Describe about address space and memory space, Computer Engineering

Assignment Help:

Q. Describe about Address Space and Memory Space?

An address used by a programmer will be termed as a virtual address and set of such addresses the address space. An address in main memory is known as a physical address. The set of these locations is termed as memory space. So address space is set of addresses produced by programs as they reference instructions and data, memory space comprises actual main memory locations directly addressable for processing.

Supposes a computer which has a main-memory capacity of 64K words (K=1024). 16-bits are required to specify a physical address in memory because 64K = 216. Assume that computer has auxiliary memory for storing information equivalent to capacity of 16 main memories. Let's signify address space by N and memory space by M we then have for this illustration: N = 16 × 64 K = 1024K and M = 64K.

In a multiprogramming computer system, data and programs are transferred to and from auxiliary memory and main memory based on demands obliged by CPU. Suppose program 1 is currently being executed in CPU. Program 1 and a part of its associated data are moved from secondary memory in the main memory as displayed in Figure below. Parts of programs and data require not being in contiguous locations in memory because information is being moved in and out and empty spaces may be available in scattered locations in memory.

1319_Describe about Address Space and Memory Space.png

Figure: Address and Memory Space in Virtual Memory

In our illustration address field of an instruction code will comprise 20 bits however physical memory addresses should be specified with just 16-bits. So CPU will reference data and instructions with a 20 bits address though information at this address should be taken from physical memory since access to auxiliary storage for particular words will be prohibitively long. A mapping table is then required as displayed in Figure below to map a virtual address of 20 bits to a physical address of 16 bits. Mapping is a dynamic operation that means every address is translated instantly as a word is referenced by CPU.  

323_Describe about Address Space and Memory Space1.png

Figure: Memory table for mapping a virtual table


Related Discussions:- Describe about address space and memory space

Explain the term- looking at existing paperwork, Explain the term- Looking ...

Explain the term- Looking at existing paperwork This allows analyst to see how paper files are kept and look at operating instructions and check accounts, training manuals etc

Explain physical characteristics of magnetic disk, Q. Explain Physical Char...

Q. Explain Physical Characteristics of magnetic disk? Figure below lists main features that differentiate among different types of magnetic disks. First head may either be fixe

Determine the types of sensors, Determine the types of Sensors Differe...

Determine the types of Sensors Different types of sensors are used to give real time information to computers. Frequently, an analogue to digital converter (ADC) is required a

Analysis of merge sort, i) The width of the sorting + merging circuit is eq...

i) The width of the sorting + merging circuit is equivalent to maximum number of devices needed in a phase is O(n/2). As in the above diagram maximum number of devices for a given

Explain switch statement, Switch This is another form of the multi way ...

Switch This is another form of the multi way decision. It is well structured, but can only be used in certain cases where; Only one variable is tested, all branches must

Support activities in supply chain management, What are the some support ac...

What are the some support activities in primary functions of Supply Chain Management? To support primary functions of Supply Chain Management there will be a company’s infrastr

Define the circular shifts, Q. Define the Circular shifts ? Circular sh...

Q. Define the Circular shifts ? Circular shifts ROTATE RIGHT andROTATE LEFT. Bits shifted out at one end of word are not lost as in a logical shift however are circulated back

Elaborate the memory devices - semiconductor memory, Elaborate the memory ...

Elaborate the memory devices  - Semiconductor memory All of the memory used as main store in a modern computer is applied as semiconductors fabricated on wafers of silicon. Sem

Illustrate about object oriented development, Illustrate about object orien...

Illustrate about object oriented development object oriented development is not direct way of system development as in this approach a holistic view of application domain is co

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