Introduction to HDL Prelim 2

Digital circuit

Designed by using some IC

Combinational logic

A digital circuit whose output depends only on the current inputs.

Multiplexers

Circuits that can select one of many values based on the selection input.

Decoder

Converts a binary (encoded) value into a one- hot representation.

Encoder

Are the opposite of decoders. They convert a one-hot value into a binary representation.

Arbiter

A set of inputs and then outputs a one- or-none-hot value

Sequential logic

A type of circuit whose output depends the current inputs and the sequence of previous inputs.

Event-Driven

Asynchronous circuits that change state immediately when enabled.

Clock Driven

Synchronous circuits that are synchronized to a specific clock signal.

Pulse Driven

A combination of the two that responds to triggering pulses.

Clock

A signal that toggles between 0 and 1 with a set frequency.

Feedback Loop

The two inverters or NOT gates are connected in series, with the output at Q fed back to the input.

Latches

Basic storage elements that operate with signal levels (rather than signal transitions).

Flip-flop

A circuit that maintains a state until directed by input to change the state.

Counters

Used in digital electronics for counting purposes. They can count specific events happening in the circuit. They can also be designed with the help of flip flops.

Verilog

A textual format for describing electronic circuits and systems. It is intended to be used for verification through simulation, timing analysis, test analysis, and logic synthesis.

Behavioral level

This level describes a system by concurrent algorithms (Behavioral). Every algorithm is sequential, which means it consists of a set of instructions that are executed one by one. Functions, tasks, and blocks are the main elements.

Register-transfer level

Designs using this level specify the characteristics of a circuit using operations and the transfer of data between the registers.

Gate level

The characteristics of a system are described by logical links and their timing properties.

Token

Consists of one or more characters and every single character.

White Space

It can contain characters for spaces, tabs, new-lines, and form feeds.

Multiline comments

Begin with the token "/*" and end with the token "*/". (forward slash and asterisks)

Identifiers

It is the name used to define the object, such as a function, module, or register.

Operators

These are special characters used to put conditions or to operate the variables.
Ex: >,+,", &! =

Keywords

Words that have special meaning in Verilog. It includes compiler directives and system tasks and functions.

Gate Primitives

The basic logic gates using one output and many inputs are used in Verilog.

Transmission Gate Primitives

These primitives include both buffers and inverters.