Electronică digitală

Introduction.

Digital electronics is a part of electronics that is responsible for electronic systems in which information is encoded in only two states. In these states can be called"true" or "false", or more commonly 1 and 0, meaning that in a digital electronic circuit there are two voltage levels.

Electronically assigned each a voltage or voltage range given, which are calledlogical levels, typical of all digital signal. Usually the voltage values in electronic circuits can be varied between 1.5, 3, 5, 9 and 18 volts depending on the application, and for example in a conventional transistor radio voltage voltages areusually 5 and 12 volts as in the computer hard drives IDE.

It differs from that analog electronics, digital electronics for a voltage valueencodes one of two states, while for the analog electronics is an infinite number ofstates to encode information according to the voltage.

This feature allows, using Boolean algebra (binary logic) and the binary numbering system, can perform complex arithmetic or logical operations (calculations) on the input signals, very expensive to make using analog methods.

Digital systems can be classified as follows:

- wired systems:

combinational

sequential

memoirs

Converters

- programmed systems:

microprocessors

microcontrollers.

**// in our case we speak of wired systems sequential circuit //**

2. Analysis and synthesis of sequential logic.

2.1.

The general structure of a sequential circuit.

outputs of a sequential switching circuit can be generally expressed as Boolean functions of its inputs and internal state:

Transition table of a sequential circuit (automat Mealy).

Transition table of an automat Moore.