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

What are user threads, What are User threads   User threads are support...

What are User threads   User threads are supported above the kernel and are executed by a thread library at the user level. Thread creation & scheduling are done in the user sp

Search methods and heuristics - artificial intelligence, Search Methods and...

Search Methods and Heuristics - Artificial intelligence: Here now we come to the question of how constraint solvers search for solutions -constraint preserving coursework of v

Classical approach - canonical genetic algorithm, Classical approach - Cano...

Classical approach - Canonical genetic algorithm: However returning to the classical approach, as there example, whether solving a particular problem involved finding a set of

Computer graphics, what do you mean by inter leasing.how it is display the ...

what do you mean by inter leasing.how it is display the frame having 525 scan lines

Procedure which divides a 32-bit number by a 16-bit number, Write a procedu...

Write a procedure which divides a 32-bit number by a 16-bit number. The procedure must be general which is it's defined in one module and can be called from another assembly module

Explain the term electronic data interchange (edi), Explain the term Electr...

Explain the term Electronic Data Interchange (EDI). Electronic Data Interchange (EDI) may be generally easy to understand as the replacement of paper-based purchase orders alon

Find minimum sampling rate of analog signal to be sampled, The analog signa...

The analog signal needs to be sampled at a minimum sampling rate of: (A) 2fs                                               (B) 1/(2fs) (C)  fs/2

State the approaches to organizing stored program control, Determine the ap...

Determine the approaches to organizing stored program control There are 2 approaches to organizing stored program control: 1.  Centralized: In this control, all control equi

Microprocessor and interfacing, Write an ALP to count positve and numbers f...

Write an ALP to count positve and numbers from array.

Stack operation and interrupts in microprocessor, Let us review the operati...

Let us review the operation of the stack within the 68HC11, the stack is a defined area of RAM which is last in first out register (LIFO) . Access to the stack is made via a stack

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