Physical memory mapped and port input output-microprocessor, Assembly Language

Assignment Help:

Physical Memory Mapped I/O and Port I/O :

CPU controlled I/O comes in 2 ways. Simply the difference is whether we utilize the normal memory addresses for I/O, this is mention to as physical memory mapped I/O, or whether we set up a completely separate section of memory addresses which may ONLY be used for I/O, called port or I/O mapped I/O and addressed I/O Thus the latter has 2 separate addressing areas for the CPU, one for normal (physical) memory, one for I/O, while the former has only one which serves both purposes.The other difference between these 2techniques is that with memory mapped I/O the similar processor instructions that are utilized for transferring data to and from the processor registers and memory, or for testing the content of a memory register and so on, are utilized for the I/O operation, whereas port-addressed I/O has particular instructions (load and store) which may only be used for I/O operations, and have different codes and mnemonics.  In  the case  data  might always  be  transferred  into  a  processor  register, and in the  latter instructions like SUB,ADD (subtract) and CMP (compare) can refer to the input/output registers.

The peripheral controller serves to put the data at the proper memory locations, memory mapped or port addressed as can be. It will also provide control registers to determine whether data can be inputted or outputted, that is whether the external connections are for input or output of data, since they are often shared. The processor cannot read and write at the same location, it must do 1 or the other.

Also there will be a 'status' register which contain various 'flags' which signal to the processor that some of data has been placed for reading. Some of these can also be observable as connections to the outside world, to show, for instance, that the processor has supplied data for output. The registers are the similar size as the computer memory locations, generally 8-bit,-byte sized, so that they generally occupy 1 memory address each. The real number of addresses depends on the complication and functions provided by the peripheral controller

 


Related Discussions:- Physical memory mapped and port input output-microprocessor

Write a program to find the average of the array , Write a program on the a...

Write a program on the assembly language to do the following: 1- Allocate array with 32bit 100 element 2- Prompt the user to enter the maximum or the upper bound of the rando

L.A, How is bob different from johnny in the outsiders

How is bob different from johnny in the outsiders

Assigment help, assempbly language routine that takes an array named A cont...

assempbly language routine that takes an array named A containing n bytes of postive numebrs and fills two arranys, array B containing n words and array C containing n long words

Project, Any small project which can implement on any software. No need any...

Any small project which can implement on any software. No need any external hardware approach.

.., Sum of series of 10 numbers and store result in memory location total

Sum of series of 10 numbers and store result in memory location total

Write an 8086 assembly program, Project Description: Write an 80x86 asse...

Project Description: Write an 80x86 assembly program that performs the following functions: Reads a set of integers from a file into an array. The data file name is to be

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

Help with assemly language assignment, Will be needing help with assembly l...

Will be needing help with assembly language assignments over the course of 4 weeks

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