Download
1 / 13
0 likes | 1 Views
Latches and flip-flops are basic memory elements in digital electronics. Latches are level-triggered and store data instantly, while flip-flops are edge-triggered and change state only on clock pulses. Common flip-flops include SR, D, JK, and T types.<br><br>Digital circuits are classified as combinational (outputs depend only on current inputs, e.g., adders, multiplexers) and sequential (outputs depend on current inputs and past states, e.g., counters, registers). These elements form the foundation of modern digital systems.
E N D
Flip Flop, Latches, Combinational and Sequential Circuit Dr Anita Choudhary Assistant Professor Department of Computer Science anitach312@gmail.com
Flip-flop • Flip-flop is a basic digital memory circuit, which stores one bit of information. • Flip flops are the fundamental blocks of most sequentialcircuits. • Flip-flops are used as memory elements in sequential circuits. • The state of flip-flops changes at the active state of clock pulses and remains unaffected when the clock pulse is not active. • The output value depends on the previous input signals and the current state of the flip-flop. This is why a flip-flop is also called a bistablemultivibrator.
Types of Flip-Flops • There are different types of flip-flops with different characteristics and applications. Some of the common types of flip-flops are: • SR Flip-Flop: This is the simplest type of flip-flop that has two inputs: S (set) and R (reset). • JK Flip-Flop (Jack Kilby flip-flop): This is an improved version of the SR flip-flop that eliminates the invalid state by using feedback connections. • D Flip-Flop: This is a simple type of flip-flop that has only one input: D (data). The output value of the flip-flop follows the input value (Q = D). • T Flip-Flop: This is a special type of JK flip-flop that has only one input: T (toggle). When T is 1, the flip-flop toggles its state (Q becomes Q’ and Q’ becomes Q).
Latch • Latch is an electronic device, which changes its output immediately based on the applied input. • It is used to store either 1 or 0 at any specified time. • It consists of two inputs namely “SET” and “ RESET ” and two outputs, which are complement to each other.
Edge Triggered • In edge triggering, the input signal’s sharp edge, which is picked up by the circuit’s clock signal, triggers the signal change. • The trigger edge is this abrupt edge, and depending on how the circuit is constructed, it may be rising or dropping. • The circuit reacts by switching the output signal to the opposing state when it detects the trigger edge.
Level Triggered • level triggering is a category of triggering mechanism that is based on the detection of a particular signal level. • It is applied when detecting the input signal level at a specific moment rather than a change in state is required. • In applications like data acquisition and control systems, where continuous monitoring of an input signal is necessary, level triggering is frequently utilized.
Sequential Circuit • A sequential circuit is specified by a time sequence of inputs, outputs, and internal states. • The output of a sequential circuit depends not only on the combination of present inputs but also on the previous outputs. • Unlike combinational circuits, sequential circuits include memory elements with combinational circuits. • Some examples are counters and shift registers.
Combinational Circuit • These circuits are developed using AND, OR, NOT, NAND, and NOR logic gates. These logic gates are building blocks of combinational circuits. • A combinational circuit consists of input variables and output variables. Since these circuits are not dependent upon previous input to generate any output. • A combinational circuit can have an n number of inputs and m number of outputs. • In combinational circuits, the output at any time is a direct function of the applied external inputs.
