Features of 8086 Microprocessor:
The features of 8086 Microprocessor are :
1.The 8086 is a 16-bit microprocessor. The term “16-bit” means that its arithmetic logic unit, internal registers and most of its instructions are designed to work with 16-bit binary words.
2.The 8086 has a 16-bit data bus, so it can read data from or write data to memory and ports either 16 bits or 8 bits at a time. The 8088, however, has an 8-bit data bus, soil can only read data from or write data to memory and ports 8 bits at a time.
3.The 8086 has a 20-bit address bus, so it can directly access 220 or 10,48,576 (1Mb) memory locations. Each of the 10, 48, 576 memory locations is byte Therefore, a sixteen-bit words are stored in two consecutive memory locations. The 8088 also has a 20-bit address bus, so it can also address 220 or 10, 48, 576 memory locations.
4.The Features of 8086 Microprocessor can generate 16-bit I/O address, hence it can access 216 = 65536 I/O ports.
5.The 8086 provides fourteen 16-bit registers.
6.The 8086 has multiplexed address and data bus which reduces the number of pins needed, but does slow down the transfer of data (drawback).
7.The 8086 requires one phase clock with a 33% duty cycle to provide optimized internal timing.
Range of clock rates (refer Fig. 6.1) are :-
5 MHz for 8086
8 MHz for 8086-2
10 MHz for 8086-1
8.The Features of 8086 Microprocessor is possible to perform bit, byte, word and block operations in 8086. It performs the arithmetic and logical operations on bit, byte, word and decimal numbers including multiply and divide.
9.The Intel 8086 is designed to operate in two modes, namely the minimum mode and the maximum mode. When only one 8086 CPU is to be used in a microcomputer system, the 8086 is .used in the minimum mode of operation. In this mode the CPU issues the control signals required by memory and I/O In multiprocessor (more than one processor in the system) system 8086 operates in maximum mode. In maximum mode, control signals are generated with the help of external bus controller (8288).
10.The Intel 8086 supports multiprogramming. In multiprogramming, the code for two or more processes is in memory at the same time and is executed in a time-multiplexed fashion.
11.An interesting feature of the 8086 is that it fetches up to six instruction bytes (4 instruction bytes for 8088) from memory and queue stores them in order to speed up instruction execution.
12.The Features of 8086 Microprocessor provides powerful instruction set with the following addressing modes : Register, immediate, direct, indirect through an index or base, indirect through the sum of a base and an index register, relative and implied.