What is WannaCry ransomware attack explained in telugu | FACTS MOJO TELUGU

wanna cry ransomware attack గురించి తెలుసుకోవాలంటే  ఈ వీడియో చుడండి 

Read More

UNBELIVABLE FACTS ABOUT HUMAN BODAY | FACTS MOJO TELUGU

Read More

UNKNOWN FACTS ABOUT "THE GREAT PYRAMID" IN TELUGU | EGYPT | 2017

Read More

Top 5 Dangerous places in The world

This is my first #YOUTUBE Video please watch and #subcribe to my channel. like and watch and share my video guyzz i need your #support to do more #videos. thank you

Read More

The 8086 Microprocessor Architecture

The 8086 Microprocessor  Architecture

            The Intel 8086 is a 16-bit microprocessor intended to be used as the CPU in a microcomputer. The term “16-bit” means that its arithmetic logic unit, internal registers, and most of its instructions are designed to work 16-bit binary words. It has 16-bit data bus and 20-bit address bus.
Words will be stored in two consecutive memory locations. If the first byte of a word is at an even address, the 8086 can read the entire word in one operation. If the first byte of the word is at an odd address, the 8086 will read the first byte in one operation, and the second byte in another operation.
Following figure shows the internal block diagram of 8086 microprocessor. 

image source : SlideShare

   

The 8086 CPU is divided into two independent functional parts, the bus interface unit or BIU, and the execution unit or EU. 

The Bus Interface Unit

The BIU handles all data and addresses on the buses for the execution unit such as it sends out addresses, fetches instructions from memory, reads data from ports and memory as well as writes data to ports and memory. In BIU there are so many functional groups or parts these are as follows.

Instruction Queue

To increase the execution speed, BIU fetches as many as six instruction bytes ahead to time from memory. The pre fetched instruction bytes are held for the EU in a first in first out group of registers called a instruction queue. When the EU is ready for its next instruction, it simply reads the instruction from this instruction queue. This is much faster than sending out an address to the system memory and to send back the next instruction byte. Fetching the next instruction while the current instruction executes is called pipelining.

Segment Registers

The BIU contains four 16-bit segment registers. They are: the extra segment (ES) register, the code segment (CS) registers, the data segment (DS) registers, and the stack segment (SS) registers. These segment registers are used to hold the upper 16 bits of the starting address for each of the segments. The part of a segment starting address stored in a segment register is often called the segment base.
1. Code Segment (CS): The CS register is used for addressing a memory location in the Code Segment of the memory, where the executable program is stored.
2. Data Segment (DS): The DS contains most data used by program. Data are accessed in the
Data Segment by an offset address or the content of other register that holds the offset address.
3. Stack Segment (SS): SS defined a section of memory to store addresses and data while a subprogram executes.
4. Extra Segment (ES): ES is additional data segment that is used by some of the string to hold the extra destination data.

 Instruction Pointer (IP)

In the BIU, the next register, below the segment register is instruction pointer. The instruction pointer (IP) holds the 16-bit address of the next code byte within this code segment.

The Execution Unit

The execution unit (EU) tells the BIU where to fetch instructions or data from, decodes instructions, and executes instructions.
The functional parts of the execution unit are control circuitry or system, instruction decoder, and Arithmetic logic unit (ALU).
Control circuitry to perform various internal operations. A decoder in the EU translates instructions fetched from memory to generate different internal or external control signals that required performing the operation. The EU has a 16-bit ALU, which can perform arithmetic operations such as add, subtract etc. and logical operations such as AND, OR, XOR, increment, decrement etc. 

Flag Register

A 16-bit flag register is a flip-flop which indicates some condition produced by the execution of an instruction or controls certain operations of the EU. They are modified automatically by CPU after mathematical operations. It has 9 flags and they are divided into two categories:
1. Conditional Flags
2. Control Flags

Conditional Flags

Conditional flags represent result of last arithmetic or logical instructions.
· Carry Flag (CF): This flag will be set to one if the arithmetic operation produces the carry in MSB position. It is also used in multiple-precision arithmetic.
· Auxiliary Flag (AF): If an operation performed in ALU generates a carry/barrow from lower nibble (i.e. D0 – D3) to upper nibble (i.e. D4 – D7), the AF flag is set i.e. carry given by D3 bit to D4 is AF flag. This is not a general-purpose flag; it is used internally by the processor to perform Binary to BCD conversion.
· Parity Flag (PF): This flag is used to indicate the parity of result. If lower order 8-bits of the result contains even number of 1’s, the Parity Flag is set to one and for odd number of 1’s, the Parity Flag is reset i.e. zero.
· Zero Flag (ZF): It is set to one; if the result of arithmetic or logical operation is zero else it is reset.
· Sign Flag (SF): In sign magnitude format the sign of number is indicated by MSB bit. If the result of operation is negative, sign flag is set to one.
· Overflow Flag (OF): It occurs when signed numbers are added or subtracted. An OF indicates that the result has exceeded the capacity of machine.
Control Flags
Control flags are intentionally set or reset to control certain operations of the processor with specific instructions put in the program from the user. Control

flags are as follows:

1. Trap Flag (TP): It is used for single step control. It allows user to execute one instruction of a program at a time for debugging. When trap flag is set, program can be run in single step mode.
2. Interrupt Flag (IF): It is an interrupt enable/disable flag, i.e. used to allow/prohibit the interruption of a program. If it is set, the maskable interrupt is enabled and if it is reset, the interrupt is disabled.
3. Direction Flag (DF): It is used in string operation. If it is set, string bytes are accessed from higher memory address to lower memory address. When it is reset, the string bytes are accessed from lower memory address to higher memory address.

8086 Flag Register Format

General Purpose Registers

The EU has eight general purpose registers labeled AH, AL, BH, BL, CH, CL, DH, and DL. These registers can be used individually for temporary storage of 8-bit data. The AL register is also called the accumulator. Certain pairs of these general purpose registers can be used together to store 16-bit data. The valid register pairs are AH and AL, BH and BL, CH and CL and DH and DL. These register pairs is referred to the AX, BX, CX, and DX resp. 

1. AX Register: For 16-bit operations, AX is called the accumulator register that stores operands for arithmetic operations. 

2. BX Register: This register is mainly used as a base register. It holds the starting base location of a memory region within a data segment.

3. CX Register: It is defined as a counter. It is primarily used in loop instruction to store loop counter.

4. DX Register: DX register is used to contain I/O port address for I/O instruction. 

Stack Pointer Register

The stack pointer (SP) register contains the 16-bit offset from the start of the segment to the memory location where a word was most recently stored on the stack. The memory location where a word was most recently stored is called the top of stack.
Other Pointer and Index Registers
The EU also contains a 16-bit source index (SI) register, base pointer (BP) registers, and Destination Index (DI) registers. These three registers can be mainly used for temporary storage of 16-bit data just like a general purpose registers.

Read More

how to get rid of exam stress

              How to get rid of exam stress                     

Every student who aims to become a high-achiever will experience exam stress. It’s an unavoidable part of student life that can be a tough nut to crack. Remember, stress exists for a reason and you can choose to let it be your downfall or use it to drive you to improve your work.

    Outlined below are some unexpected ways that you can put those negative feelings to one side and concentrate on your learning goals. If you’re not stuck for inspiration at this moment (maybe you’re procrastinating by reading this?), you may be looking for this advice before your exams so take note!

1. Listen to Classical Music

Listening to music can create a positive and productive environment by elevating your mood and encouraging you to study more effectively and for longer. Classical music is recommended as the best type of music to boost your brain power but ambient music can work too. Check out the playlists on Spotify to easily find what works for you.

2. Take a Quick Walk

Many students feel as if they should spend their entire time before exams with their books open and their pen poised for action. However, research has proven that exercising such as taking a walk can boost your memory and brain power.

The image below shows the results of a study conducted by Dr. Chuck Hillman of the University of Illinois. It clearly demonstrates the effect exercise can have on your brain’s activity. Imagine how this could improve your exam performance!

3. Plan your Study Routine

This may not be a big surprise but what is shocking is the amount of students who discount the benefits of creating a personal study plan. With some initial effort, you can become more productive and motivated each day you approach your study by understanding your learning progress. If you’re using our learning platform, the GoConqr calendar tool will help you align your goals with your day-to-day study, get started here.

4. Play with Bubble Wrap & Puppies

Where do puppies come into exam stress? Lots of universities have installed ‘puppy rooms’ where students can come to relieve stress and anxiety. Pets have also been found to help you focus while studying but we wouldn’t recommend dropping into the library with your pet hamster! Popping bubble wrap is another stress reliever you can save for home study.

5. Try to Get Enough Sleep

For some people, this is something that’s always put on the long finger especially if you are trying to get the most out of college life. The benefits of a proper night’s sleep can never be underestimated. Most importantly, sleep helps your brain to assimilate new knowledge into your long-term memory so that you can recall it when it comes to test day. Anyone who has tried to concentrate with half a night’s sleep can also testify to improved focus with better sleep.

6. Use Mobile Apps

There are tons of mobile apps designed to improve your quality of life. Whether you want to get better organised, improve your mental arithmetic or work on your English language skills, there’s an app for that. We’ve even launched our own mobile apps for iOS and Android so you can make the most of your time no matter where you are. Downloading the app will give you access to over 2 million learning resources from around the world. Get the app for free here:

7. Give Your Mind Space

Meditation is one of the most effective ways to take a break and see your stress from a different perspective. Practicing meditation is another way to maintain focus while improving both mental and physical health to reduce pre-exam stress.

8. Eating Dark Chocolate

Believe it or not this is 100% true. Eating dark chocolate which is over 70% cocoa fights the stress hormone cortisol and has an overall relaxing effect on the body. Plus chocolate releases endorphins which act as a natural stress fighter.

9. Let it All Out

Sometimes you just need to talk to someone, other times you need to shout it from the rooftop or scream from the top of your lungs. Figure out what you’re feeling and then let it out. Speaking to a family member or friend can highlight the bigger picture for you and empower you to rise above the exam stress.

10. Break Free from Distractions

I bet you don’t even realise the number of times you check Facebook, Instagram or whatever your vice is? When you add it all up together, it amounts to a significant waste of time. It can be hard to detach from your life outside of studying but keeping the end goal and timeframe in mind will ease the process. We recommend the SelfControl website blocker.

Read More