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1. Write a verilog code to swap contents of two registers with and without a temporary register?    With temp reg ;always @ (posedge clock)begintemp=b;b=a;a=temp;endWithout te… Read More

Digital Design Interview Questions 1. Design a Transmission Gate based XOR. Now, how do you convert it to XNOR? (Without inverting the output) 2. Design a divide-by-3 sequential circuit with… Read More

Design all Combinational Gates Using 2:1 MuxDesign full adder using 2:1 and 4:1 MuxDesign Half adder using 2:1 and 4:1 Mux  Design full subtractor using 2:1 and 4:1 Mux Design… Read More

The previous lessons have shown how to use channels with files and blocking sockets. Tcl also supports non-blocking reads and writes, and allows you to configure the sizes of the I/O buffers… Read More

The previous lessons have shown how to use channels with files and blocking sockets. Tcl also supports non-blocking reads and writes, and allows you to configure the sizes of the I/O buffers… Read More

For most applications, a single interpreter and subroutines are quite sufficient. However, if you are building a client-server system (for example) you may need to have several interpreters… Read More

The clock command provides access to the time and date functions in Tcl. Depending on the subcommands invoked, it can acquire the current time, or convert between different represe… Read More

Tcl I/O is based on a the concept of channels. A channel is conceptually similar to a FILE * in C, or a stream in shell programming. The difference is that a channel may be a eithe… Read More

The simplest method of making a script run faster is to buy a faster processor. Unfortunately, this isn't always an option. You may need to optimize your script to run faster. This is diffic… Read More

Scripts are much more useful if they can be called with different values in the command line.For instance, a script that extracts a particular value from a file could be written so that it p… Read More

When you are debugging Tcl code, sometimes it's useful to be able to trace either the execution of the code, or simply inspect the state of a variable when various things happen to it. The&n&hell…Read More

In previous lessons we discussed how the return command could be used to return a value from a proc. In Tcl, a proc may return a value, but it always returns a status.When a Tcl co… Read More

Tcl also supports commands to change and display the current working directory.These are:cd ?dirName?Changes the current directory to dirName (if dirName is given, o… Read More

The Tcl interpreter does only one substitution pass during command evaluation. Some situations, such as placing the name of a variable in a variable, require two passes through the substitut… Read More

There may be some unexpected results when you try to compose command strings for eval.For instanceeval puts OKwould print the string OK. However,eval puts Not OKwill generate an error.T… Read More

One difference between Tcl and most other compilers is that Tcl will allow an executing program to create new commands and execute them while running.A tcl command is defined as a list of st… Read More

The previous lesson showed how the source command can be used to separate a program into multiple files, each responsible for a different area of functionality. This is a simple an… Read More

The source command will load a file and execute it. This allows a program to be broken up into multiple files, with each file defining procedures and variables for a particular are… Read More

The info command includes a set of subcommands that will provide all the info you could want about a proc. These subcommands will return the body of a proc, the arguments to the pr… Read More

There are a number of subcommands to the info command that provide information about the current state of the interpreter. These commands provide access to information like the cur… Read More

Tcl provides a number of commands for introspection - commands that tell what is going on in your program, what the implementation is of your procedures, which variables have been… Read More

So far the lessons have dealt with programming within the Tcl interpreter. However, Tcl is also useful as a scripting language to tie other packages or programs together. To accomplish this… Read More

There are two commands that provide information about the file system, glob and file.glob provides the access to the names of files in a directory. It uses a name matchin… Read More

Tcl provides several methods to read from and write to files on disk. The simplest methods to access a file are viagets and puts. When there is a lot of data to be read, however, i… Read More

Tcl arrays are collections of variables, rather than values. This has advantages in some situations (e.g., you can use variable traces on them), but also has a number of drawbacks:They canno… Read More