3. Digital Signal Processor
M & I 3-10-2012
A large number of mathematical operations must be
performed quickly and repeatedly on a set of data by DSP.
Signals are constantly converted from analog to digital,
manipulated digitally, and then converted back to analog form.
Higher power consumption and size of a DSP
implementation may make it unsuitable for small- size
applications.
4. Digital Signal Processor
M & I 3-10-2012
In addition to performing mathematical
calculations very rapidly, DSPs must also have a
predictable execution time.
5. Digital Signal Processor
M & I 3-10-2012
1. Digital signals do not corrupted by noise , minimam
electromagnetic interference etc.
2. Digital signals typically use less bandwidth .So , that
you can fill more information into the same space.
3. Digital can be encrypted so that only the intended
receiver can decode it .(like secure telephone system etc.)
5. It is more secure and less costly.
6. It is easier to translate human audio and video
signals and other messages into machine language.
6. Digital Signal Processor
M & I 3-10-2012
6. Enables transmission of signals over a long
distance.
7. Digital signal processing techniques are more
advanced and this technique is also use for Digital TV
Transmission .
7. Digital Signal Processor
M & I 3-10-2012
• Before few years it is seen that general purpose
computers are capable of performing
two major tasks.
(1) Data Manipulation, and
(2) Mathematical Calculations
• All the microprocessors are capable of doing these
tasks but it is difficult to make a device which can
perform both the functions optimally(under a particular
set of circumstances.).
9. Digital Signal Processor
M & I 3-10-2012
Microprocessors are built for a general purpose
functions, and normally run large blocks of software,
such as operating systems like Windows or UNIX.
Although today's microprocessors, including the
Intel family, are extremely fast or faster than some
DSPs they are still not often called upon to perform
real-time computation or signal processing.
10. Digital Signal Processor
M & I 3-10-2012
Usually, their high processing power is directed
more at handling many tasks at once, and controlling
huge amounts of memory and data, and controlling a
wide variety of computer peripherals (disk drive,
modem etc).
However, microprocessors such as Intel are well
known for their size, cost, and power consumption to
achieve their muscular performance.
Using EXCEL spreadsheet software can assist in
manipulating the data and making graphs quickly.
11. Digital Signal Processor
M & I 3-10-2012
whereas DSPs are more designed for a specific
purpose, a smaller range of functions at lightning
speed, yet less costly and requiring much less space
(size) and power consumption to achieve their purpose.
In computer systems, DSPs may be employed as
attached processors, assisting microprocessor.
DSP is use for Image Processing, Biomedical Signal
Analysis(ex. X-rays), Telecommunications Products
(ex. Bluetooth).
12. Digital Signal Processor
M & I 3-10-2012
DSP applications were implemented using bit-slice processors(Bit
slicing is a method of combining processor modules to multiply the
word length).
These bit slice architectures would sometimes include a peripheral
multiplier chip which included an accumulator, providing the
multiply–accumulate (MAC) function.
multiply–accumulate operation is a common step that computes
the product of two numbers and adds that product to an
accumulator.
13. Digital Signal Processor
M & I 3-10-2012
In a bit-sliced processor, each module contains an
ALU(arithmetic-logic unit) usually capable of handling a
4-bit field. By combining two or more identical modules, it is
possible to build a processor that can handle any multiple of
this value, such as 8 bits, 12 bits, 16 bits, 20 bits, and so on.
Each module is called a slice. The control lines for all the
slices are connected effectively in parallel to share the
processing "work" equally.
14. Digital Signal Processor
M & I 3-10-2012
1978 Texas Instruments produced the first Speak & Spell, TMS5100
the industry's first digital signal processor.
In 1978, Intel released the 2920 as an "analog signal processor". It had
an on-chip ADC/DAC with an internal signal processor, but it didn't
have a hardware multiplier and was not successful in the market.
In 1980 the first stand-alone, complete DSPs – the NEC µPD7720and
AT&T DSP1.
15. Digital Signal Processor
M & I 3-10-2012
The NEC µPD7720 runs at 4 MHz frequency with 128-word data
RAM, 512-word(used BCD rather than plain binary, typically having a
word size of 10 or 12 decimal digits) data ROM, and 512-word program
memory, which has VLIW like instruction format; enabling all of ALU
operation, address register increment/decrement operation, and move
operation in one cycle.
The Altamira DX-1 was another early DSP, utilizing quad integer
pipelineswith branch prediction(part of a processor that determines
whether a conditional(false if first instruction is false from two
instruction) branch (jump) in the instruction flow of a program is likely
to be taken or not).
16. Digital Signal Processor
M & I 3-10-2012
Another DSP produced by Texas Instruments(TI), the TMS32010
presented in 1983 success. It was based on the Harvard architecture. It
already had a special instruction set, with instructions like load-and-
accumulate or multiply-and-accumulate. It could work on 16-bit
numbers and needed 390 ns for a multiply–add operation. TI is now the
market leader in general-purpose DSPs.
17. Digital Signal Processor
M & I 3-10-2012
About five years later, the second generation of DSPs began to
spread. They had hardware to accelerate tight loops(Such a loop which
heavily uses I/O or processing resources, failing to sufficient share them
with other programs running in the operating system). Some of them
operated on 24-bit variables and a typical model only required about 21
ns for a MAC. Members of this generation were for example the AT&T
DSP16A or the Motorola DSP56001.
18. Digital Signal Processor
M & I 3-10-2012
The main improvement in the third generation was the appearance of
application-specific units and instructions in the data path, or sometimes
as coprocessors. These units allowed direct hardware acceleration of
very specific but complex mathematical problems, like the Fourier-
transform or matrix operations. Some chips, like the Motorola MC68356,
even included more than one processor core to work in parallel. Other
DSPs from 1995 are the TI TMS320C541 or the TMS 320C80.
The fourth generation is best characterized by the changes in the
instruction set and the instruction encoding/decoding. SIMD extensions
were added, VLIW and the superscalar architecture appeared. As always,
the clock-speeds have increased, a 3 ns MAC now became possible.
19. Digital Signal Processor
M & I 3-10-2012
Digital Signal Processor
M & I 3-10-2012
They are found in cellular phones, computer
devices, fax/modems , disk drives, radio ,
printers, MP3 players, high-definition
television(HDTV), digital cameras, and so on.
21. Digital Signal Processor
M & I 3-10-2012
•An AIC23 stereo codec(provides ADC AND DAC functions.)
• 16 Mbytes of synchronous DRAM
• 512 Kbytes of non-volatile Flash memory (256 Kbytes usable in
default configuration)
• 4 user accessible LEDs and DIP switches
•Standard expansion connectors for daughter card use
• JTAG emulation through on-board JTAG(Joint Test Action Group )
emulator with USB host
interface or external emulator
• Single voltage power supply (+5V)
