How to Program and Interface the 8086 Microprocessor: A Free PDF Resource
8086 Microprocessor PDF Download Free
If you are interested in learning about the 8086 microprocessor, one of the most popular and influential microprocessors in history, you might want to download a PDF file that contains all the information you need. In this article, we will provide you with a comprehensive overview of the 8086 microprocessor, its architecture, instruction set, programming model, memory organization, interrupts, input/output interface, applications, advantages, disadvantages, comparison with other microprocessors, and how to download a PDF file for free. By the end of this article, you will have a clear understanding of the 8086 microprocessor and its significance in the field of computer science.
8086 microprocessor pdf download free
What is 8086 Microprocessor?
A microprocessor is a small electronic device that performs arithmetic and logic operations on binary data. It is also known as a central processing unit (CPU) or a processor. A microprocessor consists of several components, such as an arithmetic logic unit (ALU), a control unit (CU), registers, buses, etc., that work together to execute instructions.
The 8086 microprocessor is a 16-bit microprocessor that was developed by Intel Corporation in 1978. It was the first member of the x86 family of microprocessors, which are still widely used today. The 8086 microprocessor has several features that make it unique and powerful, such as:
It can operate in two modes: minimum mode and maximum mode. In minimum mode, it can work as a single processor system with minimal external components. In maximum mode, it can work as a multiprocessor system with additional coprocessors.
It can address up to 1 MB of memory using 20-bit physical addresses. It can also access up to 64 KB of memory using 16-bit logical addresses.
It can perform up to four million instructions per second (MIPS) at a clock speed of 5 MHz.
It can support up to 256 input/output (I/O) devices using special instructions.
It can handle up to eight types of interrupts and four types of exceptions.
It can execute both binary-coded decimal (BCD) and binary arithmetic operations.
It can support both big-endian and little-endian byte ordering.
Architecture of 8086 Microprocessor
The architecture of the 8086 microprocessor refers to the internal structure and organization of its components and functions. The architecture of the 8086 microprocessor can be divided into two parts: the bus interface unit (BIU) and the execution unit (EU).
The BIU is responsible for fetching instructions from memory, decoding them, and transferring them to the EU. It also handles the address generation and data transfer between the microprocessor and the external devices. The BIU consists of four 16-bit registers: the instruction pointer (IP), the code segment (CS), the data segment (DS), and the extra segment (ES). The IP holds the address of the next instruction to be executed. The CS, DS, and ES hold the base addresses of the code, data, and extra segments in memory, respectively.
The EU is responsible for executing the instructions fetched by the BIU. It also performs arithmetic and logic operations on data. The EU consists of four 16-bit registers: the accumulator (AX), the base (BX), the count (CX), and the data (DX). The AX, BX, CX, and DX can be used as general-purpose registers or as two 8-bit registers: AH/AL, BH/BL, CH/CL, and DH/DL, respectively. The EU also consists of two 16-bit registers: the stack pointer (SP) and the base pointer (BP). The SP holds the address of the top of the stack in memory. The BP holds the address of the base of the current procedure or function in memory. The EU also consists of two 16-bit registers: the source index (SI) and the destination index (DI). The SI and DI are used for string operations and hold the addresses of the source and destination operands in memory, respectively. The EU also consists of a 16-bit flag register (FLAGS) that holds various status bits that indicate the result of an operation or the state of the microprocessor.
Instruction Set of 8086 Microprocessor
The instruction set of the 8086 microprocessor refers to the set of instructions that it can execute. An instruction is a binary code that tells the microprocessor what to do. An instruction consists of two parts: an opcode and an operand. The opcode specifies the operation to be performed, such as add, subtract, move, etc. The operand specifies the data or address involved in the operation, such as a register, a memory location, an immediate value, etc.
The instruction set of the 8086 microprocessor can be classified into six types:
Data transfer instructions: These instructions are used to move data between registers, memory locations, or I/O devices. Examples are MOV, PUSH, POP, IN, OUT, etc.
Arithmetic instructions: These instructions are used to perform arithmetic operations on data, such as addition, subtraction, multiplication, division, etc. Examples are ADD, SUB, MUL, DIV, etc.
Logical instructions: These instructions are used to perform logical operations on data, such as AND, OR, XOR, NOT, etc. Examples are AND, OR, XOR, NOT, etc.
Shift and rotate instructions: These instructions are used to shift or rotate bits in a register or a memory location. Examples are SHL, SHR, ROL, ROR, etc.
Branch instructions: These instructions are used to change the sequence of execution based on a condition or an address. Examples are JMP, CALL, RET, JZ, JNZ, etc.
String instructions: These instructions are used to perform operations on strings of bytes or words in memory. Examples are MOVSB, MOVSW, CMPSB, CMPSW, etc.
The format of an instruction in the 8086 microprocessor can be one of four types:
Type 1: Opcode only. Example: HLT
Type 2: Opcode + Register/Memory Operand. Example: INC AX
Type 3: Opcode + Register/Memory Operand + Immediate Operand. Example: ADD AL, 10
Type 4: Opcode + Register/Memory Operand + Register/Memory Operand. Example: MOV AX,BX
Programming Model of 8086 Microprocessor
The programming model of the 8086 microprocessor refers to how a programmer can use its registers and addressing modes to write programs. A register is a small storage location inside the microprocessor that can hold data or addresses. An addressing mode is a way of specifying an operand in an instruction.
The programming model of the 8086 microprocessor consists of four types of registers:
Data registers: These are AX,BX,CX,and DX that can be used for storing data or performing arithmetic and logic operations.
Pointer registers: These are SP,BP,Si,and DI that can be used for pointing to locations in memory or performing string operations.
Segment registers: These are CS,D 71b2f0854b