What are segment and offset addresses?

The distance in bytes from the segment address to another location within the segment is expressed as an offset (or displacement). A segment is an area of memory that includes up to 64K bytes as shown in the following figures. The offset address is always added to the segment starting address to locate the data.

What is segment address in assembly language?

Each segment is used to contain a specific type of data. One segment is used to contain instruction codes, another segment stores the data elements, and a third segment keeps the program stack.

How do you find the physical address from segment 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.

What are segment registers?

Segment Registers Segments are specific areas defined in a program for containing data, code and stack. There are three main segments − Code Segment − It contains all the instructions to be executed. A 16-bit Code Segment register or CS register stores the starting address of the code segment.

How are segments addressed?

The segment address is always added to a 16-bit offset in the instruction to yield a linear address, which is the same as physical address in this mode….Real mode.

0000 0110 1110 1111 0000	Segment,	16 bits, shifted 4 bits left (or multiplied by 0x10)
0000 1000 0001 0010 0100	Address,	20 bits

How many segments are there in 8086?

four
The 8086 has four special segment registers: cs, ds, es, and ss. These stand for Code Seg- ment, Data Segment, Extra Segment, and Stack Segment, respectively. These registers are all 16 bits wide.

What is the use of extra segment in 8086?

The es (Extra Segment) register is an extra segment register. 8086 programs often use this segment register to gain access to segments when it is difficult or impossible to modify the other segment registers.