Fundamental of Digital logic

1. Analog vs Digital

Digital computation has the advantage of being precise.
Digital computers are designed for failure rates of much less one in a billion.

2. Transistor
   MOSFET:
   The mechanism used to control flow of electrical current is a semiconductor device known as a transistor. At the lowest level, all digital systems are composed of transistors. In particular, digital circuits use a form of transistor known as a Metal Oxide Semiconductor Field Effect Transistor (MOSFET), abbreviated FET.
   COMS:
   The two forms are known as complementary, and the overall chip technology is known as CMOS (Complementary Metal Oxide Semiconductor).

Propagation delay:
Propagation delay, is a delay occurs between the time an input changes and the output changes.

3. Register
   A register, one of the key components in a processor, is a hardware mechanism that uses a set of latches to store a digital value.

4. Flip-Flops
   A flip-flop is another circuit in which the output depends on previous inputs as well as the current input.
   A flip-flop changes output each time it encounters a one bit. In the example, the transition diagram shows that the flip-flop is only triggered when the input rises. Engineers say that the output transition occurs on the rising edge of the input change; circuits that transition when the input changes from one to zero are said to occur on the falling edge.

5. Binary counter
   A single flip-flop only offers two possible output values: 0 or 1. However, a set of flip-flops can be connected in series to form a binary counter that accumulates a numeric total. Like a flipflop, a counter has a single input. Unlike a flip-flop, however, a counter has multiple outputs. The outputs count how many input pulses have been detected by giving a numerical total in binary.

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6. Clock

Although a clock can be created from an inverter, most clock circuits use a quartz crystal, which oscillates naturally, to provide a signal
at a precise frequency.
The speed of a clock is measured in Hertz (Hz), the number of times per second the clock cycles through a 1 followed by a 0. Most clocks in high-speed digital computers operate at speeds ranging from one hundred megahertz (100 MHz) to several gigahertz (GHz).
For example, at present, the clock used by a typical processor operates at approximately 3 GHz.

7. Decoder/demultiplexor
   The last component, a decoder/demultiplexor, is a single integrated circuit that uses a binary value to map an input to a set of outputs.