Returns and procedures definitions in 8086, Computer Engineering

Assignment Help:

Q. Returns and Procedures definitions in 8086?

8086 microprocessor supports RET and CALL instructions for procedure call. CALL instruction not only branches to indicate address but also pushes return address onto the stack. Additionally it also initialized IP with address of the procedure. RET instructions basically pops the return address from stack. 8086 supports two types of procedure call. These are NEAR and FAR calls.

NEAR procedure call is also called as Intrasegment call as called procedure is in same segment from that call has been made. Hence only IP is stored as return address. IP can be stored on stack as:

912_Returns and Procedures definitions in 8086.png

Please note that the growth of stack is towards stack segment base. So stack becomes full on an offset 0000h. Also for push operation, we decrement SP by 2 as stack is a word stack (word size in 8086 = 16 bits) whereas memory is byte organised memory.

FAR procedure call which is also known as intersegment call is a call made to separate code segment. So the control will be transferred outside current segment. So both IP and CS need to be stored as return address. These values on stack after the calls looks as below:

597_Returns and Procedures definitions in 80861.png

When 8086 executes FAR call it first stores contents of code segment register followed by contents of IP on to the stack. A RET from NEAR procedure. Pops the 2 bytes in IP. RET from the FAR procedure pops 4 bytes from the stack.


Related Discussions:- Returns and procedures definitions in 8086

Illustrate about probability of collision, Illustrate about probability of ...

Illustrate about probability of collision? Probability of collision: There is a triangle and on this let’s assume that there are three ants one on each corner and are free t

How do you decide which integer type to use, It depends on our requirement....

It depends on our requirement. When we are needed an integer to be stored in 1 byte (means less than or equal to 255) we use short int, for 2 bytes we use int, for 8 bytes we use l

Explain about the term- reports, Explain about the term- Reports Repor...

Explain about the term- Reports Reports are produced as a result of questions like "how many times has a type of car broken down" or "which cities have the highest house price

Define virtual memory, Normal 0 false false false EN-IN...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Scope of expert system, The scope of the experts system is very limite...

The scope of the experts system is very limited. It cannot work outside the field it is being used. The users knowledge is required to adjust to new situation. To reduce

Elevation of the premature ventricular contraction, As spring approaches, y...

As spring approaches, your design firm has been tasked with designing a two-lane highway in rural Wyoming. The highway descends a hill, crosses a river, and must shift to a para

Meaning of every field in mips instruction, Q. Meaning of every field in MI...

Q. Meaning of every field in MIPS instruction? The meaning of every field in MIPS instruction is given below: op: operation code or opcode rs: First register source

Features of read-only memory, Q. Features of read-only memory? ROMs are...

Q. Features of read-only memory? ROMs are memories on which it's not possible to write data when they are on-line to computer. They can only be read. This is reason why it is k

Discuss about the electronic computer, Discuss about the Electronic compute...

Discuss about the Electronic computer The first general function programmable electronic computer was the Electronic Numerical Integrator and Computer (ENIAC), built by John V

What will be the output of JK flipflop for J = 0 and K=1, For JK flipflop J...

For JK flipflop J = 0, K=1, the output after clock pulse will be ? Ans. J=0 and K=1, such inputs will reset the flip-flop, after the clock pulse. Therefore whatever be the earlie

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd