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You will implement a fourth-order, elliptical, low-pass infinite impulse-response (IIR) filter as a cascade of two second-order sections.

Implementation

On the DSP, you will implement the elliptic low-pass filter designed using the ellip command from IIR Filters: Filter-Design Exercise in MATLAB . You should not try to implement the notch filter designed in IIR Filtering: Filter-Coefficient Quantization Exercise in MATLAB , because it will not work correctly when implemented using Direct Form II. (Whynot?)

To implement the fourth-order filter, start with a single set of second-order coefficients and implement a singlesecond-order section. Make sure you write and review pseudo-code before you begin programming. Once your single second-order IIR is working properly you canthen proceed to code the entire fourth-order filter.

Large coefficients

You may have noticed that some of the coefficients you have computed for the second-order sections are larger than 1.0in magnitude. For any stable second-order IIR section, the magnitude of the "0" and "2" coefficients( a 0 and a 2 , for example) will always be less than or equal to 1.0. However, the magnitude of the "1" coefficient can beas large as 2.0. To overcome this problem, you will have to divide the a 1 and b 1 coefficients by two prior to saving them for your DSP code. Then, in your implementation, you will have tocompensate somehow for using half the coefficient value.

Repeating code

Rather than write separate code for each second-order section, you are encouraged first to write one section, thenwrite code that cycles through the second-order section code twice using the repeat structure below. Because the IIRcode will have to run inside the block I/O loop and this loop uses the block repeat counter ( BRC ), you must use another looping structure to avoid corrupting the BRC .

You will have to make sure that your code uses different coefficients and states during the second cycle ofthe repeat loop.

stm (num_stages-1),AR1 start_stage ; IIR code goes here banz start_stage,*AR1-

Gain

It may be necessary to add gain to the output of the system. To do this, simply shift the output left (which can be doneusing the ld opcode with its optional shift parameter) before saving the output to memory.

Grading

Your grade on this lab will be split into three parts:

  • 1 point: Prelab
  • 4 points: Code. Your DSP code implementing the fourth-order IIR filter is worth 3 points and the MATLABexercise is worth 1 point.
  • 5 points: Oral quiz. The quiz may cover differences between FIR and IIR filters, the prelab material, and theMATLAB exercise.

Questions & Answers

what is Nano technology ?
Bob Reply
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
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Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
Adin
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Adin
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Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
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research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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Damian Reply
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
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s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
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Source:  OpenStax, Ece 320 - spring 2003. OpenStax CNX. Jan 22, 2004 Download for free at http://cnx.org/content/col10096/1.2
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