EC6504-MICROPROCESSOR AND MICROCONTROLLER

1. Define microprocessor?

A microprocessor is a multipurpose, programmable, clock-driven, register –based electronic device that reads binary instructions from a storage device called memory . Accepts binary data as input and processes data according to instructions, and provides result as output.

2.  Explain  the  function  of ALE	in  the  8085	architecture?	(or)  How address	and  data lines	are
demultiplexed?
The ALE  signal  goes  high  at the	beginning of	each machine	cycle indicating the	availability of	the

address on the address bus, and the signal is used to latch the low-order address bus(A0-A7) by demultiplexing the address/data bus(AD0-AD7),which are multiplexed.

3.        What is the function of HOLD and HLDA?

HOLD- It indicates when another device is requesting the use of address and data bus(like DMA controller). HLDA(Hold Acknowledge)- It indicates that HOLD request has been received. After the removal of HOLD request the HLDA goes low.

4.  What is the purpose of READY and TRAP pins in 8085 Microprocessor?

READY- It is used to interface slow speed peripherals with microprocessor. TRAP- Vectored and non-maskable hardware interrupt.

5.        List the operations performed by IO/M in 8085.

Memory Read, Memory Write ,I/O Read, I/O Write are the operations performed by IO/M in 8085.

6.        Differentiate between Memory mapped I/O and I/O mapped I/O.

S.NO	Memory mapped I/O	I/O mapped I/O
1.	It is treated as memory location	It is not treated as memory location
2.	No special instructions are needed to access	It  requires  special  instructions  like IN,
	the I/O devices	OUT to access I/O devices
3.	Microprocessor   can   access   1  MByte	Microprocessor  can  access  64  KByte
	memory locations or I/O ports	memory locations or I/O ports
4.	It requires 20 address lines	It requires 16 address lines
5.	MEMR,  MEMW  signals  can  be  used to	IOR , IOW signals are used
	access I/O devices
6.	It is suitable for small system	It is suitable for large system

MULTIMEDIA

1. What are the sequences of steps for each HTTP request from a client to the server?

1. Making the connection

2. Making a request

3. The response

4. Closing the connection

2. Write a note on Internet Information Server (IIS)?

Microsoft’s Web server that runs on Windows NT platforms, In fact, IIS comes

Bundled with Windows NT 4.0. Because IIS is tightly integrated with the operating system, it is relatively easy to administer. However, currently IIS is available only for the Windows NT platform, whereas Netscape’s Web servers run on all major platforms, including Windows NT platform, OS/2 and UNIX.

3. Explain about HTTP Connection?

It is a communication channel between web browser and web server. It begins on the

Client side with the browser sending a request to the web server for a document.

Request Header Fields are

1. From

2. Reference

3. If_modified_since

4. Pragma

5. User Agent

4. What is meant by Stateless Connection?

When a web server receives a HTTP request from a web browser it evaluates the

request and returns the requested document, if it exists, and then breaks the HTTP connection. This document is preceded by the response header, which has details about how to display the document that will be sent by the server. Each time a request is made to the server, it is as if there was no prior connection and each request can yield only a single document. This is known as Stateless Connection.

DHTML(DYNAMIC HTML)

1. What are the necessities of using HTML forms?

1. Gathering user information

2. Conducting Surveys

3. Interactive services

2. Define HTML.

It is a simple page description language, which enables document creation for the web

3) Explain about <TABLE> &<FRAME> tags in Detail?

Code for Basic HTML Table

<TABLE>

<TR>----------</TR> <! ---Row1--->

<TR>----------</TR> <! ---Row2-->

-------------------------

<TR>----------</TR> <! ---Row n-->

</TABLE>

Creating a Table cell.

i) Header cell

ii) Data cell

Table Alignment

i) Aligning the Entire Table

ii)Alignment within a row.

ii) Alignment within a cell.

Spanning Multiple Rows & Columns

<FRAMES>

Creating the <FRAMESET> tag

Creating the <FRAME> tag

Eg:<FRAMESET Rows=”10%,80%,10%”>

<FRAME name=”top” src=”a.html”>

<FRAME name=”mid”src=”b.html”>

<FRAME name=”bot” src=”c.html”>

</FRAMESET> (16)

4. Write a note on proxy server?.

A proxy server is a host that makes Internet request on behalf of other machines on the

network, Proxy servers are often used to cache frequently requested files or to monitor Internet use within a Corporation.

5. What does DHTML refer?

DHTML refers to collection of technologies, which makes HTML documents more dynamic and interactive.

CS2302-COMPUTERNETWORKS

17. Define Aggregation points?

            It collects and processes the data they receive from neighboring nodes, and then transmit the processed data. By processing the data incrementally, instead of forwarding all the raw data to the base station, the amount of traffic in the network is reduced.

18. Define Beacons?

            Beacon to determine their own absolute locations based on GPS or manual configuration. The majority of nodes can then derive their absolute location by combining an estimate of their position relative to the beacons with the absolute location information provided by the beacons.

19. What is the use of Switch?

            It is used to forward the packets between shared media LANs such as Ethernet. Such switches are sometimes known by the obvious name of LAN switches.

20. Explain Bridge?

            It is a collection of LANs connected by one or more bridges is usually said to form an extended LAN. In their simplest variants, bridges simply accept LAN frames on their inputs and forward them out on all other outputs.

21. What is Spanning tree?

            It is for the bridges to select the ports over which they will forward frames.

22. What are the three pieces of information in the configuration messages?

1.      The ID for the bridge that is sending the message.

2.      The ID for what the sending bridge believes to the root bridge.

3.      The distance, measured in hops, from the sending bridge to the root bridge.

23. What is broadcast?

            Broadcast is simple – each bridge forwards a frame with a destination broadcast address out on each active (selected) port other than the one on which the frame was received.

CS2302-COMPUTERNETWORKS - Unit 2

1. What are the functions of MAC?

            MAC sub layer resolves the contention for the shared media. It contains synchronization, flag, flow and error control specifications necessary to move information from one place to another, as well as the physical address of the next station to receive and route a packet.

2. What are the functions of LLC?

The IEEE project 802 models take the structure of an HDLC frame and divides it into 2 sets of functions. One set contains the end user portion of the HDLC frame – the logical address, control information, and data. These functions are handled by the IEEE 802.2 logical link control (LLC) protocol. 

3. What is Ethernet?

            Ethernet is a multiple-access network, meaning that a set of nodes send and receive frames over a shared link.

4. Define the term carrier sense in CSMA/CD?

            All the nodes can distinguish between idle and a busy-link and “collision detect” means that a node listens as it transmits and can therefore detect when a frame it is transmitting has interfered (collided) with a frame transmitted by another node.

5. Define Repeater?

            A repeater is a device that forwards digital signals, much like an amplifier forwards analog signals. However, no more than four repeaters may be positioned between any pairs of hosts, meaning that an Ethernet has a total reach of only 2,500m.

6. Define collision detection?

            In Ethernet, all these hosts are competing for access to the same link, and as a consequence, they are said to be in the same collision detection.

7. Why Ethernet is said to be a I-persistent protocol?

            An adaptor with a frame to send transmits with probability ‘1 ‘whenever a busy line goes idle.

8. What is exponential back off?

            Once an adaptor has detected a collision and stopped its transmission, it waits a certain amount of time and tries again. Each time it tries to transmit but fails, the adaptor doubles the amount of time it waits before trying again. This strategy of doubling the delay interval between each transmission attempt is a general technique known as exponential back off.

CS2302-COMPUTERNETWORKS

29. What is the purpose of hamming code?

A hamming code can be designed to correct burst errors of certain lengths. So the simple strategy used by the hamming code to correct single bit errors must be redesigned to be applicable for multiple bit correction.

30. What is redundancy?

It is the error detecting mechanism, which means a shorter group of bits or extra bits may be appended at the destination of each unit.

31. Define flow control?

Flow control refers to a set of procedures used to restrict the amount of data. The sender can send before waiting for acknowledgment.

32. Mention the categories of flow control?

There are 2 methods have been developed to control flow of data across communication links. a) Stop and wait- send one from at a time. b) Sliding window- send several frames at a time.

33. What is a buffer?

Each receiving device has a block of memory called a buffer, reserved for storing incoming data until they are processed.

34.What is the difference between a passive and an active hub?

An active hub contains a repeater that regenerates the received bit patterns before sending them out. A passive hub provides a simple physical connection between the attached devices.

35.  For n devices in a network, what is the number of cable links required for a

mesh and ring topology?

·         Mesh topology – n (n-1)/2

·         Ring topology – n

CS2302 Computer Network

15.  How does NRZ-L differ from NRZ-I?

In the NRZ-L sequence, positive and negative voltages have specific meanings: positive for 0 and negative for 1. in the NRZ-I sequence, the voltages are meaningless.

Instead, the receiver looks for changes from one level to another as its basis for recognition of 1s.

16. What are the responsibilities of data link layer?

Specific responsibilities of data link layer include the following. a) Framing b) Physical addressing c) Flow control d) Error control e) Access control.

17. What are the ways to address the framing problem?

·         Byte-Oriented Protocols(PPP)

·         Bit-Oriented Protocols(HDLC)

·         Clock-Based Framing(SONET)

18. Distinguish between peer-to-peer relationship and a primary-secondary relationship. peer -to- peer relationship?

            All the devices share the link equally.

Primary-secondary relationship: One device controls traffic and the others must transmit through it.

19. Mention the types of errors and define the terms?

            There are 2 types of errors

·         Single-bit error.

·         Burst-bit error.

Single bit error: The term single bit error means that only one bit of a given data unit (such as byte character/data unit or packet) is changed from 1 to 0 or from 0 to 1.

Burst error:  Means that 2 or more bits in the data unit have changed from 1 to 0 from 0 to 1.

20.  List out the available detection methods.

             There are 4 types of redundancy checks are used in data communication.

·         Vertical redundancy checks (VRC).

·         Longitudinal redundancy checks (LRC).

·         Cyclic redundancy checks (CRC).

·         Checksum.

21. Write short notes on VRC.        

The most common and least expensive mechanism for error detection is the vertical redundancy check (VRC) often called a parity check. In this technique a redundant bit called a parity bit, is appended to every data unit so, that the total number of 0’s in the unit (including the parity bit) becomes even.

CS2302-COMPUTERNETWORKS - Unit 1

1. What are the three criteria necessary for an effective and efficient network?

The most important criteria are performance, reliability and security.

Performance of the network depends on number of users, type of transmission medium, and the capabilities of the connected h/w and the efficiency of the s/w.

Reliability is measured by frequency of failure, the time it takes a link to recover from the failure and the network’s robustness in a catastrophe.

Security issues include protecting data from unauthorized access and viruses.

2. Group the OSI layers by function?

The seven layers of the OSI model belonging to three subgroups.

Physical, data link and network layers are the network support layers; they deal with the physical aspects of moving data from one device to another.

Session, presentation and application layers are the user support layers; they allow interoperability among unrelated software systems.

The transport layer ensures end-to-end reliable data transmission.

3. What are header and trailers and how do they get added and removed?

Each layer in the sending machine adds its own information to the message it receives from the layer just above it and passes the whole package to the layer just below it. This information is added in the form of headers or trailers. Headers are added to the message at the layers 6,5,4,3, and 2. A trailer is added at layer2. At the receiving machine, the headers or trailers attached to the data unit at the corresponding sending layers are removed, and actions appropriate to that layer are taken.

4. What are the features provided by layering?

            Two nice features:

·         It decomposes the problem of building a network into more manageable components.

·         It provides a more modular design.

5. Why are protocols needed?

In networks, communication occurs between the entities in different systems. Two entities cannot just send bit streams to each other and expect to be understood. For communication, the entities must agree on a protocol. A protocol is a set of rules that govern data communication.

6.  What are the two interfaces provided by protocols?

·         Service interface

·         Peer interface

Service interface- defines the operations that local objects can perform on the protocol.

Peer interface- defines the form and meaning of messages exchanged between protocol peers to implement the communication service.

7. Mention the different physical media?

·         Twisted pair(the wire that your phone connects to)

·         Coaxial cable(the wire that your TV connects  to)

·         Optical fiber(the medium most commonly used for high-bandwidth, long-distance links)

·         Space(the stuff that radio waves, microwaves and infra red beams propagate through)

COMPUTER NETWORKS

1. What are the three criteria necessary for an effective and efficient network?

The most important criteria are performance, reliability and security.

Performance of the network depends on number of users, type of transmission medium, and the capabilities of the connected h/w and the efficiency of the s/w.

Reliability is measured by frequency of failure, the time it takes a link to recover from the failure and the network’s robustness in a catastrophe.

Security issues include protecting data from unauthorized access and viruses.

2. Group the OSI layers by function?

The seven layers of the OSI model belonging to three subgroups.

Physical, data link and network layers are the network support layers; they deal with the physical aspects of moving data from one device to another.

Session, presentation and application layers are the user support layers; they allow interoperability among unrelated software systems.

The transport layer ensures end-to-end reliable data transmission.

3. What are header and trailers and how do they get added and removed?

Each layer in the sending machine adds its own information to the message it receives from the layer just above it and passes the whole package to the layer just below it. This information is added in the form of headers or trailers. Headers are added to the message at the layers 6,5,4,3, and 2. A trailer is added at layer2. At the receiving machine, the headers or trailers attached to the data unit at the corresponding sending layers are removed, and actions appropriate to that layer are taken.

4. What are the features provided by layering?

            Two nice features:

·         It decomposes the problem of building a network into more manageable components.

·         It provides a more modular design.

5. Why are protocols needed?

In networks, communication occurs between the entities in different systems. Two entities cannot just send bit streams to each other and expect to be understood. For communication, the entities must agree on a protocol. A protocol is a set of rules that govern data communication.

UNIT I SOFTWARE PRODUCT AND PROCESS

1. List the process maturity levels in SEIs CMM.

            Level 1: Initial - Few processes are defined and individual efforts are taken.

Level 2: Repeatable – To track cost schedule and functionality basic project   management processes are established.

Level 3:  Defined – The process is standardized, documented and followed.

Level 4: Managed – Both the software process and product are quantitatively understood and controlled using detailed measures.

Level 5: Optimizing – Establish mechanisms to plan and implement change. 

2. What is an effector  process?

The effector process is a process that verifies itself. The effector  process exists in certain criteria.

3. Define the computer based system.

The computer based system can be defined as “a set or an arrangement of elements that are organized to accomplish some predefined goal by processing   information”.

4. What does Verification represent?

Verification represents the set of activities that are carried out to confirm that the software correctly implements the specific functionality.

5.  What does Validation represent?

Validation represents the set of activities that ensure that the software that               has been built is satisfying the customer requirements.

6. What are the steps followed in testing?

1) Unit testing - The individual components are tested in this type of testing.

2) Module testing – Related collection of independent components are tested.

            3) Sub-system testing –Various modules are integrated into a subsystem and the whole subsystem is tested.

            4) System testing – The whole system is tested in this system.

            5) Acceptance testing – This type of testing involves testing of the system with customer data.

CS 2301 - SOFTWARE ENGINEERING -Unit 1

1. What is software engineering?

                    Software engineering is a discipline in which theories, methods and tools  are applied to develop professional software.

2. What is Software?

                           Software is nothing but a collection of computer programs that are related documents that are indented to provide desired features, functionalities and better performance. 

3. What are the characteristics of the software?

               * Software is engineered, not manufactured.

                           * Software does not wear out.

               * Most software is custom built rather than being assembled from components.

 4. What are the various categories of software?

                          * System software

              * Application software

                          * Engineering/Scientific software

              * Embedded software

                          

  5. What are the challenges in software?

               * Copying with legacy systems.

                           * Heterogeneity challenge

               * Delivery times challenge.

  

   6. Define software process.

                            Software process is defined as the structured set of activities that are required to develop the software system.