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Students are to implement and optimize a power spectral density estimator, a pseudo-noise (PN) sequence generator, and an IIR filter.

In this lab you are to implement and optimize the a pseudo-noise (PN)sequence generator, IIR filter, and autocorrelation routines that are part of the previous lab's PSD estimator.For the lab grade, you will be judged on the execution time of your system (memory usage need not be minimized).

Reference implementation

After taking a look at the source code of the PSD estimator reference implementation, youwill likely discover inefficiencies. This implementation is provided as the "reference implementation" of the optimization process and todefine the expected input and output of the application. The computational efficiency of your code will be judged against this implementation.While the given code might serve as a starting point, you should do whatever you need to do to make your code as efficientas possible, while operating in an equivalent manner as the given code.

The exact portion of the code to be optimized is defined below. You may write in C, assembly, or any combination of the two; choosewhatever will allow you to write the fastest code. The optimization process will be smoother if you plan for optimization beforeyou begin any programming.


Since a primary purpose of this lab is to learn optimization and efficient code techniques, your lab grade will be based primarily on the total execution time of your system. You are not required to optimize memory use. Note that by execution time we mean cycle count, not the number of instructions inyour program. Remember that some of the TMS320C55xx instructions take more than one cycle. However, unlike the TMS320C54xx instructions, most operations take only one cycle and can be placed in parallel with other operations. Branch andrepeat statements are the most common instructions that require several cycles to execute. Most C instructions take more than one cycle. The debuggercan be used to determine the exact number of cycles used by your code. The instructions on how to do this can be found in Cycle Counts .

We will grade you based on the number of cycles used between the rand_fillbuffer(); and cfft((DATA *)fft_data,N, SCALE); statements. Thus, you can optimize rand_fillbuffer function but optimizing the fft function will not help. Note that some instructions, like RPT , are non-repeatable instructions ; their use may cause unnecessary glitches in I/O. For grading simplicity, your finalcode should not have modifications except between these two instructions, and M should be set to 31 . If the number of cycles between the two points is variable, the maximumpossible number of cycles will be counted. You must use the dma.c and swi_process.h files in v:\ece420\55x\lab4 as provided by the TAs; these files may not be modified . We reserve the right to test your code by modifying the inputs.

Routine-specific optimization tips

If you are programming the PN generator in assembly, you may wish to refer to the description of assembly instructions forlogical operations in the C55x Mnemonic Instruction Set reference. Initialize the shift register to one. You can debug the PN output bycomparing it to the output of the MATLAB code. Be prepared to prove to a TA that your PN generator works properly as part of your quiz.

Your IIR filtering routine can debugged by writing an impulse followed by zeros in autocorr_in instead of randsample .

Your autocorrelation routine can be debugged by commenting out the IIR-filtering routine and writing the maximum DC value into autocorr_in in a similar manner as described the IIR-debugging step. Note that each of these tips is the most helpful ifthe output is inspected in memory.


Grading for this lab will be a bit different from past labs:

  • 2 points: Working code, implemented from scratch in assembly language or C.
  • 5 points: Optimization. These points will be assigned based on your cycle counts and the optimizations you have made.
  • 3 points: Oral quiz.

Questions & Answers

How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
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 .?
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Stoney Reply
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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.
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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.
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Damian Reply
absolutely yes
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Akash Reply
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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.
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.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Digital signal processing laboratory (ece 420 55x). OpenStax CNX. Jan 18, 2010 Download for free at http://cnx.org/content/col10397/1.10
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