microprocessor architecture divided in The BIU has to interact with memory and of the programs and to carry out the required processing. EU & BIU. Explanation of the purpose of EU and BIU in Bus Interface Unit (BIU): The BIU interface to outside word. It provides full 16 bit. Define the jobs performed by the BIU and EU in the The functions performed by the Bus interface unit are: The BIU is responsible for the external bus.

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Segmented memory can seem confusing at first. The physical address is 20 bits long and corresponds to the actual binary code output by the BIU on the address bus lines.

The instruction execution cycle is never broken for fetch operation. It holds the addresses of instructions micoprocessor data in memory, which are used by the processor to access memory locations. With regard to this, you might wonder if all words must begin at an even address.

The last few paragraphs apply only to the However they are specially to hold the bit offset of the data word. Microprocessor and Computer Architecture execution unit.

Fortunately for the programmer, except for the slightly slower performance of thethere is no difference between the two processors.

All general registers of the microprocessor can be used for arithmetic and logic operations. These are set or reset by the EU on the basis of the results of some arithmetic or logic operation. This is a process to speed up the processor. Newer Post Older Post Home.


Second, many of the ‘s and ‘s operation codes are single bytes. SI register is also used for andd a offset of a data word in Data segment. Another way if saying this is that the low-order hex digit must be 0. During this execution time the BIU fetches the next instruction or instructions from memory into the instruction queue instead of remaining idle. We think you have liked this presentation. A logical address gives the displacement from the address base of the segment to the desired location within it, as opposed to its microproceessor address, which micgoprocessor directly anywhere into the 1 MB memory space.

A decoder in the EU translates the instructions fetched from memory into a series of actions which the EU performs. The CPU must perform two memory read cycles: The Microprocwssor has a dedicated order. Source Index SI is a bit register.

IP contains the address of the ru instruction to executed by the EU. These registers can be used individually to store 8-bit data and can be used in pairs to store 16bit data. This feature is called as Pipelining and this is what makes a powerful processor of that time. Sends out addresses Fetches instructions from memory. In thethe BIU data bus path is 8 microprocesosr wide versus the ‘s bit data bus.

Introduction to 8086 Microprocessor

An immediate advantage of having separate data and code segments is that one program can work on several different sets of data. It does so by appending the 16bit address in segment register by 0H 8068 then adding the offset address. ALU is 6 bit. The queue is updated after every byte is read from the queue but the fetch cycle is entreated by BIU only if at least two bytes of the queue are empty and the EU may be concurrently executing the fetched instructions.


By passing the data back to the BIU, data can also be stored in a memory micdoprocessor or written to an output device.

Write short notes on the Execution Unit (EU) and the Bus Interface Unit (BIU).

When i is necessary to access a word whether on an even- or an odd-addressed boundary two memory read or write cycles are performed. Note that each can be accessed as a byte or a word.

Overall, these are used to hold the offset address of the stack address. They are used to control certain operations of the processor.

Stack operations use registers BP or SP and the stack segment.

To increase the speedThe BIU pre-fetches almost six bytes of the next instruction. Thus BX refers to the bit base register but BH refers only to the higher 8 bits of this register.

There are four types of Segment registers. These all 4 segment registers holds the addresses of instructions and data in memory. They are dependent and get worked by each other.

The two pointer registers, SP and BP are used to access data in the stack segment. CS register cannot be changed directly.

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