Output is determined by the current state and the input. The output is fed back to the input to determine the next output.
Generates a series of pulses at regular intervals. Used to synchronize the operation of digital circuits.
Clock signal
Section titled “Clock signal”A square wave with a 50% duty cycle. The signal is high for half the period and low for the other half.
Triggering methods
Section titled “Triggering methods”Determines when the output changes according to the clock signal.
Positive edge-triggered
Section titled “Positive edge-triggered”Output changes on the rising edge of the clock signal.
Negative edge-triggered
Section titled “Negative edge-triggered”Output changes on the falling edge of the clock signal.
Level Triggering
Section titled “Level Triggering”Output changes when the clock signal is high (or low).
Characteristics
Section titled “Characteristics”Characteristic table
Section titled “Characteristic table”A table of memory, current input and output. Similar to a truth table.
Excitation table
Section titled “Excitation table”A table used to determine the required inputs for a sequential circuit element to transition from its current state to a desired next state. Provides a mapping between the current state, next state, and the necessary inputs. Essential for designing and analyzing sequential circuits.
Latch & Flip-flop
Section titled “Latch & Flip-flop”A memory element that can store a bit.
Level triggered. Independent of a clock. Asynchronous. Can change state while enabled.
Flip-flop
Section titled “Flip-flop”Edge triggered. Dependent on a clock. Synchronous. Can change state only at rising edge of clock.
Types of sequential circuits
Section titled “Types of sequential circuits”Asynchronous
Section titled “Asynchronous”Works without a clock. Built using latches.
Synchronous
Section titled “Synchronous”Works based on a clock. Built using flip flops.