What are segments 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.
What is the function of segment registers?
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.
Where are the segment registers located?
Segment registers are basically memory pointers located inside the CPU.
Why do we have segment registers in 8086?
It allows to processes to easily share data. It allows to extend the address ability of the processor, i.e. segmentation allows the use of 16 bit registers to give an addressing capability of 1 Megabytes. Without segmentation, it would require 20 bit registers.
What is the purpose 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. The ss (Stack Segment) register points at the segment containing the 8086 stack.
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.
What is the purpose of multiple segments in 8086?
8086 uses 20bit address bus, but its internal registers are 16bit. Hence segmentation helps addressing ( CS:IP or SS:SP). More over you can also build relocatable code with help of segments. You can load your code to any part of the memory and access it only by changing the segment register.
What is the function of base register?
The function of Base registers is typically to keep stock of the population at any given time. In addition, they have to maintain identification information to be used by other Data Sources.