Timing diagram of 8086 microprocessor in minimum mode

In my previous post, I have explained  8086 microprocessor in minimum mode. This post explains the timing diagram of 8086 microprocessor in Minimum mode.

1. READ CYCLE TIMING DIAGRAM 

The read cycle begins in T1 with the assertion of ALE (Address latch enable ) and M/IO signal for memory or input-output process. During the negative going edge of the signal ,the valid address is latched on the local bus. The BHE or bus high enable and Ao signal addresses low , high or both bytes.

2. WRITE CYCLE TIMING DIAGRAM.

8086 microprocessor in minimum mode

Minimum mode in 8086 microprocessor :-
Microprocessor 8086 is operated in Minimum mode by strapping its MN/MX pin to logic 1.In this mode, all the control signals are given out by the microprocessor chip itself . There is a single microprocessor in the minimum mode system.
The figure below shows the microproceesor 8086 in minimum mode. The block digram shows various components in the systems like latches,transceivers,clock generator or i/o devices.
The latches that are used to separate the valid address from the multiplexed address are generally buffered utput D-type flip-flop,like 74lS373 . The latches are controlled by ALE. Transreceivers are bidirectional buffers and sometimes they are called data amplifiers.
DT/R indicates the direction of data. T means transfer in case of write and R means receiving data in case of write cycle.
20 address lines and 16 data lines is clearly shown in the figure below.

The working of the minimum mode in next post.

What is Discrete Memoryless Channel ?

Define :-  Discrete Memoryless Channel
A communication Channel may be defined as the path or medium through which the symbols flow to the receiver end. A  Discrete Memoryless Channel (DMC) is a statistical model with an input X and an output Y as shown in figure.

During each unit of time ,( the signaling interval ) , the channel accepts an input symbol from X, and in response an output symbol from Y. The channel is sais to be "discrete" when the alphabets of X and y are both finite.
Also,it is said to be "memoryless" and not on any of the previous inputs.

What is Entropy in Information Theory?

What is the concept of entropy?

A communication system transmit a long sequence of symbols from an information source that is , a communication system not deal with a single message but with all possible messages.
Thus we are more interested in the average information that a source produces rather than the information content of a single source.
Hence entropy is the average information per symbol .
Or   Average information per individual message.

It is a measure of uncertainty in a random variable.

Assumptions:
1 ) The source is stationary so that the probabilities remain constant with time.
2 ) The successive symbols are statistically independent  and come from the source at an average rate of being symbols per second.

Mathematical expression :

H(X) = E(I(x)) = -∑P(x)logP(x)  bits/symbol
Where H (X) is known as entropy of the source X.



Entropy for Binary source:

Information as a measure of uncertainty | Information in communication systems

In my previous post, I gave you Introduction about Information Theory. In this post I am going to tell about
Information , its unit, its uncertainty and mathematical relation.
First coming over to the amount of information contained in a message. Have you ever wondered about this?
Let us take an example : Suppose you are planning a tour a city located in such an area where rainfall very rare.
To know about the weather forecast you will call the weather bureau and may receive one of the following information:
1) It would be hot and sunny.
2) There would be rain.
3) There would be a cyclone.
It may be observed that the amount of information received is clearly different from the three messages. The first message, just for instance, contains very little information because the weather in a desert city in summer is expected to be hot and sunny for most of the time.
The second message i.e. rain contains more information because it is not an event that occurs often.
The third message i.e. cyclonic storms will contain the maximum amount of information as compared to the previous two. This is because the third event rarely happens in the city.
Thus,
There is an Inverse relationship between the probability of an event and information associated with it.

 I(x)=f[1 / p(x)]
Where I (x) represent the information and f means (it a function of ) while 1 / p (x) represents the inverse of probability.

Properties of Information content I (x) :
1)   I (x) = 0  For p (x) =1
2)   I(x) ≥ 0
3)   I (x_i)>1(x_j) if P(x_i)<P(x_j)
4)

NEXT POST : Entropy and its poperties.                                                                              

What is information Theory?

Information Theory is branch of probability theory which can be applied to the study of the communication systems.
It is a broad mathematical discipline and it has made fundamental contributions not only to communications but also computer science,statiscal physics and probability and statistics.

This concept of Information Theory was invented by communication scintists while they were studying the statistical structure of electronic communication equipments.
A basic Communication system consists of three components:

1 ) Transmitter
2 ) Medium or channel
3 ) Receiver

When the communique or message is measureable Like current or voltage then the study of communication system is very easy but When the communique is Information ,then the study becomes quite difficult.
So, Information theory studies all these kind of Questions regarding the information ,whats its unit and how it is  transferred.

A communication system is Non-deterministic i.e. thst means it has statiscal nature.Thus a communication system has uncertainity or in other words a communication system possesses unpredictability.
The amount of information(it is a parameter) associated with an event can not be determined.

NEXT POST : Information as a measure of uncertaininty.

Array processors -SIMD Array processor

In my previous post i discussed What are array processor and its first type that is the attached array processor that is used fr carrying out scientific numerical applications by attaching an auxillary processor along with General host computer. READ full post here.
IN this tutorial i am going to tell about SIMD ARRAY PROCESSOR :
SIMD stand for Single instruction multiple data Instruction.
It consists of multiple processing units or elements that are operating in parallel and are synchronized to perform the same task  or operation under the control of a common control unit. HENCE the name is single instruction multipla data.
  A general BLOCK DIAGRAM IS shown below.

 

Thus it contains a set of processing elements (PE'S ) ,each having a local memory M. Each processor element includes an ALU. a floating arithmetic unit,and working registers.The master control unit controls the operation in the procssor elements.

AN INDIVIDUAL PE(PROCESSING ELEMENT)

Each PE has its own local memory. MAIN MEMORY IS used for the storage of program while master control unit  controls the operations in the processor elements.it decodes the instructions and decde how a particular  instruction will be executed.
THE SCALER instructions is executed by the control unit itself while the vector instructions are send to all the PE'S  simulataneously.


BEST KNOWN SIMD ARRAY PROCESSOR IS THE ILLIAC IV COMPUTER..

What is ARRAY PROCESSOR ? Its types

ARRAY processor is  a processor that performs computations on a large array of data.
It is also called vector processor.(It execute one instruction at a time but on array of data.)
Array processor is of two types:-

1) ATTACHED ARRAY PROCESSOR
2) SIMD ARRAY PROCESSOR

Coming over attached array processor - In this an auxillary processor is attached to a general purpose computer.It enhances the performance of the host computer in specific numerical computation tasks.
* It provides vector processing for complex scientific applications.
* This attachment is done by parallel processing i.e. it contains  one or more pipelined floating point adders and multipliers.
Can be programmed by user.



GENERAL PURPOSE
COMPUTERS                <------------->  I/O INTERFACE  <-------------->ATTACHED ARRAY PRO.
          |                                                                                                                      |
          |                                                                                                                      |
          |                                                                                                                      |
  MAIN MEMORY        <------------------------------------------------------>        LOCAL MEMORY

The attached array processor is attached to host computer by a input-output interface or controller and The data for the attached processor are transferred from main memory to a local memory through a high speed bus.
NEXT POST. SIMD ARRAY PROCESSOR

continue reading  SIMD PROCESSOR....

INTRODUCTION TO THE WORLD OF MICROCONTROLLERS | 8051 FAMILY

In my earlier posts I've given introduction to tha embedded systems,then moved on to the what are  microcontrollers and  diffrence between microcontrollers and microprocessors 
In this post i'll be introducing you to the world of microcontrollers and the most common 8051 family.
There are various 8 bit and even more (16 or 32 bit)  microcontrollers available,the most common is 8-bit microcontrollers and the firms manufacturing them are :
Motorola's 6811  , Intel 8051 , Microchip's pic.

Before CHOOSING a microcontroller for an embedded system,the need must be noticed and accordingly microcontrollers  configuration is choosed :

NOW coming on 8051 microcontrollers. They are the most common among microcontrollers family. A large number of firms manufactures it.
some among them are :
Intel,Atmel,Philips,amd,Matra,dallas semicontuductors,Siemens


Intel introduced its 8051 microcontrollers known by name MCS 51 in 1981

It is a8 bit microcontroller that means 8 bits of data can be processed at a time.

CONFIGURATION/FEATURES OF 8051:
1) 128 BYTES OF RAM
2) 4 KB ROM
3) TWO TIMERS
4) 4 I/O PORTS
5) 6 INTEREPPT SOURCE
6) ONE SERIAL PORT

                                       BLOCK DIAGRAM OF 8051 MICROCONTROLLERS

                                                                       8051  family

continue reading other family members

DIFFERENCE BETWEEN MICROCONTROLLERS AND MICROPROCESSORS

In this post i'll make your query clear regading the difference between microprocessors and microcontrollers.

First of all microcontollers: As the name suggests microcontollers are derived from two words micro  + controllers. That is they are small is size and used for controlling purposes of an embedded system.

On the other hand microprocessor reminds us of the PC's processors such as intels's 8085, x86(8086),pentium 3,4, motorola 680x0 and nows a days we are having super fast and stable microprocessors like i3.i5,i7 and technology will be more advanced in future.


THE BASIC DIFFERENCE BETWEEN A MICROPROCESSORS AND MICROCONTROLLERS IS THAT IN MICROPROCESSORS THERE ARE NO INTEGRATED RAM, ROM ,I/O PORTS,TIMERS, AND OTHER PERIPHERALS..


THESE ALL NEED TO BE CONNECTED EXTERNALLY TO MAKE THE FUNCTIONAL

WHILE IN MICROCONTROLLERS ALL THESE "RAM,ROM,I/O PORTS,TIMERS ARE INTEGRATED"


In other words, the processor, the RAM, ROM, I/O ports and the timer are all embedded together on one chip.

TAKE A LOOK BELOW (Click to see the enlarged view)

thus to summerize :)


General-purpose microprocessors
a) Must add RAM, ROM, I/O ports, and
timers externally to make them functional

b) Versatility on the amount of RAM, ROM, and I/O ports

c)Make the system bulkier and much more
expensive.

Microcontroller

The fixed amount of on-chip ROM, RAM,
and number of I/O ports makes them ideal
for many applications.and generally are less expansive but depends upon application






8051 microcontrollers :

EMBEDDED SYSTEM MICROCONTROLLERS BASICS | 8051 microcontollers

In my previous post, I've given you   an introduction about embedded system and its applications
In this post I'll be introducing you to the world of microcontrollers and the most common 8051 family microcontrollers. As I have told you that embedded system is a combination of software and hardwares. Softwares deals with the task and flexibilites a system does and hardware part deals with the microcontrollers.

MICROCONTROLLERS IS OFTEN ASSOCIATED  AS MICROPROCCSESORS BUT THERE ARE SOME DIFFERENCES BETWEEN THEM.

In general purpose microprocessors there is no RAM, ROM, I/O PORTS, TIMERS and other peripherals
While  microcontrollers has
*A CPU (Microproceesor)
*RAM
*ROM
*I/O PORTS
*TIMER
*ADC (A TO D CONV.)   etc.

CLICK N IMAGE TO SEE THE ENLARGED VIEW
The image describes the microcontllrers and microprocessors. In general purpose microprocessors external ram,rom,i/o prts,timers and other peripherls need to be added to make them functional.

READ ABOUT 8051 FAMILY MICROCONTROLLERS

INTRODUCTION TO EMBEDDED SYSTEMS AND MICROCONTROLLERS

We are living in the embedded world. We are surrounded by so many embedded products like electronics gadgets namely mobile phones, card readers, TV, radio, washing machines, ovens etc.

What actually are embedded systems :-
THESE ARE BASICALLY A COMBINATION OF SOFTWARE AND HARDWARE AND ARE DESIGNED TO PERFORM A PARTICULAR TAK OR FUNCTION. So we can say it is a computer system that means it do computing.

As I have told you that embedded systems is a combination of software and hardware. The software deals  with the function or task that a particular system performs and  hardware refers to the controllers I.e. embedded system is controlled by hardware known as a microcontroller.

So an embedded system forms an important part of our life and its scope is wide. From mp3 player , wrist watches to air traffic control and  nuclear power plants , everything is an embedded system i.e. performs a particular task.

 A Personal computer is not an embedded system :
Yes that's true  a computer or a laptop is not an embedded system because a computer can carry out many tasks such as calculations, processing, internet, sending mails, playing games, music, image processing, etc. Whereas an embedded system has its property that it is designed to do a particular task.

So I hope you have got an introduction to embedded systems ;
Continue reading    MICROCONTROLLERS AND 8051 FAMILY

THIS BLOG IS UNDER CONSTRUCTION BUT SOON IT WILL ROCK

BLOG UNDER CONSTUCTION............SOON IT WILL ROCK

pn junction diode and its v/i characteristics

diode is one of the most common element of electronics.it is used widely here is the post explaining v/i characteristics of diode

The operation of diodes (as with other semiconductor devices) is often described by a special graph called a "characteristic curve". These graphs show the relationship between the currents and voltages associated with the different terminals of the device. An understanding of these graphs helps in understanding how the device operates.

For diodes the characteristic curve is called an I/V curve because it shows the relationship between the voltage applied between the anode and cathode, and the resulting current flowing through the diode. A typical I/V characteristic is shown in figure:

The axes of the graph show both positive and negative values and so intersect at the centre. The intersection has a value of zero for both current (the Y axis) and voltage (the X axis). The axes +I and +V (top right) show the current rising steeply after an initial zero current area. This is the forward conduction of the diode when the anode is positive and cathode negative. Initially no current flows until the applied voltage is at about the forward junction potential, after which current rises steeply showing that the forward resistance (I/V) of the diode is very low; a small increase in voltage giving a large increase in current.

The -V and -I axes show the reverse biased condition (bottom left). Here we see that although the voltage increases hardly any current flows. This small current is called the leakage current of the diode and is typically only a few micro-amps with germanium diodes and even less in silicon. If a high enough reverse voltage is applied however there is a point (called the reverse breakdown voltage) where the insulation of the depletion layer breaks down and a very high current suddenly flows. In most diodes this breakdown is permanent and a diode subjected to this high reverse voltage will be destroyed. In Zener diodes however, this point is used to give the diode its special ability to stabilise the applied voltage: If the voltage increases at this point heavy current flows and reduces the voltage. The breakdown in a Zener diode is not destructive due to its special construction.

various electronics components...

 

     TRY TO  IDENTIFY COMPONENTS........ 

       HOW MUCH YOU KNOW???

What is ELECTRONICS? INTRODUCTION..

Every individual must be aware with the term electronics. On hearing the word "electronics" one must come across television, lcds, i pads, mobiles, washing machines and related things THAT ARE CONSUMER ELECTRONICS     .... But what actually ELECTRONICS is
ACCORDING TO WIKIPEDIA :-
Electronics is the branch of science and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits.
MOST OF THE COMMON PERSONS MIGHT NOT BE AWARE OF SUCH COMPONENTS LIKE DIODES, ICS, TRANSISTORS ETC BUT THESE ARE THE BASIC COMPONENT OF ALL OF THE GADGETS AND ELECTRONICS THINGS LIKE MOBILEs
WELL HINDI VERSION OF WIKIS SAYS  :- 
विज्ञान के अन्तर्गत इलेक्ट्रॉनिक्स या इलेक्ट्रॉनिकी वह क्षेत्र है जो विभिन्न प्रकार के माध्यमों ( निर्वात, गैस, धातु, अर्धचालक, नैनो-संरचना आदि) से होकर आवेश ( मुख्यतः इलेक्ट्रॉन) के प्रवाह एवं उसके प्रभाव का अध्ययन करता है। THOSE WHO HAVE NOT UNDERSTOOD I IT SIMPLY SAYS THAT ELECTRONICS IS THE BRANCH OF SCIENCE THAT DEALS WITH THE FLOW OF ELECTRONS AND RELATED BEHAVIOUR

FIRST POST ON http://abcofelectronics.blogspot.com/

I have been blogging for around a month. Its quite interesting to write on blogs. I have two more blogs @
http://himanshudureja.yolasite.com/blog.php 
                       AND
http://himanshudureja.blogspot.com/   
CHECK 'EM OUT.
As i am doing btech in electronics and communication brach and love blogging. so i have made another blog dedicated to electronics basics and other things just related to electronics. Hopes i come out with best stuff related to my blog.