How do you calculate physical address if logical address is given?

1. If Logical Address = 31 bit, then Logical Address Space = 231 words = 2 G words (1 G = 230)
2. If Logical Address Space = 128 M words = 27 * 220 words, then Logical Address = log2 227 = 27 bits.
3. If Physical Address = 22 bit, then Physical Address Space = 222 words = 4 M words (1 M = 220)

How do you calculate physical address?

I learnt that the physical address is calculated by shifting the segment address (16-bit) left 4 times and adding it with the 16-bit offset address.

What are the physical addresses of following logical addresses?

• First-fit.
• 212K is put in 500K partition.
• 417K is put in 600K partition.
• 112K is put in 288K partition(new partition 288K=500K-212K)
• 426K must wait.
• Best-fit.
• 212K is put in 300K partition.
• 417K is put in 500K partition.

How do you calculate physical and virtual addresses?

To help you solve this question, we need to get our details right: 16 bit of virtual address space = 2^16 = 65,536 address space. 16 bit of physical address space = 2^16 = 65,536 address space. 4096 Byte page size determines the offset, which is Log(4096) / Log (2) = 12 bit.

What is the formula to calculate physical memory address of a page?

Calculation of the number of bits required for Physical Address: # Physical Address Space (PAS) =Size of main memory. # Physical Address Space (PAS) is divided into an equal number of frames. # Page size = frame size which is always a power of 2.

How can I get physical address in 8086?

in 8086 microprocessor a 20 bit address is divided in 16bit+4bit address in which 4 bit binary is the segment address.

What are the physical addresses for the following logical addresses A 0 430?

Segment 0, Logical Address is 430 – So physical address becomes – 219+430 = 649 b. Segment 1, Logical Addres is 10 – So physical address becomes – 2300+10 = 2310.

What is the difference between logical address and physical address?

The basic difference between Logical and physical address is that Logical address is generated by CPU in perspective of a program whereas the physical address is a location that exists in the memory unit.

How do you calculate physical address from segment offset pairs?

In particular, given a [segment:offset] pair, a 20-bit external (or physical) address is produced by segment × 24 + offset, where segment × 24 is called the segment address, which has its 16 most significant bits from the 16-bit segment register, and its four LSbs are all zeros.

How do you find the 20 bit physical address?

To generate the 20-bit address, the CPU shifts the segment 4 bits (1 hex digit) to the left and adds the offset to it. A common combination for segment and offset is the CS and IP registers: together they indicate the address of the next instruction.

What is the length of physical address?

Explanation: Physical Address Space = 2P Bytes. Word Length is 2W bytes, which means each word is of size 2W bytes. Cache memory size = 2N Bytes and Tag Size = 2X Bytes.

What is physical address and logical address in 8086?

The physical address is the 20-bit address that is actually put on the address pins of the 8086 microprocessor and decoded by the memory interfacing circuitry. The offset address is a location within a 64K-byte segment range. The logical address consists of a segment value and an offset address.

What is the difference between logical address and physical address 8086?

The basic difference between Logical and physical address is that Logical address is generated by CPU in perspective of a program whereas the physical address is a location that exists in the memory unit.

How is a 20-bit address obtained if there are only 16-bit registers?

First, we shift the first address by four bits to the left: 7 2 3 A 0 which is called the base. Then, we add the the second address: 0 0 0 5 which is called the offset. The result of this operation is a new 20-bit address: 7 2 3 A 5 .

What happens if the logical address is segment ID 2 and offset 1000 explain the answer?

Explanation: Segment-2 has a base address = 1527 and limit address = 498, So it can only access the memory location from 1527 till 1527 + 498, if the process tries to access the memory with offset 1000 then a segmentation fault trap will be generated.

How much the number of bits calculation required for the logical address if you considered the segment size is 1 K bytes and there are 32 segments?

To specify a particular segment, 5 bits are required (since 2^5 = 32). Having selected a page, to select a particular byte one needs 10 bits (since 2^10= 1K byte). So, totally 5 + 10 =15 bits are needed.

How do you calculate page numbers and offset of virtual address?

1. this is the distance from the beginning of the page.
2. e.g. address in the process, A = 10,000.
3. page size = 4k.
4. page offset = 10000 mod 4k = 10,000 mod 4096 = 1908.
5. this calculation is done quickly on the computer since the page size is power of 2, e.g., 4k = 2^12.

Is IP address logical or physical?

An IP address is a logical address that is assigned by software residing in the router or server, and that logical address can change from time to time. For example, a laptop is likely to be assigned a new IP when it starts up in a different hotspot (see DHCP).

What is offset in logical address?

The last bits of the virtual address are called the offset which is the location difference between the byte address you want and the start of the page. You require enough bits in the offset to be able to get to any byte in the page.

How is 20 bit physical address calculated 8086?

At any given time, 8086 can address 16-bit x 64KB = 256 KB of memory chunk out of 1MB. 8086 has 20bit address line. So the maximum value of address that can be addressed by 8086 is 2^20 = 1MB. So 8086 can address the locations ranging between 00000 H to FFFFF H.

What do they mean by physical address?

A physical address, sometimes referred to as a street address, is used to describe where a place is geographically located. It often pertains to a geographic location under the jurisdiction of an administrative area or region that has some government function.

Why does 8086 have 20 bit address bus rather than 16-bit?

Answering narrowly just your question: because the 8086 uses 8-bit addressing, not 16-bit. Even when using the 8086 with its full 16-bit data bus (vs. the 8088 which had an 8-bit bus), the addresses point to individual bytes, not 16-bit words.

How does 8086 manage a 20 bit address in a 16-bit processor?

It is a 16-bit Microprocessor having 20 address lines and16 data lines that provides up to 1MB storage. It consists of powerful instruction set, which provides operations like multiplication and division easily. It supports two modes of operation, i.e. Maximum mode and Minimum mode.

How are the segment registers used to form 20 bit physical address?

5.1. A segment register changes the memory address accessed by 16 bits at a time, because its value is shifted left by 4 bits (or multiplied by 16) to cover the entire 20-bit address space. The segment register value is added to the addressing register’s 16-bit value to produce the actual 20-bit memory address.

What are the methods of generating physical address of memory locations?

There are several techniques used for address translation in non contiguous memory allocation like Paging, Multilevel paging, Inverted paging, Segmentation, Segmented paging.