microprocessor based digital filter

1. TAE-1
Subject:
Self Study
“Activity Based Learning”
Topic
“Microprocessor Based Digital Filter”

2. Teacher Assessment Exam-1
Department Of Electronics and Tele-Communication Engineering
(2015-2016)
3rd Year | 5th Semester ©
Subject- Self Study
“Activity Based Learning”
To p i c :
“Microprocessor Based Digital Filter”
S u b m i t t e d B y :
Ashish Pandey (30)
G u i d e d B y :
Prof. Kamlesh Kalbande,
Ass. Proff, E&TC Department,
G.H.R.C.E., Nagpur.

3. Introduction to Digital Filter
• Digital filter is a system that performs mathematical
operations on a sampled, discrete-time signal to
reduce or enhance certain aspects of that signal.
• Digital filters are used for two general purposes:
(1) Separation of signals that have been combined.
(2) Restoration of signals that have been distorted in
some way.

4. Introduction to Microprocessor
• A microprocessor is an electronic component that is used by
a computer to do its work.
• It is a central processing unit on a single integrated circuit chip
containing millions of very small components
including transistors, resistors, and diodes that work together.
• Microprocessors help to do everything from writing to
searching the Web.
• Everything a computer does is described by lots of precise
instructions, and microprocessors carry out these instructions
at incredible speed—many millions of times a second.

5. Abstract
• The relation between the performance of digital filters
and some inherent characteristics of the latest
microprocessors.
• The implementation of digital filters on
microprocessor(s) offers some advantages, but at the
same time imposes limits on the speed, accuracy or
even stability of digital filters.
• Parallel processing technique implemented on
multi—microprocessor structures is considered as an
alternative to significantly improve the filter
performances.

6. Objectives
• The objective is to investigate the design and to carry out
the actual implementation of microprocessor-based Digital
filters which may be suitable for various identification
purposes.
• The procedure is based on bilinear transformation
technique with emphasized consideration on the
compensation of frequency and on the choice of the ratio of
working frequency to sampling frequency.
• The effectiveness of the proposed design procedure will be
demonstrated by several examples.
• It is remarked that the potential of the procedure may be
enhanced by microprocessor based digital filter design
techniques.

7. Goals to Design Microprocessor
Based Digital Filter
• The main goal of the paper is to find a
methodology to study the implementation of
digital filters on microprocessors.

8. Microprocessors characteristics
• The most important factors which influence the
microprocessor performances are the technology and
the hardware architecture and the instruction set.
• The technology is the basic factor which imposes
limitation on speed, packing density and power
consumption.
• Microprocessor architecture has evolved from single
core processors to multi-core processors. Processors
with two or more cores are faster because they can
process multiple pieces of information simultaneously.
• The instruction set contains logic operations, data
transfers, program control instructions.

9. • The First Generation Microprocessor.
• The Second Generation Microprocessor.
• The Third Generation Microprocessor.
Microprocessors characteristics

10. First generation Microprocessor for
Digital Filter
It is among which employed the p—channel MOS
technology. (Intel 8008)
We ignore this processors because of low
performances when compared with other newer
processors.

11.  It is among which employed the n—channel MOS
processor. (Intel 8080,Motorola 6800, F—8, Zilog
Z—80, etc. )
 This is 8 bit data bus and address directly up to 64 K
bytes of memory.
 This made possible the utilization of only one +5 V
power supply and the increase of processing speed.
Second generation Microprocessor
for Digital Filter

12. • It is called as 16—bit microprocessors (Intel 8080,
8086, 8087) which use H—MOS and have improved
architectures and enhanced instruction sets.
• It can perform in hardware operations such as
multiply, add, divide, square root, tangent and
exponentiation.
• The clock speed was considered to be 2 MHZ for
8080 and 5 MHZ for 8086 and 8087.
• In addition to increasing the clock speed up to 8
MHZ, pipeline architecture was used.
Third generation Microprocessor for
Digital Filter

13. DESIGN OF DIGITAL FILTERS
• The basic steps in the design of digital filters
generally involve:
• The specification on the general characteristics
of the filters.
• The approximation and design consideration in
attaining the specification.
• The realization of the filters using finite
precision arithmetic.

14. ERROR ANALYSIS
• When signals are represented by numbers inside the
processor, a quantization effect takes place.
• In recursive filters, this effect is removed and amplified by
the closed loops.
• Nonlinearities such as quantization noise, limit cycles and
overflow are therefore introduced.
• When signals are represented on microprocessors with fixed
point arithmetic we have the choice to use integers or
numbers between —1 and +1.
• An expression is derived for the power of the round—off
(RO) noise at the output of a filter is based on statistical
arguments. The variance of the noise error is given by:

15. Working Diagram

16. RELATIONSHIP BETWEEN THE
PERFORNANCES OF DIGITAL FILTERS AND
MICROPROCESSOR CHARACTERISTICS
N1
8086 — Single precision
Computational Time and Error Vs. Filter Order
Filter Order

17. 8086 — Double precision
Computational Time and Error Vs. Filter Order
RELATIONSHIP BETWEEN THE
PERFORNANCES OF DIGITAL FILTERS AND
MICROPROCESSOR CHARACTERISTICS

18. Conclusion
• It is reminded that the microprocessor-based
filters can readily be tuned, by adjusting the
sampling frequency w , so that the critical
frequencies coincide with the desired
specifications

19. REFERENCES
• A. V. Oppenheim and R. W. Schafer, "Digital
Signal Processing," Prentice—Hall, Inc.,
Englewood Cliffs, New Jersey, 1975.
• L. Altman, editor, "Microprocessors,“
Electronics Book Series, McGraw—Hill Co.,
New York, 1975.
• ieeexplore.ieee.org