Category: 7. Sequential Logic

Toggle Flip-flops are sequential logic circuits frequently used as single bit bistable storage elements in counters, memory divices or as frequency dividers in response to a clock pulse. The Toggle Flip-flop is another type of bistable sequential logic circuit based around the previous clocked JK flip-flop circuit. Toggle flip-flops can be used as a basic digital element…

Flip-flops are the basic building blocks of Sequential Circuits which can be converted from one form to another capable of storing a single bit of data. The conversion of flip-flops from one type to another is not as complicated as you may think. We have seen throughout this Electronics Tutorial section on Sequential Logic that a flip-flop…

The Johnson Ring Counter consists of a number of counters connected together with the output fed back to the input. In this tutorial we will see that the Johnson ring counter is a type of counter created using shift registers, and in the previous Shift Register tutorial we saw that if we apply a serial…

The Shift Register is another type of sequential logic circuit that can be used for the storage or the transfer of binary data. This sequential device loads the data present on its inputs and then moves or “shifts” it to its output once every clock cycle, hence the name Shift Register. A shift register basically consists of several…

The D-type flip-flop is a modified Set-Reset flip-flop with the addition of an inverter to prevent the S and R inputs from being at the same logic level. The D-type Flip-flop overcomes one of the main disadvantages of the basic SR NAND Gate Bistable circuit in that the indeterminate input condition of SET = “0” and RESET…

Multivibrators are sequential logic circuits that operate continuously between two distinct states of HIGH and LOW. Individual Sequential Logic circuits can be used to build more complex circuits such as Multivibrators, Counters, Shift Registers, Latches and Memories. But for these types of circuits to operate in a “sequential” way, they require the addition of some form of…

Sequential Logic Circuits use flip-flops as memory elements and in which their output is dependent on the input state. Unlike Combinational Logic circuits that change state depending upon the actual signals being applied to their inputs at that time, Sequential Logic circuits have some form of inherent “Memory” built in. This means that sequential logic circuits are able to…

The JK Flip-flop is similar to the SR Flip-flop but there is no change in state when the J and K inputs are both LOW. Unlike the JK Flip-flop, the basic S-R NAND flip-flop circuit has many advantages and uses in sequential logic circuits but it suffers from two basic switching problems. Then to overcome…