Memory Cell Is Useful Concept For EC Student.
* Use *
Cell Will Store Binary Value 1 Or 0 .
There Are Two Signle .
1. Write Signal This Signal Will On When User Want Write Data On Memory(Cell)
2. Read Signal Will On When User Want Read From Memory(Cell).
Types Of Memory Cell
— If a symbol can be stored in a cell without continuous supply of energy, it known as non-volatile cell.
— If the symbol stored in a cell disappears when no energy is supplied, it is known as volatile cell.
— If a symbol is read from a cell its content should not be disturbed. Such a cell is known as non-destructive.
— If the symbol is erased, as a result of reading, is said to be destructive.
— The time taken to read a symbol from a cell is called read time and time taken to write a symbol is writetime.
— If in a memory cell, a symbol is permanently written and can only be read, then it is known as a read-only cell.
- This unit contains devices with the help of which we enter data into computer. This unit makes link between user and computer. The input device translate the information into the form understandable by computer.
- Accept or read data and instruction for computation.
- Data and instruction are depend upon the input device used.
- Computer memory accept input in binary form so Input Interface transfer that input signal to binary code.
Functions of Input Unit:
- It accepts instruction and data from outside world.
- It converts these instruction and data in computer acceptable form.
- It supplies the converted instruction and data to computer system for further processing.
Example of Input Unit:
- Grady Booch approach is known as object oriented design.
- The main aim is to establish a base for the implementation of object oriented systems.
- This methodology consists of identification of interfaces at various levels.
- The main concern of this method is the iterative process and creativity of the designer in order to develop OOD.
- It follows incremental and iterative life cycle.
- It combines analysis, designan implementation and provides a sound object oriented software engineering process for analysts, designers and developers.
- The Booch methodology can be broadly divided into two processes: macro process and micro process. It is a high-level process followed by development team throughout the life cycle.
1. Macro proces
- In the first phase, the requirements are established using context diagrams and prototypes. The outcomes of this phase are core requirements of the system.The analysis process involves requirement capturing and understanding.
- It involves what of the system. This phase consists of construction of use cases, identification and prioritization of risks.
The design phase focuses on the construction of architecture of the system and involves the following
- Identifying horizontal layers
- Mapping classes to subsystems
- Release planning
- Attaching risks identified in the analysis phase to releases.
- The evolutionary phase involves implementation of the system and each release adds to the functionality of the system.
- The maintenance phase consists of post-deployments activities.
2. Micro proces
It is a lower level process.
Following recursive steps are followed in OOD micro process:
- The first step involves finding class and objects at different levels of abstraction. The next identifies the semantics by finding the meaning of the classes and objects in terms of attributes and operations. It also involves determining the use of an object by another object.
- Identification of relationship involves the process of determining the interaction amongst the classes and objects.
- The relationships identified include inheritance, uses and instance of.
- The last involves specification of interface amongst classes and objects and their implementation. It identifies data type of attributes and signature of operations.
- Here no formal notations for constructing visual diagrams are given.
- Provide dedicated link between two devices.
- The entire capacity of channel is reserved for transmission between two device.
- Ex. TV remote control.
- More than two device share a single link.
- Capacity of the channel is either
- Spatially shared connection: devices can use the link simultaneously
- Timeshare connection: users must take turns.
- In prototyping model, a working prototype is constructed in order to determine and understand the customers need. The customer evaluates this prototype and then the final SRS document is prepared on the basis of refined requirements.
- The throwaway prototype which is developed undergoes design, coding and testing but not thoroughly and vigorously. During requirement analysis a quick and dirty prototype is constructed and given to the customer.
- The prototype is refined till the final requirements are reached.
- The final SRS is prepared which serves as input to the next phasr similar to the waterfall model.
- Stable requirements : Requirements are finalized by refining prototype again and again based on customer feedback.
- High quality system: The quality of the system will be high as developers get lot of experience while building the prototype.
- Low Cost : The cost of actual system will be reduced.
- Customer may expect quick delivery of the software.
- Time for development may exceed.