flip-flop

A flip-flop is a device very much like a latch in that it is a bistable multivibrator, having two states and a feedback path that allows it to store a bit of information. The difference between a latch and a flip-flop is that a latch is asynchronous, and the outputs can change as soon as the inputs do (or at least after a small propagation delay). A flip-flop, on the other hand, is edge-triggered and only changes state when a control signal goes from high to low or low to high. This distinction is relatively recent and is not formal, with many authorities still referring to flip-flops as latches and vice versa, but it is a helpful distinction to make for the sake of clarity.
There are several different types of flip-flop each with its own uses and peculiarities. The four main types of flip-flop are : SR, JK, D, and T










Qn,0,1, ivalid value out put  of function S,R

D- Flip Flop


We remember that a simple SR flip-flop requires two inputs, one to “SET” the output and one to “RESET” the output. By connecting an inverter (NOT gate) to the SR flip-flop we can “SET” and “RESET” the flip-flop using just one input as now the two input signals are complements of each other. This complement avoids the ambiguity inherent in the SRlatch when both inputs are LOW, since that state is no longer possible.
Thus this single input is called the “DATA” input. If this data input is held HIGH the flip flop would be “SET” and when it is LOW the flip flop would change and become “RESET”. However, this would be rather pointless since the output of the flip flop would always change on every pulse applied to this data input.


Comments

Post a Comment

Popular posts from this blog

WHAT ETHICAL, SOCIAL, AND POLITICAL ISSUES ARE RAISED BY INFORMATION SYSTEMS?

Image
Information technology is introducing changes for which laws and rules of acceptable conduct have not yet been developed. Increasing computing power, storage, and networking capabilities--including the Internet--expand the reach individual and organizational actions and magnify their impacts. The ease and anonymity with which information is now communicated, copied, and manipulated in online environments pose new challenges to the protection of privacy and intellectual property. The main ethical, social, and political issue raised by information systems center around information rights and obligations, property rights and obligations, accountability and control, system quality, and quality of life. 1.Ethical issues:  Intellectual property rights, electronic monitoring of employees and data utilization; 2.Cultural issues:  Assimilation of emerging technologies, developing trust, power asymmetry, policy implementation, and social environments; 3.Human interaction i...
Read more

Porter’s Value Chain Analysis

Image
What is a Value Chain Analysis? The value chain also known as Porter’s Value Chain Analysis is a business management concept that was developed by  Michael Porter . In his book  Competitive Advantage  (1985),  Michael Porter  explains Value Chain Analysis; that a value chain is a collection of activities that are performed by a company to create value for its customers.   Value Creation  creates added value which leads to competitive advantage. Ultimately, added value also creates a higher profitability for an organization. Porter’s Value Chain Analysis The strength of the Porter’s Value Chain Analysis is its approach. The Porter’s Value Chain Analysis focuses on the systems and activities with customers as the central principle rather than on departments and accounting expense categories. This system links systems and activities to each other and demonstrates what effect this has on costs and profit. Consequently, it (Value Chain Analysis) ma...
Read more

General Register organization & Components of CPU and their functions:

Image
Components of CPU and their functions: CPU or  Central processing unit  is the brain of the computer system. Functions of CPU varies from data processing to controlling input-output devices. Each and every instruction no matter how complex or simple, it has to go through the CPU. In this article we will learn various components of CPU and their functions. So, let us say we press a key on the keyboard and it instantly appears on our computer monitor so the CPU of the computer is what makes this possible. The central processing unit is also responsible for storing data or information, intermediate results and instructions in the memory system. It also controls the operations of all other parts of the computer system. Functions of a CPU: CPU generally performs the arithmetical and logical operations, controlling of different input-output devices. These operations are performed based on some predefined algorithm...
Read more