The offset address in an 8086/8088 is the logical address that the program "thinks about" when it addresses a location in memory. The Execution Unit (EU or CPU) is responsible for generating the offset address. The Bus Interface Unit (BIU), on the other hand, takes the offset address and adds it to four times the selected segment register value in order to determine a real address, which is now 20-bits in length.
Some programs do deal with segment addresses as well - these are called far pointers instead of near pointers - but the program has to do more than one step to load both the offset and the segment address - a complexity created by running in a 16-bit environment.
displacement from base address
Offset address is also known as displacement.By adding this offset value to a base address,address of a specific locaction in memory can be accessed
Physical address in the 8086/8088 is {Selected Segment Register} * 16 + {Effective Offset Address}. It is a 20-bit address .
The 8086/8088 is the general purpose processor. The 8087 is the math co-processor for the 8086/8088.
it primarily running as a 16 bit processor..so it is so called as 8086
The co-processor on an 8086/8088 is the 8087 math co-processor. The motherboard will be designed with an extra socket for the 8087, which then integrates with the 8086/8088 to make a single unified processor.
Each segment in the 8086/8088 is 64KB because that is how Intel designed the microprocessor. The offset address is 16 bits, making the allowable range 64KB. See the related questions link for a further discussion of segmented architecture.
What is the need of segments in 8086 micro-processor? Explain how the address of an instruction is calculated in 8086 using segment register
The 8086/8088 is a 16 bit processor running on a 16 bit (8086) or 8 bit (8088) bus with a 20 bit address bus. In order to obtain the extra 4 bits of addressibility, Intel designed segment registers that are effectively multiplied by four and then added to the 16 bit offset address generated by the instruction. This yields 64K segments of 64KB each, although they overlap each other at a distance of 16 bytes.
8086 means its a 8 bit processor and 86 is its model number
The 8086/8088 can address a maximum of 220, or 1,048,576, or 1 MB of memory.
In the 8086 microprocessor, reading word-sized data is generally faster from an even address than from an odd address. This is because the 8086 architecture is designed to access memory in 16-bit (word) chunks, and even addresses allow the processor to retrieve data more efficiently, aligning with its access patterns. When a word is at an odd address, the processor must perform an additional cycle to fetch the data, resulting in slower access times.