Int n-unconditional branch instruction-microprocessor, Assembly Language

Assignment Help:

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.

922_RET.jpg


Related Discussions:- Int n-unconditional branch instruction-microprocessor

Or-logical instruction-microprocessor, OR: Logical OR: The OR instruction ...

OR: Logical OR: The OR instruction carries out the OR operation in the similar way as described in case of the AND operation. The restriction on source and destination operands ar

Dq-dt-assemblers directive-microprocessor, DQ:   Define  Quad word:-  Th...

DQ:   Define  Quad word:-  This directive is taken in use to direct the assembler to reserve 4 words (8 bytes) of memory for the specified variable and can initialise it having

Zero flag, Zero flag: The next line compares the value in register. A ...

Zero flag: The next line compares the value in register. A with the value 1. If they are equivalent, the Zero flag is set (to 1). The next line then jumps to start: only if th

Dec-arithmetic instruction-microprocessor, DEC:  Decrement :- The decremen...

DEC:  Decrement :- The decrement instruction subtracts 1 from the contents of the particular memory location or register. All the conditions code flags except carry flag are affec

Pointer(ptr)-assemblers directive-microprocessor, PTR : Pointer:- The p...

PTR : Pointer:- The pointer operator which is used to declare the type of a variable, label or memory operand. The operator PTR is prefixed by either WORD or BYTE. If the prefi

Input output memory mapped-microprocessor, Memory Mapped I/O Memory I/O...

Memory Mapped I/O Memory I/O devices are mapped into the system memory map with ROM and RAM. To access a hardware  device, simply write or  read  to  those  'special'  addresse

Write an assembly program to find out largest number, Program :  Write an...

Program :  Write an assembly program to find out the largest number from a given unordered array of 8-bit numbers that stored in the locations starting from a known address. S

Input output interface-microprocessor, I/O interface I/O  devices such ...

I/O interface I/O  devices such as displays and keyboards  establish  communication of computer with outside world. Devices may be interfaced in 2 ways Memory mapped I/O and I/

Addressing modes for sequential control-microprocessor, The addressing mode...

The addressing modes for the sequential control transfer instructions are described below:   1. Immediate: Immediate data is a part of instruction,in this type of addressin

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