relevant Pages

  • A Question on IQ Math Library
    ... Basically what i want is to use a 16 bit register to output a waveform ... 2.I have 2 analog input signals coming into the ADC. ... The ADC gives a 12 bit representation of each input sample. ... the IQmag function to get a 16 bit magnitude equivalent of real & imag? ...
    (comp.dsp)
  • Re: anti-aliasing
    ... Suppose one were firing an adc at some fixed rate, ... I could add a pseudo-random delay after every adc sample shot; ... any waveform, to avoid getting just a slice. ... the harmonics of the sampling rate. ...
    (sci.electronics.design)
  • Re: DSO2250 AC-DC coupling
    ... The apparent change was due to the shift of the waveform on the ... Sounds more and more like they do the offset before the ADC and the ... display limits (this evidenced by manipulating math functions to ... pronounced on channel 2 (the channel used to demonstrate in the ...
    (sci.electronics.design)
  • Re: DSO2250 AC-DC coupling
    ... It was a positive pulse waveform that shifted down-screen ... Sounds more and more like they do the offset before the ADC and the ... display limits (this evidenced by manipulating math functions to ... pronounced on channel 2 (the channel used to demonstrate in the ...
    (sci.electronics.design)
  • Re: Synthesis Of WideBand Waveform
    ... I have a 400MHz bandwidth analog real waveform & I want to digitise ... it using ADC. ... What i have instead is a 4 channel ADC which can ... wideband waveform using 4 channels simultaneously sampling at 200MHz (each ...
    (comp.dsp)