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

Kirchoff''s voltage law , Kirc hoff's Voltage Law   The sum ...

Kirc hoff's Voltage Law   The sum of all the voltage drops around a closed circuit loop will add to zero  V1+(-V2)+(-V3)+(-V4)= 0

Utilization summary, Utilization Summary The Utilization Summary shows ...

Utilization Summary The Utilization Summary shows the status of each processor i.e. how much time (in the form of percentage) have been spent by every processor in busy mode, o

Cache simulater, Requirements You are required to program (in a high l...

Requirements You are required to program (in a high level language such as C, C++, Java) and implement a cache simulator which will have the following inputs and outputs:-

Handshake packets - computer architecture, Handshake packets: Handshak...

Handshake packets: Handshake packets consist of nothing but a PID byte, and are usually sent in response to data packets. The 3 basic types are, NAK, indicating that the data

Design combinational-sequential electronic logic gate, Combinational/Sequen...

Combinational/Sequential Logic design with Integrated Circuits (Dual in line package) Car wash concept with the following steps in a Combinational Logic Diagram: 1.    Start

How to access the disk data, Q. How to Access the Disk Data? Disks oper...

Q. How to Access the Disk Data? Disks operate is semi-random mode of operation and generally referenced block wise. The data access time on a disk comprises two major component

Microprocessor MIPS Full Adder and Divider with overflow, I need to write a...

I need to write a 32 bit adder in MIPS without using the Add command and a divider as well.

Syntax and semantics - first-order logic, Syntax and Semantics: Propos...

Syntax and Semantics: Propositional logic is prohibited in its expressiveness: so just to represent true and false facts for the world. By a type of extending propositional lo

What happens to logic after synthesis, What happens to logic after synthesi...

What happens to logic after synthesis, which is driving an unconnected output port that is left open (, that is, noconnect) during its module instantiation? An unconnected out

what is lrd_stmt?, The lrd_stmt function associates a character string (ge...

The lrd_stmt function associates a character string (generally a SQL statement) with a cursor. This function sets a SQL statement to be processed.

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