Review: combinatorial circuits
 

  • There are 2 types of digital circuits:

      • Combinatorial circuits: the output values are determined (completely) by the (current) input values

      • Sequential circuits: the output values are determined by the (current) input values and the (current) state of the circuit

We have only studied combinatorial circuits so far...

Review: combinatorial circuits

Example of a combinatorial circuit - 4 bit multiply circuit

The product (output) is completely determined by the input numbers (e.g.: 0010 × 0010 = 0100))

Intro to sequential circuits
 

  • Some digital circuits has a state

    (I will show you such a circuit soon).

  • The state of the (digital) circuit will allow the circuit to remember information

    In fact, memory circuits are sequential circuits !!

  • The state of a sequential circuit is always some output of the digital circuit !