The concept: methods – content – objectives - Signals, Processes, and Systems - page 18

Preliminary conclusions: the concept takes on clearer contours
All the facts, propositions and arguments advanced so far would be useless if it were not
possible to extrapolate a clear and up-to-date concept which will be valid in the future -
a concept which will be valid many years from now and which is convincing in its
simplicity. Like the thesis formulated on the first page: microelectronics does nothing else
but signal processing!
• The huge number of discrete analog circuits will in future no longer be state of the art
and is therefore not dealt with here. Thus the multi-function board represented in
Illustration 13: shows that analog technology will at most remain in existence at the
beginning (source) and end (drain) of a communications system. The "core" of the
system is purely digital. There are exceptions only in the field of high and maximum
frequency, for instance, on the actual path of transmission.
• The entire (digital) hardware - as the example of the multi-function board in Illustra-
tion 13: again shows - consists of only a small number of chips (A/D, D/A conver-
sion, multiplexer, timer, memory etc and above all a processor). In future more and
more of these components will be integrated on a single chip . This is already the case
with many microcontrollers, indeed with entire systems. It cannot therefore be the
aim of this manuscript to discuss in detail an infinite or even a large number of differ-
ent IC chips. In future they will no longer exist. Hardware will, therefore, in the fol-
lowing always be presented as a block diagram (see Illustration 13:). This block
diagram consists of standard components/circuits which are linked with each other.
We shall refer to this kind of block diagram as a hardware block diagram (H block
diagram) .
• The (digital) hardware has the task of providing the processor (computer) with the
measurement data or signals in a suitable form. The program contains the signal
processes in algorithmic form. What the processor does with the data is determined
by the program. The "intelligence" of the overall system lies in the software. As recent
development shows, software can largely replace hardware. Algorithms instead of
circuits! Thus only a few standard components remain even for digital hardware.
• Programs for the processing of signals will presumably no longer be represented as a
"cryptic code" but also as a block diagram.This shows the order and linking of the
processes to be carried out. The block diagram can be programmed graphically on the
screen and produces in the background the source code in a certain program language
(e.g.C++).
• We shall refer to block diagrams of this kind as signal block diagrams (S block
diagram) . Almost all the signal systems illustrated in this topic are S block diagrams,
behind which virtual systems are concealed. They were above all generated by means
of DASY Lab .
• The actual signal processes are to be understood by means of the pictorial comparison
of the input and output signal (in the time and frequency domain). In this way it is
possible to see how the process has changed the signal.
The essential forms of representation used in this topic have now been described. They
are of a visual nature and are in keeping with the human capacity for thinking in pictures.