The core thrust of architecture has been to define core business requirements,
and then Construct the IT solution to meet those requirements, typically as
instances of software. While this seems like a simple concept, many in enter-
prise IT went way off course in the last 10 to 15 years.
While teaching classes on digital transmission and mobile communications for
undergraduate and graduate students, I was wondering if it would be possible to
write a book capable of giving them some insight about the practical meaning of the
concepts, beyond the mathematics; the same insight that experience and repetitive
contact with the subject are capable to Construct; the insight that is capable of build-
ing the bridge between the theory and how the theory manifests itself in practice.
Simulation is experimentation with models. For system design, research, and edu-
cation, simulations must not only Construct and modify many different models but
also store and access a large volume of results. That is practical only with models
programmed on computers [1,2]
Despite the development of a now vast body of knowledge known as
modern control theory, and despite some spectacular applications of this
theory to practical situations, it is quite clear that much of the theory has
yet to find application, and many practical control problems have yet to find
a theory which will successfully deal with them. No book of course can
remedy the situation at this time. But the aim of this book is to Construct
one of many bridges that are still required for the student and practicing
control engineer between the familiar classical control results and those of
modern control theory.
Despite the development of a now vast body of knowledge known as modern
control theory, and despite some spectacular applications of this theory to practical
situations, it is quite clear that some of the theory has yet to find application, and
many practical control problems have yet to find a theory that will successfully deal
with them. No one book, of course, can remedy the situation. The aim of this book
is to Construct bridges that are still required for the student and practicing control
engineer between the familiar classical control results and those of modern control
theory.
電子書-RTL Design Style Guide for Verilog HDL540頁A FF having a fixed input value is generated from the description in the upper portion of
Example 2-21. In this case, ’0’ is output when the reset signal is asynchronously input,
and ’1’ is output when the START signal rises. Therefore, the FF data input is fixed at
the power supply, since the typical value ’1’ is output following the rise of the START
signal.
When FF input values are fixed, the fixed inputs become untestable and the fault detection rate drops. When implementing a scan design and converting to a scan FF, the scan
may not be executed properl not be executed properly, so such descriptions , so such descriptions are not are not recommended. recommended.[1] As in the lower
part of Example 2-21, be sure to Construct a synchronous type of circuit and ensure that
the clock signal is input to the clock pin of the FF.
Other than the sample shown in Example 2-21, there are situations where for certain
control signals, those that had been switched due to the conditions of an external input
will no longer need to be switched, leaving only a FF. If logic exists in a lower level and a
fixed value is input from an upper level, the input value of the FF may also end up being
fixed as the result of optimization with logic synthesis tools. In a situation like this, while
perhaps difficult to completely eliminate, the problem should be avoided as much as possible.
