"&" operator is not synthesized by VHDL synthesis tool.
Various synthesis tools are provided by vendors like XILINX, CADENCE, SYNOPSIS. Details are available at their websites.
VHDL is a text based programming language.
A function is a subprogram written in VHDL. This program can be called and used in other programs.
After compiling a hardware description language like VHDL, it is required to apply inputs to the program in order to obtain out puts. Applying the inputs involves initial conditions. As the systems designed using VHDL are electronic, the initial conditions plays a vital role. Hence, all these conditions along with the information as to where the input is expected to change from 1 to 0 or 0 to 1 is provided to the VHDL program. This is done in the form of a wave or another VHDL program. These are called VHDL test benches. In other words, test benches are the means of applying inputs to VHDL program.
A Test Bench in VHDL is code written in VHDL that provides stimulus for individual modules (also written in VHDL). Individual modules are instantiated by a single line of code showing the port connections to the module. The correctness of the written program can be checked by writing the test bench. It is a collection of VHDL procedures and functions which allow the user to create their own scripting instructions for test stimulus. Designers manually design their test bench inputs to checks the output. The stimulus script or test case contains the instructions in a regular ASCII text file. The test bench VHDL package contains procedures to create instructions, read, parse and execute the test script.
Various synthesis tools are provided by vendors like XILINX, CADENCE, SYNOPSIS. Details are available at their websites.
Douglas E. Ott has written: 'A designer's guide to VHDL synthesis' -- subject(s): VHDL (Computer hardware description language)
In the synthesis part of a VHDL code, the EDA tool provides technology schematic. It describes the structure and sub-structures of the design. We can watch our design from the system level to the gate level.
A virtual calculator can be implemented using VHDL. We call it VHDL calculator.
In the "architecture" of VHDL, after "begin" statement, if you want, you can apply the inputs. For example, a<='0'; b<='1'; etc. But, if you want the inputs to change periodically, then you should at least apply one "enable" or "clock" pulse.
VHDL is the VHSIC Hardware Description Language. VHSIC is an abbreviation for Very High Speed Integrated Circuit. It can describe the behaviour and structure of electronic systems, but is particularly suited as a language to describe the structure and behaviour of digital electronic hardware designs, such as ASICs and FPGAs as well as conventional digital circuits. VHDL is an international standard, regulated by the IEEE. Simulation and synthesis are the two main kinds of tools which operate on the VHDL language. VHDL allows designs to be described using any methodology - top down, bottom up or middle out! VHDL can be used to describe hardware at the gate level or in a more abstract way.
VHDL provides conversion functions and resolution functions.
vhdl code for binary to Hexadecimal ?
VHDL is a text based programming language.
vhdl code for ascending order of numbers
A function is a subprogram written in VHDL. This program can be called and used in other programs.
VHDL is a hardware description language. It describes the functionality of a hardware as a program. If we know the architecture of 8085, the same can be implemented or coded using VHDL.