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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.


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-


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.


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 the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
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
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
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.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
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
characteristics of micro business
for teaching engĺish at school how nano technology help us
How can I make nanorobot?
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
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
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.
what is the actual application of fullerenes nowadays?
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.
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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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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