Sequential Circuits: Clocks

Before we describe how each flip-flop type works in details, we first need to introduce the concept of a clock.

The clock is a timing device that generates pulses to synchronize changes in a sequential circuit. It tells flip-flops when to update their states.

This signal is typically a square wave that alternates between high (1) and low (0) states at a specific frequency, coordinating all circuit operations to prevent data errors. The next slide contains a diagram showing these clock waves.

The clock is built using an oscillator sequential circuit, commonly based on quartz crystals or RC (resistor-capacitor) circuits to generate consistent timing pulses.

• A quartz oscillator or RC circuit generates a regular signal, which can then be shaped into a square wave using additional circuitry to ensure precise timing.