What is effective address calculation?

In the Indexed Register Addressing Mode, the effective address is the sum of the contents of 2 registers. Since, R1 here acts as the index register and the address field contains the value 400, hence Effective Address = 200 + 400 = 600.

What is meant by the effective address that is generated by the processor for a machine instruction?

The instruction which uses processor registers to represent operands is the instruction in register addressing mode. Here, the effective address is a register where the value of the operand is present.

What does effective address mean?

An effective address is any operand to an instruction which references memory. Effective addresses, in NASM, have a very simple syntax: they consist of an expression evaluating to the desired address, enclosed in square brackets.

What is the purpose of addressing modes?

An addressing mode specifies how to calculate the effective memory address of an operand by using information held in registers and/or constants contained within a machine instruction or elsewhere.

What is effective address and physical address?

Physical Address will have to be calculated Physical Address : Actual address of a byte in memory. Here, the effective address of the memory location at which the data operand is stored is given in the instruction. The effective address is just a 16-bit number written directly in the instruction.

How do you calculate an effective address from a 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. The memory in the 8086 architecture is 1M.

How do you calculate effective address in computer architecture?

EA= PC + Address field value PC= PC + Relative value. Base register addressing mode:Base register addressing mode is used to implement inter segment transfer of control.In this mode effective address is obtained by adding base register value to address field value. EA= Base register + Address field value.

What is effective address and physical address in 8086?

Effective Address or Offset Address: It is an unassigned 16 bit number that expresses the operand’s distance in bytes from the beginning of the segment in which it resides. In 8086 we have base registers and index registers. The displacement is an 8 or 16 bit number that is contained in the instruction.

How effective address is calculated in immediate addressing mode?

The effective address of the memory operand is found by adding the base address in register rs to the sign-extended 16-bit offset found in the immediate field.

What are the advantages of relative addressing mode over direct addressing mode?

“The advantage of using relative mode over direct mode is that relative addressing is a code which is position-independent, i.e. it can be loaded anywhere in memory without the need to adjust any addresses.”

How is the effective address of base register calculated Mcq?

Base Register addressing mode: In this mode effective address is calculated by adding base register value to address field value. Relative Address mode: In this mode, effective address is calculated by adding accumulator and value in address part of the instruction.

How does a CPU generate a logical address?

That said, commonly logical addresses are not generated by the CPU, CPUs just use logical addressing to do memory lookups. They need another entity to map logical addresses to actual physical memory locations. Why?

What is the difference between absolute and PC-relative instruction addresses?

The effective address for an absolute instruction address is the address parameter itself with no modifications. The effective address for a PC -relative instruction address is the offset parameter added to the address of the next instruction. This offset is usually signed to allow reference to code both before and after the instruction.

What is physical address in computer architecture?

Physical Address identifies a physical location of required data in a memory. The user never directly deals with the physical address but can access by its corresponding logical address.

Why logical address is called virtual address?

The logical address is virtual address as it does not exist physically, therefore, it is also known as Virtual Address. This address is used as a reference to access the physical memory location by CPU.