INT N : Interrupt Type N:-

In the interrupt structure of 8086/8088, 256 interrupts are distinct equivalent to the types from OOH to FFH. When an instruction INT N is executed, the TYPE byte N is multiplied by value 4 and the contents of IP and CS register of the interrupt  service routine will be taken from hexadecimal multiplication (Nx4) as offset address and 0000 as the segment address. In other terms, the multiplication of type N by value 4 (offset) points to a memory block in the 0000 segment, which have the IP and CS register values of the interrupt service routine.

For the execution of this instruction, the IF ought to be enabled.

Example :

Therefore the instruction INT 20H will find out the address of the interrupt service routine as follows:

INT       20H

Type* 4 = 20 * 4 = 80H

Pointer to CS and IP of the ISR is 0000: 0080 H

Given figure shows the arrangement of CS and IP  register addresses of the ISR in the interrupt vector table.

Posted Date: 10/12/2012 4:06:18 AM | Location : United States

Ask an Expert

Related Discussions:- Int n-unconditional branch instruction-microprocessor, Assignment Help, Ask Question on Int n-unconditional branch instruction-microprocessor, Get Answer, Expert's Help, Int n-unconditional branch instruction-microprocessor Discussions

Write discussion on Int n-unconditional branch instruction-microprocessor
Your posts are moderated

Write your message here..

Related Questions

Selecting array elements, implement the following c++ code in assembly lang... implement the following c++ code in assembly language using the block-structured .IF and .while directives

Assignment, You have to write a subroutine (assembly language code using NA... You have to write a subroutine (assembly language code using NASM) for the following equation. Dx= ax2+(ax-1)+2*(ax+2)/2

Login system, a pseudo-code to add username and password combination up to ... a pseudo-code to add username and password combination up to a limit of 10

The 486, The 486 Introduced in the year 1989 the 80486 did not feature ... The 486 Introduced in the year 1989 the 80486 did not feature any radically new processor technology. Instead, it joints a 386 processor, a cache memory controller and a math c

Pin description of 8086-microprocessor,  Pin Description of 8086 The ...  Pin Description of 8086 The microprocessor 8086 is a 16-bit CPU available in 3 clock rates, for example 5, 8 and 10 MHz, packaged in a40 pin CERDIP or plastic package. The 8

Sahf instrucions, what is sahf nstrucions what is sahf nstrucions

ISBN CHECK, How do i convert a asci number to numerals? How do i convert a asci number to numerals?

Lds/les instruction execution-microprocessor, LDS/LES Instruction execution... LDS/LES Instruction execution :  LAHF : Load AH from Lower Byte of Flag: - This instruction loads the AH register with the lower byte of the flag register. This instruction ca

Assembly Language Programming, Write a program that defines symbolic consta... Write a program that defines symbolic constants for all of the days of the week

Relocate program and data, ) What is the difference between re-locatable pr... ) What is the difference between re-locatable program and re-locatable data?