Sequential Circuit Digital Logic and Computer Design by Ravinder Nath Rajotiya - October 18, 2023October 25, 20230 Introduction In the previous posts we have focused on the design of many combinational circuits. The outputs in those circuits were dependent on the inputs applied at that instant of taking the output. Examples of such circuits were adders like half and full adders, half and full subtractors, BCD adders, Multiplexers, decoders , etc. But what if we have to add say 5, 10 or even more numbers. Practically we only two numbers at a time, store the partial result in our memory and then add this partial result(memory content) with the next numbers to get next partial sum and so on till all the numbers have been added. To save the partial results we need memory device. Such types of circuits
Flip-Flop and Latches Digital Logic and Computer Design by Ravinder Nath Rajotiya - October 9, 2023October 9, 20230 Introduction The second type of digital circuitry are the sequential circuits. These circuitry are formed as a combination of combinational and the memory element. The memory element stores the state of the circuit. We start discussing on Latches and Flip-Flops. Latches Storage elements that operate with signal levels (i.e. level triggered of signal input) are termed as latches. A latch is a bi-stable element having two states Q and Q’. It is a sequential circuit that will continuously change its state as soon as the input changes without waiting for the clock signal. A latch usually has an enable input. When the enable is active the output changes as soon as there is a change in the inputs. Latches are not of practical