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

Advantages and disadvantages of e-commerce, E-commerce is one of the most s...

E-commerce is one of the most significant aspects of the internet. Having emerged recently and growing at a steady state, it becomes essential to look at the advantages and disadva

Define the meaning of document and finger print, a. Define the meaning of "...

a. Define the meaning of "Document & Finger print" and "Message & Message Digest". What's the difference among the 2 pairs? b. Describe Davies Meyer scheme with diagram. c. W

What are the ways to create a new form, What are the ways to create a new f...

What are the ways to create a new form? You can make a new form in any of the following three ways: Using AutoForm: You can make a form based on a single table or query qui

Show error detection mechanism, Q. Show Error detection mechanism? Erro...

Q. Show Error detection mechanism? Error detection mechanism can be described as below: Figure: Error detection and correction

What types of data entry services do you perform, What types of data entry ...

What types of data entry services do you perform? Our business is to understand what data you require entered and in what particular format. After an initial analysis is perfor

Determining the error models that affect program execution, In critical com...

In critical computer applications the correctness of a delivered output and the continuity of the required service beside the speed of the used CPU are the most important measures

What are the advantages of carrying out simulations, What are the Advantage...

What are the Advantages of carrying out simulations -  saves cost (instead of doing the real thing) -  Safer (scenarios tried out on the simulation first before used in real

What is uml architecture, Takes care structural and behavioural aspect of a...

Takes care structural and behavioural aspect of a software system. Contains software usage, functionality, performance, economic, reuse, and technology constraints.

Desirable choice for the partitioning element in quick sort, A desirable ch...

A desirable choice for the partitioning element in quick sort is First element of the list.

Describe the term- systems analysis, Describe the term- Systems Analysis ...

Describe the term- Systems Analysis A systems analysis team is every so often brought in to improve on an existing system. Often this involves moving from a paper-based filing

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