8086 MICROPROCESSOR
Before knowing the 8086 microprocessor first we want to know what is microprocessor... introduction to microprocessor...
Microprocessor use every where in the world . Where there is a program then there is a microprocessor in it .they use in mobile phones, laptops(i3,i5,i7,i7,i9).
Example:
When you observe the traffic lights There is a microprocessor to count numbers and glow lights(red, green yellow).there are lot many more examples .
Which use the microprocessors.
8086 microprocessor.
It is intel complete commercial and remarkable processor.
8086 is 16 bit processor that means it can transfer 16 bit data .
Because of pipelining 8086 microprocessor divided into two parts .
1.BIU(bus interface unit)
Top you can see 8086 microprocessor which separated by doted lines the upper part is called bus interface unit .in this unit microprocessor first it fetch
The instructions side by side in advance. every microprocessors have 4 basic operations fetching, decoding, executed, store the results in memory
FIRST WE DISCUSS ABOUT THE MEMORY INTERFACE
Every thing has some address right. if you want to access a song or a video you must store in a file that your convince it is virtual address ..but computer converts it in binary form and allot some locations (physical address) every file in memory. If you want to access specific file then you need address of that specific file ..these memory segments as divided into 4 types code(cs),stack(cs),data(ds),extra(es)..there are two types of address segment address and off-set address
Example:.
Consider a book of 100 pages so if you want a 56th page ..it is in 3rd chapter so here the segment address tell us where we begin and offset address tell us exact location
Segment Register's.
Segment address is different and segment register's are different. this segment register's tell where the segment address start from. IP stands for instruction point they always point to next offset address
To calculate the physical address we have one formula physical address=segment address*10+offset address
Segment address +offset address=physical address.
This entire process happen in memory itself .when it calculated physical address then in that address fetch through the data bus
There are 3 types of buses
Address bus=we give address.
Data bus= instructions will fetch inside the processor
Control bus =tell the processor to read or write.
After fetching from the memory through data bus it transfer to queue....
QUEUE.
This consists of 6 bytes this work on first in first out the EU( execution unit) excite every two bytes of instructions. when these two bytes are empty then data bus fetch two bytes and fill in queue ..this fetching process continues all the time.
The longest instruction is about 6 bytes in 8086 microprocessor
First part is completed let's summaries .
1.calculate physical address
2.transfor data with memory and fetch instructions using data bus .
3 manage the queue this done by BIU .
4.size of the queue is 6 bytes .
5 queue is refill when two bytes are empty.
6 segment register's contain starting address.
7 segments are present in memory...
Part 2
EXICUITION UNIT (EU)
Excite unit used to exciting the instructions ..
The instructions in queue first two bytes enter control unit
Every code we write in assembly language but while exciting .control system converts assembly language to machine language ..this process is called decoding control system responsible for what operation as to be done by arithmetic operator....
ARITHMETIC OPERATOR.
This is used to perform arithmetic operations such as addition, substation decision so on
This is special kind of block which is used for programming and each block have 8 bits combination of two blocks have 16 bits
OPERANDS AND FLAGS.
Operands it is a temporary storage register use by the processor for storing temporary values .
Example: consider a swapping of two numbers Bx=4,cx=5 if we want to interchange it then we must need a temporary registration
FLAGS
flag register have various flags each flag give some status about how the current result..
Example :
Sign flag: which tell result +ve or -ve
Zero flag: which tell the result zero or not..
Carry flag which tell result is carry one or not .
There are many flags.
I hope you like this article if you have any questions comment below....thank you