What is physical address generation?

Differences Between Logical and Physical Address in Operating System. 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.

What is physical address in microprocessor?

In computing, a physical address (also real address, or binary address), is a memory address that is represented in the form of a binary number on the address bus circuitry in order to enable the data bus to access a particular storage cell of main memory, or a register of memory-mapped I/O device.

What do you mean by physical and logical address of 8086?

Physical Address is the 20-bit address that actually put on the address bus. (in 8086) ❖ Has a range of 00000H – FFFFFH ▪ Segment Address is a 16-bit address of the segment block. Has a range of 0000H – FFFFH ▪ Logical Address consists of segment address and offset address.

How do you calculate physical address?

To compute the physical address:

1. look up the page number in the page table and obtain the frame number.
2. to create the physical address, frame = 17 bits; offset = 12 bits; then 512 = 29. 1m = 220 => 0 – ( 229-1 ) if main memory is 512 k, then the physical address is 29 bits.

What is physical address and its size?

Physical address space in a system can be defined as the size of the main memory. It is really important to compare the process size with the physical address space. The process size must be less than the physical address space.

What is logical and physical address?

The logical address is a virtual address and can be viewed by the user. The fundamental difference between logical and physical address is that logical address is generated by CPU during a program execution whereas, the physical address refers to a location in the memory unit.

What is physical address space?

Physical address space in a system can be defined as the size of the main memory. It is really important to compare the process size with the physical address space. The process size must be less than the physical address space. Physical Address Space = Size of the Main Memory.

What is the size of physical address in 8086 microprocessor?

The 8086 processor has a 20-bit address bus, which gives a physical address space of up to 1 MB (220), addressed as 00000h to FFFFFh.

What defines a physical address in context of a program?

The physical address refers to a location in the memory. It allows access to data in the main memory. A physical address is not directly accessible to the user program hence, a logical address needs to be mapped to it to make the address accessible. This mapping is done by the MMU.

What is the address range of the 8086 microcontroller?

So 8086 can address the locations ranging between 00000 H to FFFFF H. This 1MB memory is divided into 16 logical segments, each with a memory of 64KB. To locate any adress in the memory bank, it needs the Physical address of that memory location. It cannot get the 20-bit Physical adress using the 8086 Address Line or 16-bit Segment Registers alone.

What is the size of a segment register in 8086?

Each Segment has a corresponding 16-bit Segment Register which holds the Base Address (starting Address) of the Segment. At any given time, 8086 can address 16-bit x 64KB = 256 KB of memory chunk out of 1MB. 8086 has 20bit address line.

How to get 20-bit physical address from 8086 address line?

It cannot get the 20-bit Physical adress using the 8086 Address Line or 16-bit Segment Registers alone. In order to access memory location, you cannot pass 20-bit address directly to the processor.

How much memory can 8086 address in 1MB?

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. This 1MB memory is divided into 16 logical segments, each with a memory of 64KB.